-
AccuchillerAQ SeriesAir and Water Cooled
Operation and Installation Manual
Thermal Care, Inc.7720 N. Lehigh Ave.Niles, IL 60714-3491
Phone (847) 966-2260Fax (847) 966-9358E-mail
[email protected] www.thermalcare.com
Customer ServicePhone (847) 966-2636Fax (847) 966-2906
PartsPhone (847) 966-8560Fax (847) 966-6065
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Page 2
Page No.Foreword 3Pre-Installation 5
Receiving Inspection 5Rigging, Handling & Locating Equipment
5
Installation 7Electrical Power 7Air Cooled Condenser (Air Cooled
Chillers Only) 7Condenser Water Lines (Water Cooled Chillers Only)
8Required Condenser Water Flow Table 9Chilled Water Lines
9Suggested Chilled Water Flow Table 10Suggested Pipe Sizing Table
11Overhead Piping Diagram 11
Chiller Start-Up 12Recommended Glycol Mixtures Table 13
Control Panel Operation 15Control Panel Diagram 15Microprocessor
Control Fault Logic Table 15Control Buttons 16Diagnostic LEDs
18Diagnostic Error Codes 21Control Options 22
Chiller Operation 26Typical Piping Schematic Diagram 26Coolant
Circuit 27Refrigerant Circuit 28
Chiller Construction 30Refrigeration Components 30Wet-Side
Components 34Operating and Safety Controls 36
Standard Options 38Preventive Maintenance 40
Preventive Maintenance Checklist 42Troubleshooting 43Pump Curves
47Diagrams 48
AQ0A0H Wiring Diagram 48AQ0A01 Wiring Diagram 49AQ0A02 - AQ0A10
Wiring Diagram 50AQ0W02 - AQ0W05 Wiring Diagram 51AQ0W08 - AQ0W10
Wiring Diagram 52AQ1W05 - AQ1W15 Wiring Diagram 53AQ1W20 - AQ1W30
Wiring Diagram 54AQ1W35 - AQ1W40 Wiring Diagram 55
Air Cooled Dimensions 56Water Cooled Dimensions 57Warranty
58
TABLE OF CONTENTS
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FOREWORD
The intent of this manual is to serve as a guide for placing
your por-table chiller in service, and operating and maintaining it
properly.This manual will be supplemented as required to
accommodate anyspecial items which may have been provided for a
specific application.The written information contained in this
manual, as well asvarious drawings, are intended to be general in
nature. Theschematics included in this manual are typical only.
Actual schemat-ics are included in the electrical enclosure of the
chiller and should bereferred to for troubleshooting and servicing
of the unit. Additionalcopies of wiring diagrams are available upon
request. We strive tomaintain an accurate record of all equipment
during the course of itsuseful life. While every effort is made to
standardize the designfeatures of these chillers, the various
options may make it necessaryto rearrange some of the components;
therefore, some of the generaldrawings in this manual may differ
from your specific unit.
Specific references to current applicable codes, ordinances, and
otherlocal laws pertaining to the use and operation of this
equipment areavoided due to their ever changing nature. There is no
substitute forcommon sense and good operating practices when
placing any me-chanical equipment into operation. We encourage all
personnel tofamiliarize themselves with this manuals contents.
Failure to do somay unnecessarily prolong equipment down time.
Our chilling equipment uses chemical refrigerants for heat
transferpurposes. This chemical is sealed and tested in a
pressurized systemcontaining ASME coded vessels; however,
refrigerant gas can bereleased if there is a system failure.
Refrigerant gas can cause toxicfumes if it is exposed to fire.
These units must be placed in a wellventilated area, especially if
open flames are present. Failure tofollow these instructions could
result in a hazardous condition.
The standard refrigerant used in these units is a
hydrochloro-fluoro-carbon (HCFC) trade named R-22. The EPA has
enacted laws regard-ing the handling of refrigerants and eventual
phaseout of HCFCrefrigerants. HCFC refrigerant production will
continue until Janu-ary 1, 2010 for new equipment and until January
1, 2020 for servicepurposes. Customers are advised to immediately
implement a refrig-erant management program including a survey of
all equipment todocument the type and quantity of refrigerant in
each machine. Allrefrigeration service technicians must be
certified by an EPA ap-proved organization.
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It is recommended that good piping practices are followed and
thatthe information in this manual is adhered to. We cannot be
heldresponsible for liabilities created by substandard piping
methods andinstallation practices external to the chiller.
We trust your equipment will have a long and useful life. If
youshould have any questions, please contact our Customer
ServiceDepartment specifying the serial number and model number of
theunit as indicated on the nameplate.
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Receiving Inspection
Each unit is skid mounted and either boxed or crated prior to
ship-ment. Before accepting delivery, check the overall equipment
condi-tion for any visible damage. If damage is evident, it should
be prop-erly documented on the delivery receipt. Shipping damage is
theresponsibility of the carrier. In order to expedite payment for
dam-ages, it is important that proper procedures be followed and
recordskept. Photographs of damaged equipment are excellent for
yourrecords.
Once the unit is removed from the box or crate, it should be
inspectedfor hidden damage. Refrigerant lines can be susceptible to
damage intransit. Check for broken lines, oil leaks, damaged
controls, or anyother major component torn loose from its mounting
point.
Note: Any sign of damage should be recorded and a claim
filedimmediately with the shipping company. We will provide
assis-tance in preparation and filing of your claims, including
ar-ranging for an estimate and quotation on repairs; however,filing
the claim is the responsibility of the receiving party.
Rigging, Handling, and Locating Equipment
The units have a base platform on casters (two fixed and two
swivel)to provide in-plant mobility. Proper rigging methods must be
followedto prevent damage to components. Avoid impact loading
caused bysudden jerking when lifting or lowering the chiller. Use
pads whereabrasive surface contact is anticipated. The skid
supporting thechiller can be used for positioning the unit with a
fork lift.
As standard, these chillers are designed with NEMA-1
constructionsuitable for indoor use. Unless this unit was
specifically ordered withNEMA-4 construction for outdoor duty, it
should not be installed oreven stored in an outdoor location.
Serviceability was a primary concern when designing your
portablechiller. Removable panels permit easy access for periodic
mainte-nance or repair. Do not compromise this feature by locating
the chillerin an inaccessible area.
PRE-INSTALLATION
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!!!!! Air Cooled Chillers
In order to accommodate the air cooled condenser, the chiller
must belocated in a well ventilated area. A minimum of three feet
of clear-ance is required at both the condenser air inlet and
condenser airdischarge. Improper clearance or poor ventilation will
reduce thecooling capacity of the chiller and may cause high
refrigerant pressureproblems. The condenser air inlet temperature
should be maintainedabove 60F (15C) in order to avoid possible low
refrigerant pressuresafety trips during start-up.
If it is necessary to store the chiller in an unheated area when
not inuse, be sure that all water is drained or that an adequate
amount ofantifreeze is added to prevent freeze-up of the unit.
!!!!! Ethylene Glycol
Warning: Ethylene glycol is harmful or fatal if swallowedor
inhaled. Do not drink ethylene glycol solution. Ifswallowed, give
two glasses of water and induce vomiting.Call a physician
immediately. Avoid inhaling mist or hotvapors. If inhaled remove to
fresh air. Do not store inopen or unlabeled containers. Wash
thoroughly afterhandling. Solution can be poisonous to animals.
!!!!! Propylene Glycol
Warning: Although propylene glycol is not "toxic," asdefined by
regulations of the Consumer Product SafetyCommission, it is not
intended for human or animalconsumption.
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INSTALLATION
Electrical PowerNote: Main power to the chiller should remain
connected dur-ing off hours to energize the compressor's crankcase
heater.Disconnect main power only when servicing the chiller.
Thecrankcase heater should remain on at all times to ensureliquid
refrigerant does not accumulate in the compressorcrankcase.
A terminal block is provided for main power connection to the
electriccircuitry. An electrical knockout in the back panel for
1/2" conduit hasbeen provided for main power wiring. This knockout
may have to beenlarged for chillers with higher amp draws. All
components requir-ing electric power are prewired at the factory.
The main power sourceshould be connected to the terminal block
through an appropriatedisconnect switch. A separate lug for
grounding the unit is also pro-vided in the main control panel.
Note: All chillers should be properly grounded in compliancewith
local and national codes.
The control panel and safeties are interwired such that
connecting theappropriate power source to the main terminal block
energizes theentire electric circuitry of a chiller. A control
transformer has beenfactory wired to step down the incoming power
to the 115 volt controlpower.
Note: Electric power at the main disconnect should be shut
offbefore opening access panels for repair or maintenance.
Air Cooled Condenser (Air Cooled Chillers Only)
The performance of an air cooled condenser is dependent upon
main-taining the proper flow of air across the heat exchanger
surface. If theair flow is restricted at either the intake or
discharge, the coolingcapacity of the chiller will be reduced.
Reduced air flow may alsoresult in high refrigerant pressure
problems which will cause thechiller to shut down. Air flow can
also be reduced if the condensercoils become clogged with dirt. For
this reason, try to avoid locatingthe air intake where foreign
matter is likely to be drawn through thecondenser. If the condenser
does become clogged, it can be cleaned outusing compressed air.
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The standard rated cooling capacity of our air cooled chiller is
basedupon 95F (35C) ambient air temperature. If the air
temperatureentering the condenser is above 95F (35C), the capacity
will bereduced approximately 1% per 1F (0.5C). Entering air
temperaturesabove 110F (43C) may result in high refrigerant
pressure problemswhich would shut the unit down. For this reason,
it is very importantthat the chiller be located where the warm
discharge air will not berecirculated back into the condenser
inlet.
These chillers are designed for indoor usage with normal
indoorambient air temperature entering the condenser. Air
temperaturesbelow 60F (15C) entering the condenser may result in
low refrigera-tion pressure "cold start-up" problems.
Note: The condenser fans on these chillers are designed to
pullthe air through the condenser and discharge it out the side
ofthe unit. Ductwork should not be installed on the intake
ordischarge of these units.
Condenser Water Lines (Water Cooled Chillers Only)
The performance of the water cooled condenser is dependent on
main-taining the proper flow and temperature of water through the
heatexchanger. Insufficient water flow or high condenser water
supplytemperature will result in the reduction of cooling capacity
of thechiller. Extreme conditions will eventually result in the
chiller shut-ting down due to high refrigerant pressure.
Performance can also beaffected if the condenser is allowed to plug
up from contaminants inthe condenser water stream. In order to
reduce maintenance costsand chiller downtime, a water treatment
program is highly recom-mended for the condenser cooling water.
If the condenser does become plugged, contact our Customer
ServiceDepartment for assistance in the proper procedure for
cleaning outthe condenser.
The standard rated cooling capacity of a water cooled portable
chilleris based upon 85F (29C) condenser cooling water supply. With
85F(29C) condenser water supply, approximately 3 GPM of
condenserwater will be required per nominal ton of chilling
capacity. Thereshould be a minimum of 25 PSI differential between
the condenserwater supply pressure and the back-pressure on the
outlet of thecondenser. If the chiller has been equipped with a
condenser waterregulating valve, the condenser water flow will be
regulated to main-
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Required Condenser Water Flow
tain the refrigerant pressure at the factory set level. The
condenserwater regulating valve is standard on models AQ0W02
throughAQ1W15 and optional on all other models. The following chart
showscondenser water requirements and pipe sizing for the different
sizechillers. Please note that a condenser water supply
temperaturebelow 75F (24C) will not necessarily result in reduced
flowrequirements.
Chilled Water LinesAll chilled water piping should be adequately
insulated to preventcondensation. If water is allowed to condense
on the piping, the statechange of the water from gas to liquid will
result in a substantial heatload which becomes an additional burden
for the chiller.
Standard portable chillers have been designed for a nominal flow
of2.4 GPM per ton at nominal conditions. During normal
full-loadoperation with 50F (10C) coolant supplied to the process,
this nomi-nal flow rate will result in a 60F (15C) coolant returned
from theprocess. The nominal flow rate for each chiller is shown in
the Sug-gested Chilled Water Flow table. This table also provides
the maxi-mum flow rate for each chiller. The maximum flow rate
should not beexceeded unless the chiller was specifically ordered
to handle high-flow conditions.
If the process cannot handle the full nominal flow from the
chiller, theexcess water flow will simply bypass the process
through the bypassline inside the chiller. On air cooled models
AQ0A0H through AQ0A03
75F (24C) 85F (29C)Condenser Condenser Condenser
Water Water WaterFlow Flow Connection
Model # (GPM) (GPM) (FNPT)AQ0W02 3 5 1"AQ0W03 4 8 1"AQ0W05 8 15
1"AQ0W08 12 24 1"AQ0W10 16 31 1 1/2"AQ1W15 22 44 2"AQ1W20 29 57
2"AQ1W25 34 68 2 1/2"AQ1W30 40 79 2 1/2"AQ1W35 50 100 2 1/2"AQ1W40
60 120 3"
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Suggested Chilled Water Flow
and water cooled models AQ0W02 through AQ0W05, the bypass line
isfixed and requires no adjustment. On air cooled models
AQ0A06through AQ0A10 and water cooled models AQ0W08 through
AQ1W40,there is a cock valve on the bypass line which may require
adjustmentif the chiller is not operated using the nominal flow
rate. This valve islocated where the bypass line enters the
reservoir.
*A throttling valve on the process supplyline is provided to
adjust the flow rate toprocess.
The importance of properly sized piping between the chiller
andprocess cannot be overemphasized. See the Suggested Pipe
Sizingtable for proper pipe sizing. In general, run full size
piping out to theprocess and then reduce the pipe size to match the
connections on theprocess equipment. One of the most common causes
of unsatisfactorychiller performance is poorly designed piping.
Avoid unnecessarilylong lengths of hoses or quick disconnect
fittings which offer highresistance to water flow. When manifolds
are required for waterdistribution, they should be installed as
close to the use point aspossible. Provide flow balancing valves at
each machine to assureadequate water distribution in the entire
system. Typically, whenpiping is overhead with a total length of
90' or more, place a checkvalve in the supply line and trap the
return line (see Overhead PipingDiagram).
Nominal MaximumFlow Flow Rate Rate
Model # (GPM)* (GPM)*AQ0A0H 1 2AQ0A01 2 4AQ0A02 4 8AQ0A03 7
14AQ0A06 12 24AQ0A08 16 32AQ0A10 20 40AQ0W02 5 10AQ0W03 8 16AQ0W05
12 24AQ0W08 19 38AQ0W10 25 50AQ1W15 40 80AQ1W20 46 92AQ1W25 54
108AQ1W30 63 126AQ1W35 80 160AQ1W40 96 160
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Suggested Pipe Sizing
Overhead Piping
*Based on standardweight schedule 40 blackiron or PVC schedule
80pipes.
MaximumPipe Flow RateSize (GPM)*1/2" 23/4" 51" 10
1 1/4" 201 1/2" 30
2" 502 1/2" 90
3" 160
SPA-0121
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CHILLER START-UP
All chillers are fully tested prior to shipping. Readings of
voltage,amperage, compressor suction and discharge pressures, water
inletand outlet temperatures, water flow rates, etc., are recorded
to makesure that all system components are performing up to their
specifica-tions. Every unit is factory set to deliver chilled water
in accordancewith the standard operating specifications for that
particular chiller.Due to variables involved with different
applications and differentinstallations, minor adjustments may be
required during the initialstart-up to ensure proper operation.
The following start-up procedure should be followed in sequence.
Iftrouble is encountered in putting a chiller in operation, the
fault canusually be traced to one of the control or safety devices.
This outlinecan be used as a checklist for the initial start-up and
for subsequentstart-ups if the chiller is taken out of service for
a prolonged period oftime.
1. Assure the main power source is connected properly and that
itmatches the voltage shown on the nameplate of the unit.
Onceproper power connection and grounding have been confirmed,
turnthe main power on.
Note: The power must be on for 24 hours prior to starting
thecompressor to allow the crankcase heater to sufficientlyvaporize
any liquid refrigerant that may be present in thecompressor.
2. Check to make sure that all process chilled water piping
connec-tions are secure. Remove the top panel from the chiller and
thescrew cap from the top of the reservoir. Fill the reservoir with
theproper water or water/glycol solution.
3. (Water Cooled Units Only) Check the condenser water lines
tomake sure all connections are secure. Make sure sufficient
con-denser water flow and pressure are available (see Required
Con-denser Water Flow table), that the condenser water supply
isturned on, and that all shut-off valves are opened.
4. Check to make sure that all process chilled water piping
connec-tions are secure. Remove the top panel from the chiller and
thescrew cap from the top of the reservoir. (On the AQ1W35
andAQ1W40, use the fill port that extends through the top of
thecabinet.) Fill the reservoir with the proper water or
water/glycolsolution.
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Recommended Glycol Mixtures
Note: Water quality can vary greatly in different areas of
thecountry. Some water may require water treatment chemicals.A
corrosion inhibitor can be added if necessary; however, makesure
that it is compatible with ethylene glycol if there is glycolin the
system.
5. Make sure that the Freezestat is set appropriately for the
operat-ing conditions of the chiller. The Freezestat is located
inside themain electrical control panel. It should be set at 10F
(5C) belowthe minimum chilled water temperature setting that the
chillerwill be operated at. Be sure that there is sufficient glycol
in thesystem to handle at least 10F (5C) below the freezestat
setting.
All chillers are shipped from the factory with the Freezestat
set at40F (4C). This is done to protect against a possible
freeze-up ifno glycol has been added to the system. Once the proper
glycolsolution has been added, the freezestat can be adjusted to
theappropriate setting.
Note: Our warranty does not cover the evaporator fromfreezeups.
It is vital that the freezestat is set properly.
6. Turn on the control power by pressing the Power button.
Thedigital displays should now be illuminated.
7. Due to extreme temperatures during shipment, some of the
safe-ties may have tripped. If this is the case, manually reset
theFreezestat if necessary and then press the Reset button on
thefront panel.
8. Once all alarm conditions have been cleared, press the
Startbutton. At this time, the pump should start running. If the
con-troller is calling for cooling, the compressor may also start
at thistime.
PercentChilled Water Glycol byTemperature Volume50F (10C) not
required40F (4.4C) 20%30F (-1.1C) 20%20F (-6.6C) 25%
10F (-12.2C) 35%0F (-17.7C) 40%
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9. Check the rotation of the pump. If the pump is running
back-wards, switch two of the main power leads, after shutting off
thedisconnect switch. The pressure gauge on the back of the
unitshould be reading at least 20 PSI.
10. The coolant flow out to process can be adjusted by using the
cockvalve on the supply line just inside the chiller cabinet. If
theprocess does not create much of a pressure drop, the cock
valvemay have to be throttled in order to maintain the flow through
thechiller at an acceptable level. If the flow is more than double
thenominal flow rating, the cooling capacity of the chiller may
bereduced.
11. Temperature adjustment is the next step in putting the
chiller inoperation. Adjust the controller set point to the desired
tempera-ture. The chiller should now be controlling to that
temperature.Please note that if there is no load on the chiller,
the compressorwill cycle on and off causing swings in temperature
of up to 10F(5C).
12. Once proper flow and temperature are achieved, press the
Stopbutton and allow the water level in the tank to stabilize. Fill
thetank, replace the screw cap, and replace the top panel on
thecabinet.
The unit is now ready to be placed into service.
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Microprocessor Control Fault Logic
Alarm Reset button or Stop button on control board must be
pressed.Safety control must be manually reset before the controller
can be reset.Activates the alarm horn (if included) and closes the
alarms contacts (if included).
CONTROL PANEL OPERATION
Control Panel
The chiller includes a microprocessor controller designed to
performall control functions directly from the front panel. When a
button isdepressed, a click will be felt and the corresponding LED
will beenergized. Only one button should be pressed at a time.
The Microprocessor Control Fault Logic Table shown below
providesthe basic control fault logic for the microprocessor
controller. Thefollowing section details each of these diagnostics
and the controlbuttons.
Alarm Manual Remote Alarm Compressor Pump Reset Reset Alarm
Fault Indication Shutdown Shut Off Required Required ActivatedNo
Flow LED Yes Yes No No YesHigh Refrigerant Pressure LED Yes Yes Yes
No YesLow Refrigerant Pressure LED Yes No Yes No YesFreezestat LED
Yes No Yes Yes YesLow Oil Pressure LED Yes Yes Yes Yes YesOver Set
Point LED No No No No YesUnder Set Point LED Yes No Yes No YesLow
Water Level LED No No No No NoHigh Water Temperature LED No No No
No NoProbe Fault LED Yes Yes Yes No YesLow Power Pr OFF Yes Yes Yes
No YesPump Overload Err 126 Yes Yes Yes Yes YesCompressor Overload
Err 127 Yes Yes Yes No YesHigh Temperature Safety Err 128 Yes Yes
Yes No Yes
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Control Buttons
This unit was either shipped to display temperatures in F or C.
Dothe following to change the display.
1. With the power connected and the control power off, hold the
Stopbutton. While holding the Stop button press the Power
button.When the controller illuminates, release both buttons.
2. The To Process display will read "Unt". The Set Point display
willshow either "F" or "C" depending on the current display
unitsselected. If the current selected units are "F" press the down
key.If the current selected units are "C" press the up key.
3. The Set Point display should now indicate the desired
displayunits. Press the Start button to store the new selection
into thecontroller memory.
4. Press the Power button once to exit this function then press
thePower button again to restore controller power.
!!!!! Power
Depressing the Power button will switch the control power on or
off.Control power must be initiated before the chiller can be
started bythe Start button or by remote on/off contacts.
!!!!! Start
Depressing the Start button will start the pump and enable the
com-pressor. The compressor will start only if the microprocessor
is callingfor cooling because the actual To Process temperature is
higher thanthe Set Point temperature.
Note: Once the compressor has cycled off, it will not restart
fortwo minutes because of an internal anti-cycle time delay.
!!!!! Stop
Depressing the Stop button will shut off the compressor and
pump,and clear all fault signals.
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!!!!! Alarm Reset
Depressing the Alarm Reset button will reset any fault indicator
thathas been activated on the control board. This includes any
LEDindicators or alarm codes. The Freezestat, Low Oil Pressure,
andPump Overload require a mechanical safety to be manually
resetbefore the control board can be reset.
Note: If the condition still exists that originally caused
thealarm indication, the alarm may be reactivated as soon as it
isreset.
!!!!! Alarm Silence
The Alarm Silence button is not functional unless the Alarm
Hornoption or the Remote Alarm contacts option has been purchased.
Ifthe Alarm Horn option has been purchased, depressing the
AlarmSilence button will disable the horn. The horn will not
reactivate untilthe alarm has been reset and a subsequent alarm has
been triggered.If the Remote Alarm contacts option has been
purchased, depressingthe Alarm Silence button will reopen the
contacts which were closedwhen the alarm occurred. The contacts
will not close again until thealarm has been reset and a subsequent
alarm has been triggered.
!!!!! Lower Set Point Temperature
Each time that the ! button is depressed momentarily, the Set
Pointtemperature will be decreased by 1F (or 1C). If the ! is held
down,the Set Point temperature will continue to decrease until the
button isreleased.
!!!!! Raise Set Point Temperature
Each time that the # button is depressed momentarily, the Set
Pointtemperature will be increased by 1F (or 1C). If the # is held
down,the Set Point temperature will continue to increase until the
button isreleased.
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Diagnostic LEDs
!!!!! No Flow
The No Flow LED will be illuminated if the flow through the
chiller isbelow the preset acceptable level. When the Start button
is depressed,this safety is defeated for a period of 20 seconds in
order for the pumpto establish flow. The No Flow LED may remain
illuminated duringthis 20 second period. This safety will shut off
the pump and thecompressor. If the chiller has been shut down by
the No Flow safety,the Start button must be depressed in order to
restart the pump andreset the 20 second time delay.
!!!!! High Refrigerant Pressure
If the compressor discharge refrigerant pressure exceeds the
settingon the high refrigerant pressure safety, the compressor and
pump willshut off and the High Refrigerant Pressure LED will be
illuminated.The High Refrigerant Pressure fault can be reset by
pressing theAlarm Reset button, as long as the refrigerant pressure
has droppedback down below the safetys cutout level.
!!!!! Low Refrigerant Pressure
If the compressor suction pressure drops below the setting on
the lowrefrigerant pressure safety, the compressor will shut off,
the pump willremain running, and the Low Refrigerant Pressure LED
will be illu-minated. The Low Refrigerant Pressure fault can be
reset by pressingthe Alarm Reset button, as long as the refrigerant
pressure has risenback up above the safetys cutout level.
!!!!! Freezestat
If the coolant temperature being delivered to the process drops
belowthe setting on the Freezestat, the compressor will shut off,
the pumpwill remain running, and the Freezestat LED will be
illuminated. TheFreezestat should be set 10F (5C) above the
freezing point of theglycol solution and 10F (5C) below the minimum
operating tempera-ture. The Freezestat is factory set at 40F (4C).
In order to reset theFreezestat fault, press the Alarm Reset button
after resetting themechanical thermostat (labeled Freezestat)
inside the electricalenclosure.
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!!!!! Low Oil Pressure
Only chillers with a semi-hermetic compressor are equipped with
aLow Oil Pressure safety switch. On these units, if the oil
pressure inthe compressor crankcase drops below the factory-set
level on the oilpressure switch, the compressor and pump will shut
off, and the LowOil Pressure LED will be illuminated. In order to
reset the Low OilPressure fault, press the Alarm Reset button after
resetting the me-chanical pressure switch located inside of the
cabinet near thecompressor.
!!!!! Over Set Point
The Over Set Point LED will be illuminated if the To Process
tempera-ture exceeds the Set Point temperature by more than 5F (or
3C).This fault causes only an alarm indication (horn and/or remote
con-tacts), and the chiller will continue to operate. Although the
Over SetPoint LED will turn on immediately whenever the temperature
is outof range, the alarm relay is disabled for 30 minutes after
start-up orafter a change in set point. The alarm will
automatically clear whenthe temperature comes back into range.
!!!!! Under Set Point
The Under Set Point LED will be illuminated if the To Process
tem-perature drops below the Set Point temperature by more than 10F
(or5C). This fault will shut off the compressor, but the pump will
con-tinue to run. Although the Under Set Point LED will turn on
immedi-ately whenever the temperature is out range, the alarm relay
isdisabled for 30 minutes after start-up or after a change in set
point.This fault can be reset by pressing the Alarm Reset
button.
!!!!! Pump On
The Pump On LED will be illuminated whenever the pump is
run-ning. If the pump is shut off due to a safety, the Pump On LED
willturn off. The Start button must be pressed in order to restart
thepump.
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!!!!! Compressor On
The Compressor On LED will be illuminated whenever the
compres-sor is running. The Compressor On LED will cycle on and off
with thecompressor. The compressor will not come on unless the pump
isalready running and the To Process temperature is above the
SetPoint temperature.
Note: During normal operation, the compressor may cycle onand
off. An internal anti-cycle time delay will not allow thecompressor
to restart for two minutes after it has cycled off.
!!!!! Partial Load
The Partial Load LED will be illuminated whenever the
microproces-sor energizes the hot gas bypass solenoid valve. This
valve is cycled inorder for the chiller to maintain a constant To
Process temperatureeven when there is only a partial load. The
longer that this LED stayson, the more unused excess capacity is
available from the chiller. Ifthe Partial Load LED stays off, the
chiller is fully loaded by the heatfrom the process. If the Partial
Load LED stays on, the chiller has avery small load on it from the
process. If this low load conditionpersists, the To Process
temperature may begin to drop below the SetPoint temperature, and
when it reaches 7F (or 4C) below the SetPoint temperature, the
compressor will cycle off. The compressor willcome back on when the
To Process temperature rises back up to theSet Point temperature
and the anti-cycle two minute time delay relayhas timed out.
!!!!! Water Make-Up
The Water Make-Up LED is only functional if the Water
Make-Upoption is purchased with the chiller. When the water level
in thereservoir drops below the lower limit of the float switch,
the watermake-up solenoid valve is opened and the Water Make-Up LED
isilluminated. When the water level rises to the upper limit of the
floatswitch, the water make-up solenoid is closed and the Water
Make-UpLED turns off. The microprocessor will also close the water
make-upsolenoid valve if it has been open for a period of ten
minutes. This isdone to help prevent further problems if a water
leak has developed inthe system. If this occurs, the Water Make-Up
LED will turn off, butthe Low Water Level LED will remain
illuminated.
!
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!!!!! Low Water Level
The Low Water Level LED is only functional if either the Low
WaterLevel option or the Water Make-Up option is purchased. When
thewater level in the reservoir drops below the lower limit of the
floatswitch, the Low Water Level LED is illuminated. When the
waterlevel rises to the upper limit of the float switch, the Low
Water LevelLED will shut off.
!!!!! High Water Temperature
The High Water Temperature LED will be illuminated if the To
Pro-cess temperature rises more than 10F (or 5C) above the Set
Pointtemperature. The High Water Temperature LED will turn off
whenthe water temperature drops back within 10F (or 5C). This
faultwill not stop operation of the chiller.
!!!!! Probe Fault
The Probe Fault LED will illuminate if the signal from the
thermo-couple is out of tolerance. This fault will also shut off
the compressorand the pump. It can be reset by pressing the Alarm
Reset button.
Diagnostic Error Codes
Several different error codes may be displayed on the digital
readoutslabeled To Process and Set Point. Most of the possible
error codesindicate some type of failure in the microprocessor
controller. Thereare also four specific faults listed below which
show up as error codes.If there is an error code other than these
four, try to reset the chillerby shutting the power off and then
turning it back on. If this does notwork, make a note of the error
code and contact the Customer ServiceDepartment for further
assistance.
!!!!! Pr Off
If the chiller is running and main power is discontinued or
drops morethan 10% below the normal operating voltage, the unit
will shut downand the Pr OFF fault will be indicated on the digital
displays. Thisfault condition can be cleared by pressing the Stop
button.
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!!!!! Err 126
The Err 126 fault code will be indicated on the digital displays
if thepump has gone off due to the pump overload. In order to reset
thisfault, press the Alarm Reset button after resetting the pump
overloadinside the electrical enclosure.
!!!!! Err 127
Some units equipped with a semi-hermetic compressor include
thisfunction. The Err 127 fault code will be indicated on the
digital dis-plays if the compressor has gone off due to the
internal compressorthermal overload. This fault will also shut off
the pump. The thermaloverload will automatically reset when the
compressor motor windingtemperature drops back into the normal
operating range. Once thisoccurs, the fault can be reset by
pressing the Alarm Reset button.
Note: Units equipped with a scroll compressor will requiremanual
reset of the compressor motor overload module.
!!!!! Err 128
The Err 128 fault code will be indicated on the digital displays
if thechiller has been shut off due to the high temperature safety.
Thissafety will shut off both the pump and compressor. This safety
istriggered if the To Process temperature rises more than 10F (or
5C)above the maximum operating temperature for that particular
chiller.The maximum operating temperature for each chiller is noted
on thenameplate. The To Process temperature must be over the limit
forthree minutes before this safety will be triggered, and the
fault isdefeated for a period of 30 minutes from the time the Start
button ispressed or the Set Point temperature is changed. This
fault can bereset by pressing the Alarm Reset button.
Control Options
!!!!! Return Water Temperature Display
If the Return Water temperature display option is purchased, the
ToProcess digital display can be used to view To Process
temperature orReturn Water temperature. To view the Return Water
temperature,hold down the ! and # buttons simultaneously. Once the
buttons arereleased, the display will return to To Process
temperature.
!
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!!!!! Low Coolant Level Indicating Light
If the Low Coolant Level indicating light option has been
included,this light on the control panel will be illuminated if the
coolant levelin the reservoir drops below the preset level. The
light will turn backoff once the coolant level has been restored to
the proper operatinglevel. This light is simply an indication that
coolant should be addedto the reservoir in the near future. The
chiller will continue to operatenormally when this light is on.
!!!!! Remote On/Off Contacts
If the Remote On/Off contacts are included, the chiller can be
turnedon and off via a remote contact closure. Two contacts are
provided onthe terminal block in the control panel. These contacts
are to be wiredto a remote contact closure device. Switching the
contacts from opento closed simulates pressing the Start button on
the control panel.Switching the contacts from closed to open
simulates pressing theStop button. Please note that the Remote
On/Off contacts are notfunctional until the controls have been
energized by pressing thePower button. This option also includes a
remote/local toggle switchwhich allows the operator to disable the
remote contacts for safetypurposes while the unit is being
serviced.
Note: Do not introduce any external voltage to these contacts,as
this will result in damage to the microprocessor, which willnot be
covered by the warranty.
!!!!! Remote Alarm Contacts
If the Remote Alarm contacts are included, a set of contacts
will beclosed when there is an alarm condition. Refer to the
MicroprocessorControl Fault Logic table to determine which faults
will trigger theRemote Alarm contacts. The contacts can be reopened
by clearing thefault or by pressing the Alarm Silence button.
!!!!! Alarm Horn
If the Alarm Horn option is purchased, the control panel will be
fittedwith an alarm horn which will be activated by certain faults.
Refer-ence the Microprocessor Control Fault Logic table to
determine whichfaults will trigger the horn. The horn can be
silenced by clearing the
!
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Page 24
fault or by pressing the Alarm Silence button. If this option is
se-lected in conjunction with the remote control panel, the horn
will bemounted on the chiller and not the panel.
!!!!! Remote Control Panel
With the Remote Control Panel option, the display board is
mountedin a separate NEMA-1 enclosure. The controller and the
chiller areconnected by a factory wired cable 50 feet long. All
control functionsare available to the operator at the location of
the remote panel andno control functions are available at the
location of the chiller.
!!!!! SPI Communications
If the SPI Communications option is included, an RS-485
communica-tion port will be located below the control panel on the
front of thechiller. The serial communications will be multi-drop,
half duplex, SPI3.01 compatible. This option allows the chiller to
communicate withanother piece of equipment that also has SPI
protocol capabilities.The following SPI communications are
supported by themicroprocessor.
$ Process Temperature Setpoint$ High Deviation$ Low Deviation$
Process Status$ To Process Temperature
The microprocessor is designed to accept inputs and deliver
outputsaccording to SPI protocol. There must also be a computer or
anotherpiece of equipment which is equipped with the SPI protocol
in orderfor the communications from the chiller to be of any use.
The pro-gramming of this computer and/or other equipment is not the
respon-sibility of the manufacturer.
Note: The manufacturer is not responsible for SPI
protocolprogramming beyond what is included in the
microprocessorcontroller.
When the SPI option is included, there is a second set of DIP
switchesincluded on the back of the main control panel. This set of
DIPswitches is labeled COMM. All DIP switch adjustments that
followare to be made on the COMM set. Do not adjust any DIP
switches onthe CONFIG set.
!
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Note: All DIP switch changes must be made with
powerdisconnected.
In order to activate the SPI protocol, DIP switch #8 must be set
to theOn position. To deactivate the SPI communication, set DIP
switch#8 to the Off position.
If more than one piece of equipment is going to be on the same
com-munications network, the base address will have to be changed
so thateach unit has a unique address. This is done by changing one
or moreof the DIP switches to the Off position. The base address is
32decimal. Changing these switches causes the following
addresschange.
DIP Switch 1 OFF Add one to base addressDIP Switch 2 OFF Add two
to base addressDIP Switch 3 OFF Add four to base addressDIP Switch
4 OFF Add eight to base addressDIP Switch 5 OFF Add sixteen to base
address
The BAUD rate can be adjusted to the appropriate setting by
using thefollowing chart.
BAUD Rate DIP Switch #6 DIP Switch #71,200 ON ON2,400 OFF
ON4,800 ON OFF9,600 OFF OFF
!
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CHILLER OPERATION
The following diagram illustrates the basic operation of a water
cooledportable chiller. There is a brief description of the coolant
circuit andthe refrigerant circuit. Keep in mind that this drawing
is general innature and that some of the components and piping may
changedepending on which options have been selected.
Typical Piping Schematic
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Page 27
Coolant Circuit
The pump draws coolant from the reservoir and circulates it
throughthe evaporator. It is in the evaporator where the heat is
transferredfrom the coolant to the refrigerant. The temperature of
the coolantbeing delivered to the process is controlled by
adjusting the amount ofheat transferred in the evaporator.
After leaving the evaporator, the coolant passes through a
manifoldwhich includes a freezestat sensing bulb, flow switch (or
pressureswitch), thermocouple and process supply throttling valve.
Thefreezestat sensing bulb, flow switch and pressure switch are
safetycontrols that are connected to the microprocessor. The
thermocouplesenses the temperature of the coolant being delivered
to process andcommunicates this temperature to the microprocessor.
The processsupply throttling valve can be used to adjust the flow
out to process.Opening this valve will increase the flow to process
while closing itwill result in a reduction of flow.
This manifold is connected directly to the process water supply
con-nection on the back of the chiller. Once the coolant passes
throughthis manifold, it is delivered out to process where it picks
up theprocess heat before returning to the process water return
connection.From this connection, the coolant returns directly to
the reservoirwhere the whole sequence starts over.
A small coolant bypass line tees off of the manifold between the
ther-mocouple and the supply throttling valve. This line allows the
chillerto operate with sufficient flow through the evaporator even
if the flowis restricted or completely shut off through the
process. On air cooledmodels AQ0A0H through AQ0A03 and water cooled
models AQ0W02through AQ0W05 chillers, the bypass is a small copper
line runningfrom the process supply manifold to the process return
line. On aircooled models AQ0A06 through AQ0A10 and water cooled
modelsAQ0W08 through AQ1W40, the bypass is a hose that runs from
theprocess supply manifold directly back into the reservoir. There
is acock valve located in this line right where it connects to the
reservoir.This valve can be adjusted depending on how much flow is
required bythe process.
Note: Closing this valve off too far may result in a
situationthat could damage components in the chiller. The main
pur-pose of the bypass line is to avoid deadheading of the pump
andreduce the possibility of a freeze-up.
!
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Page 28
Refrigerant Circuit
The heat that is transferred in the evaporator from the coolant
to therefrigerant is used to change the state of the refrigerant
from a liquidto a gas. After leaving the evaporator, the
refrigerant passes throughthe suction accumulator. The purpose of
the suction accumulator is totrap any liquid refrigerant that may
exit the evaporator during start-up. The refrigerant gas passes
through to the compressor. Thetrapped liquid in the suction
accumulator will eventually boil off andmove on to the
compressor.
The compressor is the heart of the refrigeration circuit. It
takes thecool, low pressure gas entering the compressor and
compresses itwhich creates the hot, high pressure gas that exits
the compressor.Since the compressor is not 100% efficient, some
extra heat is added tothe refrigerant as it is being
compressed.
The hot, high pressure gas that exits the compressor is
delivered tothe condenser. In the condenser, the heat is
transferred from therefrigerant into the air stream or water stream
that is passingthrough in the opposite direction. As the heat is
transferred, therefrigerant changes from a gas to a liquid. The
condenser has beensized to remove the heat from the process load
and the heat that wasadded by the compressor.
After leaving the condenser, the liquid refrigerant passes
through thereceiver (air cooled units only), the filter drier and
sight glass. Thefilter drier filters out any particles and/or
moisture from the refriger-ant. The sight glass is used to monitor
the stream of liquid refriger-ant. The liquid refrigerant then
passes through the thermal expan-sion valve (TXV) which meters the
flow into the evaporator where theprocess starts all over
again.
Capacity and temperature control is accomplished with a hot
gasbypass system on these chillers. If the chiller is catering to a
partialload from the process, the coolant supply temperature would
normallytend to drop. The microprocessor senses this drop in
temperature, andopens the hot gas bypass solenoid valve. When this
valve is open,some of the hot compressor discharge gas is directed
to the inlet of theevaporator instead of going through the
condenser. This puts anadditional heat load on the evaporator which
brings the coolant tem-perature back up to set point. With PID
control from the microproces-sor and the solenoid cycling as much
as once every ten seconds, cool-ant temperature is usually
controlled within 1F (0.5C) of set pointeven with loads as low as
10% - 25% of full capacity.
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Page 29
If the process heat load is extremely low, or even nonexistent,
the hotgas bypass system may not be able to put enough of a false
load on theevaporator, and the coolant temperature will begin to
drop. When thecoolant temperature drops to 7F (4C) below the set
point tempera-ture, the controller will shut the compressor off.
When the coolanttemperature rises back to the set point
temperature, the compressorcomes back on.
The compressor will remain off for at least two minutes to
preventshort cycling.
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Page 30
CHILLER CONSTRUCTION
Refrigeration Components
!!!!! Compressor
HermeticIf the model number of the chiller begins with AQ0, then
the chiller isequipped with a hermetically sealed compressor. Both
the compressorand the motor are encased together in the enclosure.
Inside thecasing, the compressor is spring mounted which extends
compressorlife and provides quiet operation. The motor windings are
cooled bythe cool refrigerant suction gas, and there is an internal
thermaloverload to protect the windings from overheating. The
compressoralso includes a crankcase heater which will boil off any
liquid refriger-ant that may have migrated into the compressor
crankcase while thechiller was shut off. The compressor is
lubricated with oil that travelsthroughout the system with the
refrigerant.
Semi-HermeticIf the model number of the chiller begins with AQ1,
then the chiller isequipped with a semi-hermetic compressor. A
semi-hermetic compres-sor has all of the features of the hermetic
compressor except that thesemi-hermetic compressor has removable
heads so that it can betaken apart to be serviced or rebuilt. The
semi-hermetic compressor isnot internally spring mounted like the
hermetic compressor, so ittends to run a little louder.
ScrollIf the model number of the chiller begins with AQ2, then
the chiller isequipped with a scroll compressor(s). Both the
compressor and themotor are encased together and solidly mounted in
the enclosure. Thecompressor is unidirectional and will only pump
refrigerant whenproperly phased. The motor windings are cooled by
the cool refriger-ant suctions gas, and there is an internal
thermal overload to protectthe windings from overheating. The
compressor is lubricated with oilthat travels throughout the system
with the refrigerant.
!!!!! Air Cooled Condenser (Air Cooled Units Only)
The air cooled condenser is constructed of heavy gauge copper
tubingand aluminum fins for maximum heat transfer capabilities.
Thecondensers have been generously sized so that chillers can
operatewith full cooling capacities with ambient air temperatures
of up to95F (35C). With higher ambient temperatures, the chiller
will lose
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Page 31
approximately 1% of its cooling capacity per 1F (0.5C) above
95F(35C). The chiller should be able to operate with ambient
tempera-tures of up to 110F (43C).
The fan(s) draw the air flow through the condenser and blows
thewarm discharge air through the chiller cabinet and out the other
side.The fan(s) are designed to draw sufficient air flow through
the chilleras long as there are no obstructions. The fan(s) are not
capable ofdrawing air in through ductwork on the intake or
discharging airthrough ductwork on the exhaust. The discharge air
will be approxi-mately 35F (20C) warmer than the intake air.
!!!!! Water Cooled Condenser (Water Cooled Units Only)
There are two different types of water-cooled condensers used in
thesechillers. Models AQ0W02 through AQ0W05 use a tube-in-tube
stylecondenser, while models AQ0W08 through AQ1W40 rely on a
shell-and-tube type condenser.
The tube-in-tube condensers have a steel outer tube with a
copperinner tube. The refrigerant passes between the steel and the
copper,while the condenser water flows through the copper tube in
the oppo-site direction from the refrigerant.
The shell-and-tube condensers are constructed with a steel
shell,removable cast iron end bells, and a bundle of copper tubes.
Thecondenser water passes through the copper tubes, while the
refriger-ant passes in the opposite direction around the tubes.
!!!!! Condenser Water Regulating Valve (Water Cooled Units
Only)
A condenser water regulating valve is provided as standard on
modelsAQ0W02 through AQ1W15 chillers. On models AQ1W20
throughAQ1W40 it is available as an option. This valve is located
in thecondenser water piping at the inlet of the condenser. It
regulates theflow of water through the condenser in order to
maintain the high-siderefrigerant pressure. This valve is set at
the factory and should onlybe adjusted by a qualified refrigeration
technician. This valve onlypasses as much water as is required to
maintain the refrigerantpressure, so less water will be required if
the water temperature islower than the design 85F (29C).
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Page 32
Note: The condenser water regulating valve may not
completelyshut-off water flow when the chiller is not operating. If
flowmust be completely stopped for any reason, a shut-off valvemust
be used. Make sure the shut-off valve is reopened beforerestarting
the chiller.
!!!!! Evaporator
There are three different types of evaporators used in these
chillers.Air cooled models AQ0A0H through AQ0A03 and water cooled
modelsAQ0W02 and AQ0W03 use a tube-in-tube style evaporator. Air
cooledmodels AQ0A06 through AQ0A10 and water cooled models
AQ0W05through AQ1W30 use a brazed plate style evaporator. Water
cooledmodels AQ1W35 and AQ1W40 use a shell-and-tube evaporator.
The tube-in-tube evaporators have a steel outer tube with a
copperinner tube. The refrigerant passes between the steel and the
copper,while the coolant flows through the copper tube in the
opposite direc-tion from the refrigerant.
The brazed plate evaporators are constructed with stainless
steelplates and copper brazing. The refrigerant passes between
everyother set of plates, while the coolant flows on the other side
of theplates in the opposite direction.
The shell-and-tube evaporators are constructed with a steel
shellaround a bundle of copper tubes. The refrigerant passes
through thecopper tubes, while the coolant passes in the opposite
direction aroundthe tubes.
!!!!! Thermostatic Expansion Valve (TXV)
The TXV separates the refrigerant high pressure/temperature on
thecondenser side from the refrigerant low pressure/temperature on
theevaporator side. The TXV meters the amount of refrigerant into
theevaporator in the precise quantity to match the process load.
Thisvalve uses a pressure limiting design and has been factory set
forproper operation. Only a trained refrigeration service
technicianshould adjust this valve.
The difference between the saturated evaporative temperature
andthe suction line temperature at the TXV sensor bulb location is
calledsuperheat. The superheat is factory set for 10F to 12F (5C to
6C)and should never exceed 15F (8C).
!
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Page 33
!!!!! Refrigerant Sight Glass
The refrigerant sight glass is located in the liquid line
immediatelyahead of the expansion valve. It allows the operator or
service techni-cian to observe the flow of liquid refrigerant.
Prolonged periods offoaming in the sight glass may indicate a low
refrigerant condition ora restriction in the liquid line.
Note: Occasional bubbling in the sight glass may occur at atime
when load conditions are changing and the thermostaticexpansion
valve is adjusting to the new conditions. This mo-mentary
occurrence is a result of normal chiller operation.
The sight glass can also be used to check if there is moisture
in therefrigeration system. If there is moisture in the system, the
green dotin the center of the sight glass will turn yellow. If this
occurs, thechiller should be serviced immediately.
!!!!! Refrigerant Filter Drier
The filter drier is located in the liquid line between the
condenser (orreceiver if the chiller is air cooled) and the
refrigerant sight glass. Itis designed to remove any moisture
and/or foreign matter that mayhave gotten into the refrigerant
stream. Moisture and foreign mattercan cause serious damage to the
components of a refrigeration system.For this reason, it is
important that the chiller be equipped with aclean filter drier.
Replace the filter drier any time the followingconditions
occur.
1. The refrigeration system is opened to the atmosphere for
repairsor maintenance.
2. Moisture is indicated in the sight glass (the green dot has
changedto yellow).
3. An excessive pressure drop develops across the filter drier.
This isindicated by a significant temperature difference between
thefilter inlet and outlet.
!!!!! Liquid Receiver (Air Cooled Units Only)
The receiver is a refrigerant vessel which holds excess liquid
refriger-ant that may not be required in the system under certain
operating
!
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Page 34
conditions. It is located in the liquid line directly after the
condenser.The receiver is supplied with a shut-off valve on the
outlet whichenable pump-down of the refrigeration circuit for
servicing.
!!!!! Suction Accumulator
The suction accumulator is the refrigerant vessel located in the
suc-tion line between the evaporator and the compressor. The
purpose ofthe suction accumulator is to trap any liquid refrigerant
before it canenter the compressor. The refrigerant gas is allowed
to pass through,while the liquid will remain in the bottom of the
vessel. The trappedliquid will eventually boil off and move on to
the compressor.
!!!!! Hot Gas Bypass Valve
This valve is located in the refrigerant line that runs from the
com-pressor discharge to the evaporator inlet. It is designed to
provide thecompressor with a continuous full load even when the
chiller is cater-ing to a partial load from the process. This is
accomplished by direct-ing some of the hot compressor discharge gas
directly back into theevaporator instead of going through the
condenser. The amount of hotgas that is used is controlled by the
microprocessor controller. Elimi-nating cycling of the compressor
is extremely desirable as it signifi-cantly extends its lifetime
expectancy.
Wet-Side Components
!!!!! Reservoir
On chillers up to 30 HP, the coolant reservoir is mounted on top
of theshelf in the chiller and is easily accessible by removing the
top panel.The reservoir is made of polyethylene and is fully
insulated. A slothas been made in the insulation so that the
coolant level can be ob-served without removing any panels. There
is a six inch screw cap onthe top of the reservoir that can be used
for filling and cleaning. Thereis a small hole in this cap so that
air can vent to the atmosphere.
Note: These reservoirs are not designed to be
pressurized.Modifications to the chiller that would result in
pressurizationof the reservoir will void the warranty.!
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Page 35
Air cooled models AQ0A0H through AQ0A03 and water cooled
modelsAQ0W02 through AQ0W05 are equipped with an eight gallon
reser-voir, air cooled models AQ0A06 through AQ0A10 have a 20
gallonreservoir, while water cooled models AQ0W08 through AQ1W30
havea 45 gallon reservoir. During chiller operation, these
reservoirs shouldbe at least half full. For most installations,
these tanks have sufficientcapacity to handle the coolant that
drains back from the piping whenthe chiller is shut off. For
overhead piping runs of more than 50 feet,special precautions will
have to be made during installation. Seedetails on Overhead Piping
diagram for overhead piping installations.
Water cooled models AQ1W35 and AQ1W40 are equipped with a
40gallon cylindrical galvanized steel reservoir mounted inside
thecabinetry above the pump. This reservoir is filled using the
fill-portthat extends through the top of the cabinet. There is a
sight glasslocated at one end of the tank. These tanks cannot be
pressurized,and it is very likely that overhead piping will require
the specialprecautions illustrated on the Overhead Piping
Diagram.
!!!!! Coolant Pump
The close-coupled centrifugal pump is equipped with a
mechanicalseal. The 1 HP pumps are constructed of bronze, while all
othersizes are bronze-fitted cast iron construction. Each pump is
factorytested for the specified operating conditions. The ODP motor
meetsNEMA specifications and industry standards.
!!!!! Pressure Gauge
A pressure gauge is mounted on the back panel of the chiller.
Thisgauge displays the pressure of the coolant at the discharge of
thepump. It can be used to determine the approximate point on
thepump curve in which the pump is operating.
!!!!! Process Supply Throttling Valve
This cock valve is located just inside the cabinet on the
process supplyline. It can be accessed by removing the top panel of
the chiller. Thepurpose of this valve is to enable the operator to
reduce the coolantflow out to process. It is possible with certain
applications that thisvalve will need to be closed slightly in
order to keep the flow throughthe evaporator within the design
parameters. For most applications,this valve should be wide
open.
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Page 36
Note: Although partially closing this valve will raise the
pres-sure reading on the pressure gauge, the pressure being
deliv-ered to the process will actually be reduced. Throttling
thisvalve will always reduce the flow out to process.
Operating and Safety Controls
! ! ! ! ! Fan Cycling Controls (Air Cooled Units Only)
The fan cycling controls are designed to turn the condenser fans
onand off in order to maintain a constant compressor discharge
refriger-ant pressure. During normal operation, the fans will cycle
on and offbased upon the process heat load and ambient air
conditions.
Note: It is possible that a condenser fan will continue to
oper-ate after the chiller has been shut-off. This fan will
automati-cally shut off as soon as the refrigerant pressure drops
belowthe preset level on the fan cycling control.
!!!!! High Refrigerant Pressure Switch
The high refrigerant pressure switch is designed to limit the
compres-sor discharge pressure so that it stays within the design
parameters ofthe compressor. The switch is located inside the small
electricalenclosure next to the compressor. The switch can be reset
by pressingthe Alarm Reset button on the control panel. The setting
on thisswitch is not adjustable on most models. If it is
adjustable, no changesshould be made without prior approval from
the factory.
!!!!! Low Refrigerant Pressure Switch
The low refrigerant pressure switch is designed to limit the
compres-sor suction pressure so that it stays within the design
parameters ofthe compressor. The switch is located in the small
electrical enclosurenext to the compressor. The switch can be reset
by pressing the AlarmReset button on the control panel. The setting
on this switch is ad-justable; however, no changes should be made
to the setting withoutprior approval from the factory.
!
!
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Page 37
!!!!! Freezestat
The freezestat control is a mechanical thermostat which senses
thecoolant temperature separately from the microprocessor
controller.This safety is designed to limit the temperature of the
coolant leavingthe evaporator and prevent any possible freeze-up
situations. Thiscontrol should be set 10F (5C) below the minimum
coolant supplytemperature, and there should be a sufficient glycol
concentration for10F (5C) below the freezestat setting. Manual
reset is required.
Note: It is critical that the freezestat is set properly and
thatthere is sufficient glycol in the system to correspond with
thefreezestat setting. Freeze-ups can cause extensive damage
toseveral components in the chiller, and the warranty does notcover
repairs required due to a freeze-up.
!!!!! Coolant Pressure Switch
Air cooled models AQ0A0H through AQ0A03 and water cooled
modelsAQ0W02 through AQ0W05 are equipped with a coolant
pressureswitch. This switch is located in the process supply piping
manifold.It is designed to shut the unit down if there is
insufficient coolantpressure. This switch is adjustable; however,
the setting should not bechanged without prior authorization from
the factory. If the chillershuts down due to low coolant pressure,
it can be restarted by press-ing the Start button on the control
panel. This switch is disabled fortwenty seconds after the Start
button is pressed so that the pump candevelop pressure and make the
switch.
!!!!! Coolant Flow Switch
Air cooled models AQ0A06 through AQ0A10 and water cooled
modelsAQ0W08 through AQ1W40 are equipped with a coolant flow
switch.This switch is located in the piping directly before the
evaporatorinlet. It is designed to shut the unit down if there is
insufficientcoolant flow through the evaporator. The switch is
adjustable; how-ever, no adjustments should be made without prior
approval from thefactory. If the chiller shuts down due to low
coolant flow, it can berestarted by pressing the Start button on
the control panel. Thisswitch is disabled for 20 seconds after the
Start button is pressed sothat the pump can develop flow and make
the switch.
!
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Page 38
STANDARD OPTIONS
There are many different combinations of options available on
por-table chillers. Many special options are provided so that the
chillercan meet the special requirements of a particular process.
It is notpractical to include all of the special options in this
manual; therefore,in instances where these options have been
included, it may be neces-sary to refer to separate documentation
for the specifics of the specialfeatures. The following are the
most common standard options.
!!!!! Automatic Water Make-Up
With this option, a water supply can be connected to the chiller
so thatthe water level in the reservoir is automatically
maintained. Whenthe water level in the reservoir drops below the
low-level on the floatswitch, a solenoid valve will be opened to
allow fresh water into thesystem. When the water level reaches the
high-level on the floatswitch, the solenoid valve is closed.
Note: This option is not normally recommended for systemsthat
depend on a glycol solution to prevent freeze-ups. Auto-matic water
make-up may cause reduction of the glycol concen-tration, which may
result in a freeze-up.
!!!!! Automatic Water Bypass Valve
With this option, the valve in the bypass line is upgraded to an
auto-matic pressure regulating valve. This valve will automatically
adjustthe flow through the bypass line in order to maintain a
maximumwater pressure to process. This constant pressure will be
maintainedeven with changing flow conditions from the process. The
pressuresetting on this valve can be changed by adjusting the
tension of thespring within the valve. To raise the pressure, turn
the stem of thevalve in the clockwise direction, and turn the stem
counterclockwise tolower the pressure.
Note: Caution should be taken when setting this valve on
unitsthat are equipped with a pressure switch instead of a
flowswitch (1/2 HP through 5 HP units). Setting the pressure
toohigh may result in deadheading of the pump and freezing up ofthe
evaporator. Each unit leaves the factory with the valve
setproperly.
!
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Page 39
!!!!! Crankcase Pressure Regulating Valve
On a standard portable chiller the To Process temperature can be
setanywhere in the range from 30F (-1C) to 60F (16C). With
thisoption included, the To Process temperature can be set up to
75F(24C). The microprocessor controller will limit the upper To
Processset point to either 60F (16C) or 75F (24C) depending on
whether ornot this option is included.
The purpose of this valve is to limit the refrigerant suction
pressuregoing to the compressor. Higher To Process coolant
temperature willresult in a higher suction gas pressure. Higher
suction pressurecauses the compressor to do more work which will
eventually causethe motor to fail. The CPR valve brings the suction
gas temperatureback to an acceptable level for the compressor.
!!!!! Nonferrous Construction
Standard chillers have several components in contact with the
coolantthat are made of mild steel. This is acceptable for most
applications;however, for applications that require extremely clean
water, distilledwater, or deionized water, the nonferrous
construction option isstrongly recommended. With this option, all
components in contactwith the process fluid are constructed of
nonferrous materials. Thesematerials include stainless steel,
bronze, brass, copper, plastic andrubber.
!!!!! Upgraded Pumps
The standard pumps that have been selected for each size chiller
willmeet the requirements of most applications; however, in certain
in-stances, larger pumps may be required to provide the desired
flow andpressure for a specific application. The horsepower of the
pump willbe indicated on the nameplate on the chiller.
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Page 40
PREVENTIVE MAINTENANCE
Once your portable chiller has been placed into service, the
followingmaintenance procedures should be adhered to as closely as
possible.The importance of a properly established preventive
maintenanceprogram cannot be overemphasized. Taking the time to
follow thesesimple procedures will result in substantially reduced
downtime,reduced repair costs, and an extended useful lifetime for
the chiller.Any monetary costs of implementing these procedures
will almostalways more than pay for itself.
To make this as simple as possible, a checklist should be
preparedwhich lists the recommended service operations and the
times atwhich they are to be performed. On the following page, we
haveincluded a checklist that can be used for this purpose. Notice
thatthere are locations for voltage readings, amperages, etc. so
that theycan be monitored over time. With this information,
maintenancepersonnel may be able to correct a potential problem
before it causesany downtime. For best results, these readings
should be taken with afull heat load from process, preferably with
similar operating condi-tions each time.
The following is a list of suggested periodic maintenance.
!!!!! Once a Week
1. (Air Cooled Units Only) Check the surface of the air
cooledcondenser coil for dirt and debris. Clean out with compressed
airif necessary.
2. Check to make sure that the To Process temperature is
maintainedreasonably close to the Set Point temperature. If the
temperaturestays more than 5F (3C) away from the set point, there
may be aproblem with the chiller. If this is the case, refer to the
Trouble-shooting Chart or contact the Service Department.
3. Check the pump discharge pressure on the gauge on the
backpanel of the chiller. Investigate further if the pressure
starts tostray away from the normal operating pressure.
4. Check the coolant level in the reservoir. Replenish if
necessarymaking sure to take proper precautions to maintain the
appropri-ate glycol concentration.
5. Check coolant circulation pump for leaks in the seal area.
Replacepump seal if necessary.
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Page 41
6. Check refrigerant sight glass for air bubbles or moisture
indica-tion. If the sight glass indicates that there is a
refrigerationproblem, have the unit serviced as soon as
possible.
Repeat items 1 through 6 as listed above and continue with
thefollowing.
!!!!! Once a Month
7. With the main disconnect shut off, check the condition of
electricalconnections at all contactors, starters and controls.
Check for looseor frayed wires.
8. Check the incoming voltage to make sure it is within 10% of
thedesign voltage for the chiller.
9. Check the amp draws to each leg of the compressor and pump
toconfirm that they are drawing the proper current.
Repeat items 1 through 9 listed above and continue with
thefollowing.
!!!!! Every Three Months
10. 5 HP through 30 HP units are equipped with a Y-strainer
betweenthe pump discharge and the evaporator inlet. The strainer
basketshould be removed and cleaned if necessary. This may be
requiredmore often if contaminants can easily get into the process
water.
11. Have a qualified refrigeration technician inspect the
operation ofthe entire unit to ensure that everything is operating
properly.Have condenser cleaned out if necessary.
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Page 42
Thermal Care Preventive Maintenance Checklist
Week NumberMaintenance Activity 1 2 3 4 5 6 7 8 9 10 11 12
13DateTemperature ControlPump Discharge PressureCoolant LevelGlycol
ConcentrationPump Seal Refrigerant Sight GlassElectrical
ConnectionsIncoming VoltageCompressor L1 AmpsCompressor L2
AmpsCompressor L3 AmpsPump L1 AmpsPump L2 AmpsPump L3 AmpsClean
Y-strainerRefrigerant Circuit CheckRefrigerant Suction
PressureRefrigerant Discharge PressureRefrigerant SuperheatClean
Out Condenser
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Page 43
TROUBLESHOOTING
Problem
Compressor will notstart
Remedy
Check supply voltageCheck amperages of each lineCheck compressor
contactor andwiring
Replace if faulty
Replace if faulty
Contact refrigeration servicetechnician
Possible Cause
Compressor internal thermaloverload
Compressor contactor
Microprocessor control board
Compressor failure
Remedy
Check supply voltageCheck amperages of each lineCheck overload
settingReplace overload if faulty
Replace if faulty
Replace if faulty
Replace if faulty
Problem
Pump will not start
Possible Cause
Pump overload
Pump contactor
Microprocessor control board
Pump failure
Problem
Low refrigerantpressure
Possible Cause
Low refrigerant charge
Refrigerant leak
Compressor suction servicevalve partially closed
Low refrigerant pressurecontrol
Microprocessor control board
Remedy
Contact refrigeration servicetechnician
Contact refrigeration servicetechnician
Open valve all the way
Check for proper settingReplace if faulty
Replace if faulty
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Page 44
Possible Cause
Dirty condenser coil (air cooledunits only)
Air flow obstruction (air cooledunits only)
High ambient air temperature(air cooled units only)
Condenser fan (air cooled unitsonly)
Condenser fan cycling controls(air cooled units only)
Plugged condenser (watercooled units only)
Insufficient condenser waterflow
High condenser watertemperature
Condenser water regulatingvalve
Compressor discharge servicevalve partially closed
Refrigerant circuit overcharged
High refrigerant pressurecontrol
Microprocessor control board
Remedy
Clean out with compressed air
Make sure chiller is installed inaccordance with
recommendationsin this manual
Maximum temperature is 110F(43C)
Replace if faulty
Confirm proper operationReplace if faulty
Clean out
Make sure chiller is installed inaccordance with
recommendationsin this manual
Maximum temperature is 100F(38C)
Replace if faulty
Open valve all the way
Contact refrigeration servicetechnician
Replace if faulty
Replace if faulty
Problem
High refrigerantpressure
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Page 45
Problem
Freezestat
Possible Cause
Low flow through evaporator
Freezestat control
Microprocessor control board
Thermocouple
Remedy
Adjust flow to proper level
Check for proper settingReplace if faulty
Replace if faulty
Replace if faulty
Problem
Low pump dis-charge pressure
Possible Cause
Pump running backwards
No restriction in process orpiping
Pressure gauge
Pump failure
Remedy
Switch two legs of the incom-ing power
Slightly close off To Processthrottling valve
Replace if faulty
Replace if faulty
Problem
High pumpdischarge pressure
Possible Cause
Closed valves in process piping
Closed To Process throttlingvalve
Obstruction in piping or pro-cess
Clogged Y-strainer
Pressure gauge
Remedy
Open valves
Open valve
Clear obstruction
Clean strainer
Replace if faulty
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Page 46
Problem
Insufficient cooling(temperaturecontinues to riseabove set
point)
Possible Cause
Process load too high
Coolant flow through evapora-tor too high or too low
Insufficient condenser cooling
Hot gas bypass valve stuckopen
Refrigeration circuit problem
Microprocessor control board
Thermocouple
Remedy
Check to make sure chiller isproperly sized for process load
Adjust flow to proper level
See High Refrigerant Pressure
Contact refrigeration servicetechnician
Contact refrigeration servicetechnician
Replace if faulty
Replace if faulty
Problem
Erratic tempera-ture control
Possible Cause
Low coolant flow throughevaporator
Intermittent overloading ofchiller capacity
Hot gas bypass valve
Microprocessor control board
Thermocouple
Remedy
Adjust flow to proper level
Check to make sure chiller isproperly sized for process load
Contact refrigeration servicetechnician
Replace if faulty
Replace if faulty
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Page 47
PUMP CURVES
Portable ChillerPump Curves
SPA-1791
Flow (GPM)
Pum
p Pr
essu
re (P
SI)
3500 RPM pumps. Curves represent pump discharge. Correct for
unit discharge.
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Page 48
AQ0A0HElectrical Wiring Diagram
DIAGRAMS
EWC-0767
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Page 49
AQ0A01Electrical Wiring Diagram
EWC-0771
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Page 50
AQ0A02 - AQ0A10Electrical Wiring Diagram
EWC-0731
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Page 51
DIAGRAMS
EWC-0751
AQ0W02 - AQ0W05Electrical Wiring Diagram
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Page 52
AQ0W08 - AQ0W10Electrical Wiring Diagram
EWC-0755
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Page 53
AQ1W05 - AQ1W15Electrical Wiring Diagram
EWC-0763
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Page 54EWC-0884
AQ1W20-AQ1W30Electrical Wiring Diagram
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Page 55
AQ1W35 - AQ1W40Electrical Wiring Diagram
EWC-0894
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Page 56
AIR COOLED DIMENSIONS
Chilled WaterReturn
SPB-2439
Air Cooled (5 1/2 - 10 HP)
Air Cooled (1/2 - 3 HP)
SPA-2537
Chilled WaterSupply
Chilled Water SupplyChilled Water Return
ElectricalKnock-Out
Pressure Gauge
Sight Glass
PressureGauge
ElectricalKnock-Out
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Page 57
WATER COOLED DIMENSIONS
Sight GlassElectricalKnock-Out
Chilled Water ReturnChilled Water Supply
Condenser Water OutCondenser Water In
Water Cooled (2 - 5 HP)
Water Cooled (8 - 30 HP)
Condenser Water In
Condenser Water Out
Chilled Water ReturnChilled Water Supply
SPB-2550
Pressure Gauge
SPA-2549
PressureGauge
Chilled Water Supply
Chilled Water Return
CondenserWater In
CondenserWater Out
SPD-1780
Water Cooled (35 - 40 HP)
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Page 58
WARRANTYThermal Care warrants its equipment to be free from
defects in material and workmanshipwhen used under recommended
operating conditions.
Thermal Care's obligation is limited to repair (i.e. rewind a
motor) or replacement (notadjustment or maintenance), F.O.B. the
factory of any parts supplied by Thermal Care for aperiod of
eighteen months (twelve months for 1/2 and 1 HP compressor units)
from date ofshipment to the original purchaser. The microprocessor
is provided with a five year partswarranty. All units with 2 HP or
larger compressors include a labor warranty in the conti-nental
United States, Canada, Puerto Rico and select portions of Mexico.
Refrigerant and anylabor associated with its evacuation or
replacement are not covered by this warranty.
This warranty does not cover the cost of labor during overtime
hours (after normal workinghours or during weekends and holidays).
Any cost differential for overtime labor will be theresponsibility
of the customer. Thermal Care is not responsible for any sales,
use, excise orother applicable taxes associated with the
replacement of parts under this warranty. Thiswarranty will be
voided when, in Thermal Cares opinion, the equipment and/or system
hasbeen subject to misuse, negligence or operation in excess of
recommended limits, includingfreezing, or has been altered, and/or
repaired without express factory authorization. Ifequipment is
installed in hostile environments, unless such conditions were
specified at thetime of purchase; or the serial number has been
removed or defaced this warranty shall notapply. This warranty is
not transferrable.
Under no circumstances shall Thermal Care be liable for loss of
prospective or speculativeprofits, or special, indirect, incidental
or consequential damages.
All warranty service must be authorized by Thermal Care prior to
work being performed andhave a Thermal Care purchase order issued.
All defective parts become the property ofThermal Care and must be
returned as advised by Thermal Care.
Thermal Care neither assumes, nor authorizes any person to
assume for it, any liability notexpressed in this warranty. There
is an implied warranty of merchantability and of fitness
forparticular purpose; all other implied warranties, and any
liability not based upon contract arehereby disclaimed and excluded
by this warranty. This warranty is part of the standardconditions
and terms of sale of Thermal Care.
7720 N. Lehigh Ave.Niles, IL 60714-3491Phone: 847-966-2260, ext.
2900Fax: 847-966-9358
Customer ServicePhone 847/966-2636Fax 847/966-2906
e-mail: [email protected]
Form 1-407
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Form 2-325.15/00