Product Data 50JZ Single-Package Heat Pump Units with Puron® (R-410A) Refrigerant 2 to 5 Nominal Tons Copyright 2001 Carrier Corporation Form 50JZ-3PD Single-Package Products with Energy-Saving Features and Puron® refrigerant. • 12 SEER • HSPF up to 7.2 • Low Sound Levels • Variable Speed Blower Option Features/Benefits One-piece Heat Pump unit with optional electric heater, low installation cost, dependable performance and easy maintenance. Efficient operation High-efficiency design with SEERs (Seasonal Energy Efficiency Ratio) of 12.0. Puron® Environmentally Sound Refrigerant is Carrier’s unique refrigerant designed to help protect the environment. Puron is an HFC refrigerant which does not contain chlorine that can harm the ozone layer. The most important advantage of Puron refrigerant is that it has not been banned in future air conditioning systems as the traditional refrigerant R-22 has been. Puron refrigerant is in service in over 100,000 systems proving highly reliable, environmentally sound performance. ComfortHeat™ Technology featuring Variable Speed Blower motors provides better comfort and energy efficiency. You can expect up to 30 times better dehumidification; a SEER boost of up to 12.7; economical constant fan for less than $30 a year, which provides improved indoor air quality and more even temperatures from room to room; and reduced indoor noise due to lower air velocity. In addition, you’ll realize improved installation flexibility with 3 different airflow choices for best overall comfort. Easy Installation Factory-assembled package is a UNIT 50JZ
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Product 50JZ Data Single-Package Heat Pump Units · 2 compact, fully self-contained, heat pump unit that is pre-wired, pre-piped, and pre-charged for minimum installation expense.
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ProductData
50JZSingle-Package
Heat PumpUnits
with Puron® (R-410A) Refrigerant
2 to 5 Nominal Tons
Copyright 2001 Carrier Corporation Form 50JZ-3PD
Single-Package Products with Energy-Saving Features and Puron® refrigerant.• 12 SEER• HSPF up to 7.2• Low Sound Levels• Variable Speed Blower Option
Features/Benefits
One-piece Heat Pump unit with optional electric heater, low installation cost, dependable performance and easy maintenance.
Efficient operation
High-efficiency design
with SEERs (Seasonal Energy Efficiency Ratio) of 12.0.
Puron® Environmentally Sound Refrigerant
is Carrier’s unique refrigerant designed to help protect the environment. Puron is an HFC refrigerant which does not contain chlorine that can harm the ozone layer. The most important advantage of Puron refrigerant is that it has not been banned in future air conditioning systems as the traditional refrigerant R-22 has been. Puron refrigerant is in service in over 100,000 systems proving highly reliable, environmentally sound performance.
provides better comfort and energy efficiency. You can expect up to 30 times better dehumidification; a SEER boost of up to 12.7; economical constant fan for less than $30 a year, which provides improved indoor air quality and more even temperatures from room to room; and reduced indoor noise due to lower air velocity. In addition, you’ll realize improved installation flexibility with 3 different airflow choices for best overall comfort.
Easy Installation
Factory-assembled package
is a
UNIT 50JZ
2
compact, fully self-contained, heat pump unit that is pre-wired, pre-piped, and pre-charged for minimum installation expense. 50JZ units are available in a variety of standard capacity ranges with voltage options to meet residential and light commercial requirements. Units install easily on a rooftop or at ground-level.
Durable, dependable components
Compressors
are designed for high efficiency. Each compressor is hermetically sealed against contamination to help promote longer life and dependable operation. Vibration isolation provides quiet operation. Compressors have internal high-pressure and overcurrent protection.
Convertible duct configuration
Unit is designed for easy use in either downflow or horizontal applications. Each unit is easily converted from horizontal to downflow and include horizontal duct covers.
Direct-drive multi-speed, PSC (permanent split capacitor) blower motor
is standard on all 50JZ models.
Direct-drive, PSC condenser-fan motors
are designed to help reduce energy consumption and provide for cooling operation down to 40°F outdoor temperature. Motormaster® II low ambient kit is available as a field-installed accessory.
Corporate thermostats
designed to work as a system with Carrier’s small packaged product.
Refrigerant system
is designed to provide dependability. Liquid refrigerant filter driers are used to promote clean, unrestricted operation. Each unit leaves the factory with a full Puron® refrigerant charge. Refrigerant service connections make checking operating pressures easier.
Indoor and Outdoor coils
are computer-designed for optimum heat transfer and cooling efficiency. The indoor coil is fabricated from copper tube and aluminum fins and is located inside the unit for protection against damage. The outdoor coil is internally mounted on the top tier of the unit. Copper fin coils and pre-coated fin coils are available from the factory by special order. These coils are recommended in applications where aluminum fins are likely to be damaged due to corrosion. They are ideal for seacoast applications.
High and Low Pressure Switches
give added safety and reliability to the compressor.
Low sound ratings
ensure a quiet indoor and outdoor environment with sound ratings as low as 72 dB.(See page 3.)
Easy to service cabinets
provide easy single-panel accessibility to serviceable components during maintenance and installation. The basepan with integrated drain pan provides easy ground level installation with or without a mounting pad. Convenient handholds are provided to manipulate the unit on the jobsite. A nesting feature ensures a positive basepan to roof curb seal when
the unit is roof mounted. A convenient 3/4-in. wide perimeter flange makes frame mounting on a rooftop easy.
Louvered Grille
provides hail and vandalism protection for the coil.
Downflow operation
is easily provided in the field to allow vertical ductwork connections. The basepan utilizes knockout style seals on the bottom openings to ensure a positive seal in the horizontal airflow mode.
Cabinets
are constructed of heavy-duty, phosphated, zinc-coated prepainted steel capable of withstanding 500 hrs of salt spray. Interior surfaces of the evaporator and electric heater compartments are insulated with cleanable semi-rigid insulation board, which keeps the conditioned air from being affected by the outdoor ambient temperature and provides improved indoor air quality. (Conforms to American Society of Heating, Refrigeration and Air Conditioning Engineers No. 62P.) The sloped drain pan minimizes standing water in the drain, which is provided with an external drain.
Standard metal duct covers
with insulation come with the unit and cover the horizontal duct openings. These can be left in place if the units are converted to downflow.
Short-Cycling protection
for the compressor is incorporated into our defrost control board ensuring a five minute delay (+/-2 minutes) before restarting compressor after shutdown for any reason.
† Rated in accordance with U.S. Government DOE (Department of Energy) test procedures and/or ARI Standard 210/240-94.
‡ Tested in accordance with ARI Standard 270-95 (not listed in ARI).NOTES:1. Ratings are net values, reflecting the effects of circulating fan heat.
Ratings are based on:
Cooling Standard:
80°F db, 67°F wb indoor entering-air tempera-ture and 95°F db outdoor entering-air temperature.
2. Before purchasing this appliance, read important energy cost andefficiency information available from your retailer.
Model number nomenclature
50JZ 024 3 VS
Model Number
50JZ
– Single Packaged Heat Pump
Nominal Cooling Capacity024
– 2 ton
030
– 2.5 ton
036
– 3 ton
042
– 3.5 ton
048
– 4 ton
060
– 5 ton
V-Ph-Hz3
– *280/230-1-60
5
– 208/230-3-60
6
– 460-3-60
AL
— Aluminum
CU
— Copper
Options
BT
– AL evap, vinyl condens
CC
– AL evap, CU condens
CU
– CU evap & condens
VS
– Variable speed (VS) Unit
VT
– VS, AL evap, vinyl condens
VC
– VS, AL evap, CU condens
VU
– VS, CU evap & condens Only used if ordering an option
*Variable speed models are only available in 208/230-1-60 (3)
4
Physical data
* Required filter sizes shown are based on the larger of the ARI (Air Conditioning & Refrigeration Institute) rated cooling airflow or the heating airflow velocity of 300 ft/minute for throwaway type or 450 ft/minute for high-capacity type. Air filter pressure drop for non-standard filters must not exceed 0.08 in. wg.
UNIT SIZE 50JZ 024 030 036 042 048 060
NOMINAL CAPACITY (ton)
2 2-1/2 3 3-1/2 4 5
OPERATING WEIGHT (lb)
299 320 328 350 355 428
COMPRESSOR
Scroll
REFRIGERANT (R-410A)Quantity (lb)
7.0 8.9 9.3 9.5 10.6 12.4
REFRIGERANT METERING DEVICEOrifice ID (in.)Orifice OD (in.)
20 x 20 x 1 20 x 20 x 1 20 x 24 x 1 24 x 30 x 1 24 x 30 x 1 24 x 30 x 1
32 5
A2
MA
NU
FAC
TUR
ER
CERTIFIED TO ARI AS COMPLY
ING
WITH
ARI STANDARD 210
UN
ITAR
Y
AIR CONDITIO
NIN
G
EQUIPMENT
OUTDOOR SOUND: OCTAVE BAND DATA—DECIBELS (L w(A))
MODEL NO. 50JZ
Frequency (Hz) 024 030 036 042 048 060
63
44.4 43.9 53.6 47.7 57.1 54.6
125
57.5 55.9 63.6 60.4 63.9 64.1
250
61.1 60.9 66.6 64.0 70.4 68.6
500
68.0 66.9 71.1 67.5 72.7 71.2
1000
68.4 67.2 73.2 68.9 73.7 73.9
2000
64.5 63.8 69.6 64.9 71.1 69.8
4000
59.0 62.4 65.9 62.0 66.7 68.1
8000
51.7 52.1 58.4 55.0 59.7 61.8
5
Factory-installed optionsCoil options
include copper/copper and vinyl-coated construction for refrigerant coils. Units are shipped standard with copper tube/aluminum fin construction. See model number nomenclature for coil options.
Electronic Variable-Speed Motors
— ICM Motors (Integrated Control Motor) provide variable-speed operation to optimize comfort levels year round. They are also more economical to operate than standard motors.
Field-installed accessories
Economizer with solid-state controls and barometric relief dampers
includes filter racks and provide outdoor air during cooling and reduce compressor operation.
Manual outside air damper
includes hood and filter rack with adjustable damper blade for up to 25% outdoor air.
Electric heaters
provide additional heat in the unit when required. Each package has a heater module that slides into the controls compartment. Heater sizes range from 5.0 to 20.0 kw. The electric heater design allows the use of a single-point power supply for the entire unit, resulting in lower installed costs.
Flat roof curbs
in both 8 in. and 14 in. sizes are available for roof mounted applications.
Square-to-round duct transition kit
enables 024-048 size units to be fitted to 14 in. round ductwork.
Thermostats
provide control for the system heating and cooling functions. Thermostat models are available in both programmable and non-programmable versions.
Lifting kit
includes 4 metal brackets that fit into the hand-holds, a support strap and two safety straps, is available to assist in lifting this product onto a roof application.
Crankcase heater
provides anti-floodback protection for low-load cooling applications (Standard on 50JZ 042-060).
Low-ambient kit (Motormaster II control)
allows the use of mechanical cooling down to outdoor temperatures as low as 0°F.
Filter rack
features easy installation, serviceability, and high-filtering performance for vertical applications.
Compressor Hard start kit
assists compressor start-up by providing additional starting torque on single phase units and prolongs compressor motor life.
Economizer with Solid-State Controls and Barometric
Relief Dampers
Manual Air Damper (25% open)
Electric Heaters
Filter Rack
Flat Roof Curbs (8-in. and 14-in.)
Square-to-Round Duct Transition Kit
Thermostats
Crankcase Heater
Low Ambient Kit (Motormaster® II Control)
Lifting Kit
Compressor Hard Start Kit
Options and accessories
ELECTRIC HEATERS
LEGENDODS — Order Distribution SystemNOTE: Electric heaters are rated at 240v and 480v. Refer to Multiplication Factors table for other voltages.
MINIMUM AIRFLOW FOR RELIABLE ELECTRIC HEATER OPERATION
ODS CATALOGORDERING NO.
NOMINAL CAPACITY (kW)
USED WITH SIZES024 030 036 042 048 060
ELECTRIC HEATERS (208/230 — SINGLE PHASE — 60 Hz)CPHEATER052A00
5.0 X X X X
CPHEATER064A00
5.0 X X
CPHEATER070A00
7.5 X X X X X X
CPHEATER050A00
10.0 X X X X X X
CPHEATER066A00
15.0 X X X X X
CPHEATER054A00
20.0 X X X
ELECTRIC HEATERS (208/230 — 3 PHASE — 60 Hz)CPHEATER055A00
5.0 X X X X X
CPHEATER056A00
10.0 X X X X
CPHEATER068A00
10.0 X
CPHEATER058A00
15.0 X X X X X
CPHEATER067A00
20.0 X X X
ELECTRIC HEATERS (460 V — 3 PHASE — 60 Hz)CPHEATER060A00
Notes:1. Roof curb must be set up for unit being installed.2. Seal strip must be applied, as required, to unit being installed.3. Dimensions in [ ] are in millimeters.4. Roof curb is made of 16-gage steel.5. Table lists only the dimensions, per part number, that have changed.6. Attach ductwork to curb (flanges of duct rest on curb).7. Insulated panels: 1-in. thick fiberglass 1 lb. density.8. Dimensions are in inches.9. When unit mounting screw is used (Note A), a retainer bracket must be used as
well. This bracket must also be used when required by code for hurricane or seismic conditions. This bracket is available through Micrometl.
II Select unit based on required cooling capacity.Enter Net Cooling Capacities table at condenser enteringtemperature of 95°F. The 50JZ036 unit at 1200 cfm and67°F ewb (entering wet bulb) will provide a total capacityof 36,600 Btuh and a SHC of 28,200 Btuh. Calculate SHCcorrection, if required, using Note 4 under CoolingCapacities tables.
III Select electric heat.Enter the 50JZ036 unit Heating Extended Performancetable at 1200 cfm. At 70°F return indoor air and 20°F airentering outdoor coil, the integrated heating capacity is17,400 Btuh. (Select integrated heating capacity valuesince deductions for outdoor-coil frost and defrosting havealready been made. No correction is required.) The required heating capacity is 25,000 Btuh. Therefore,7,600 Btuh (25,000 – 17,400) additional electric heat isrequiredDetermine additional electric heat capacity in kw. 7,600 Btuh3414 Btuh/kW
Enter the Electric Heater table on page 5 for 208/230 v,single-phase, unit. The 5-kw heater at 240v most closelysatisfies the heating required. To calculate kw at 230v,multiply the heater kw by multiplication factor 0.92 foundin the Multiplication Factors table on page 17.5 kw x 0.92 = 4.6 kw4.6 kw x 3414 Btuh/kw = 15,704 BtuhTotal unit heating capacity is 33,104 Btuh (17,400 +15,704).
IV Determine fan speed and power requirements at design conditions.Before entering the air delivery tables, calculate the totalstatic pressure required. From the given, Filter PressureDrop Table, Electrical Heat Pressure Drop table, and theWet Coil Pressure Drop table, find:External static pressure 0.200 in. wgFilter 0.130 in. wgElectric Heaters 0.000 in. wg
Total static pressure 0.330 in. wg
Enter the table for Wet Coil Air Delivery — (230 and460v.) At 0.33 in. wg external static pressure and highspeed, the motor delivers 1238 cfm, and 605 watts.
V Select unit that corresponds to power source available.The Electrical Data table shows that the unit is designed tooperate at 208/230-1-60.
LEGENDEwb – Entering Wet-BulbkW – Total Unit Power InputSHC – Sensible Heat Capacity (1000 Btuh)TC – Total Capacity (1000 Btuh) (net)
NOTES:1. Ratings are net; they account for the effects of the evaporator-fan motor power and heat.2. Direct interpolation is permissible. Do not extrapolate.3. The following formulas may be used:
sensible capacity (Btuh)t = t �ldb edb 1.10 x cfm
t = Wet-bulb temperature corresponding to enthalpy of air leavinglwbevaporator coil (h )lwb
total capacity (Btuh)h = h �lwb ewb 4.5 x cfm
Where: h = Enthalpy of air entering evaporator coilewb
Performance data (cont)ECONOMIZER 1-in. FILTER PRESSURE DROP (in. wg)
MULTIPLICATION FACTORS
Example: 15.0 kw (at 240v) heater on 208v= 15.0 (.75 mult factor)= 11.25 capacity at 208v
UNIT50JZ PRESSURE DROP
024-036 0.20
042-060 0.25
HEATER kwRATING
VOLTAGEDISTRIBUTION V/3/60
MULTIPLICATIONFACTOR
240
200208230240
.69
.75
.921.00
480440460480
.84
.921.00
LEGENDBF — Bypass FactorEwb — Entering Wet-BulbkW — Total Unit Power InputSHC — Sensible Heat Capacity (1000 Btuh)TC — Total Capacity (1000 Btuh) (net)PSC — Permanent Split CapacitorEdb — Entering Dry-Bulbrh — Relative Humidity
— Indicates Integrated Ratings
4. The SHC is based on 80°F edb temperature of air entering evaporatorcoil. Below 80°F edb, subtract (corr factor x cfm) from SHC.Above 80°F edb, add (corr factor x cfm) to SHC.Correction Factor = 1.10 x (1 + BF) x (edb + 80).
5. Integrated capacity is maximum (instantaneous) capacity less the effectof frost on the outdoor coil and the heat required to defrost it.
NOTES:1. Ratings are net; they account for the effectsof the evaporator-fan motor power and heat.2. Direct interpolation is permissible. Do not extrapolate.3. The following formulas may be used:
STANDARD 50JZ UNIT 024-060—WET COIL AIRFLOW DELIVERY
*Air delivery values are based on operating voltage of 230 v or 460 v, wet coil, without filter or electric heater. Deduct filter and electric heater pressuredrops to obtain static pressure available for ducting.NOTES: 1. Do not operate the unit at a cooling ariflow that is less than 350 cfm for each 12,000 Btuh of rated cooling capacity. Evaporator coil frosting mayoccur at airflows below this point.2. Dashes indicate portions of table that are beyond the blower motor capacity or are not recommended.3. Deduct 10% for 208v.
Based on Indoor Entering Air of 70 F and Rated CFM
Condensate trap — A 2-in. condensate trap must be fieldsupplied.
Ductwork — Secure downflow discharge ductwork to roofcurb. For horizontal discharge applications, attach ductworkto unit with flanges.To convert a unit to downflow discharge — Units areequipped with factory-installed inserts in the downflowopenings. Remove the inserts similar to removing an
electrical knock-out. Leave on duct covers to seal thehorizontal discharge openings in the unit. Units installed inhorizontal discharge orientation do not require duct covers.
Maximum cooling airflow — To minimize the possibilityof condensate blow-off from the evaporator, airflow throughthe units should not exceed 450 cfm/ton.
Minimum cooling airflow — The minimum cooling airflowis 350 cfm/ton.
Minimum cooling ambient operating temperature — Allstandard units have a minimum ambient operatingtemperature of 40°F. Units with the ICM Indoor Motor FIOPhave a minimum cooling outdoor operating temperature of55°F. With accessory low ambient temperature kit, units canoperate at temperatures down to 0°F.
Maximum operating outdoor air temperature — Maximumoutdoor operating air temperature for cooling is 125°F.
Application data
1” MIN.
2” MIN.
TRAPOUTLET
22
Electrical dataUNITSIZE50JZ
V-PH-Hz
VOLTAGERANGE COMPRESSOR OUTDOOR
FAN MOTORINDOOR
FAN MOTOR ELECTRIC HEATSINGLE POINT
POWER SUPPLY
Min Max RLA LRA FLA FLA Nominal kw* FLA UNIT MCAMAX FUSE
NOTES:1. In compliance with NEC (National Electrical Code) requirements
for multimotor and combination load equipment (refer to NECArticles 430 and 440), the overcurrent protective device for theunit shall be Power Supply fuse . The CGA (Canadian GasAssociation) units may be fuse or circuit breaker.
2. Minimum wire size is based on 60 C copper wire. If other than60 C wire is used, or if length exceeds wire length in table,determine size from NEC.
3. Unbalanced 3-Phase Supply VoltageNever operate a motor where a phase imbalance in supply volt-age is greater than 2%. Use the following formula to determinethe percentage of voltage imbalance.
% Voltage imbalance
max voltage deviation from average voltage= 100 xaverage voltage
EXAMPLE: Supply voltage is 460-3-60.AB = 452 vBC = 464 vAC = 455 v
452 + 464 + 455Average Voltage =3
1371=3
= 457
Determine maximum deviation from average voltage.(AB) 457(BC) 464(AC) 457
Maximum deviation is 7 v.
Determine percent of voltage imbalance.7% Voltage Imbalance = 100 x
457
= 1.53%
This amount of phase imbalance is satisfactory as it is below themaximum allowable 2%.
IMPORTANT: If the supply voltage phase imbalance ismore than 2%, contact your local electric utility companyimmediately.
®
*Heater capacity (KW) based on heater voltage of 208v, 240v, & 480v.If power distribution voltage to unit varies from rated heater voltage,heater KW will vary accordingly.
50JZ WITH ICM FIOP ELECTRICAL DATA
UNITSIZE50JZ
V-PH-Hz
VOLTAGERANGE COMPRESSOR OUTDOOR
FAN MOTORINDOOR
FAN MOTOR ELECTRIC HEATSINGLE POINT
POWER SUPPLY
Min Max RLA LRA FLA FLA Nominal kw* FLA UNIT MCAMAX FUSE
or CKT. BKR. MOCP
024 208/230-1-60 187 253 13.5 61.0 0.9 4.3
—/—3.8/5.05.4/7.27.5/10.0
—/—18.1/20.825.9/30.036.1/41.7
22.1/22.144.6/48.154.5/59.667.2/74.2
30/3050/5060/–—
——
–/7070/80
030 208/230-1-60 187 253 15.9 73.0 0.9 4.3
—/—3.8/5.05.4/7.27.5/10.011.3/15.0
—/—18.1/20.825.9/30.036.1/41.754.2/62.5
25.1/25.147.6/51.157.4/62.670.2/77.292.8/103.2
30/3050/50
———
——
70/7080/80
100/110
036 208/230-1-60 187 253 16.9 83.0 1.6 6.8
—/—3.8/5.05.4/7.27.5/10.011.3/15.0
—/—18.1/20.825.9/30.036.1/41.754.2/62.5
29.5/29.552.1/55.661.9/67.074.7/81.697.2/107.7
40/4060/60
———
——
70/8080/90
100/110
042 208/230-1-60 187 253 22.4 105.0 0.9 6.8
—/—3.8/5.05.4/7.27.5/10.011.3/15.015.0/20.0
—/—18.1/20.825.9/30.036.1/41.754.2/62.572.2/83.3
35.7/35.758.3/61.768.1/73.280.8/87.8
103.4/113.0126.0/139.9
50/50—————
—70/7080/8090/90
110/125150/150
048 208/230-1-60 187 253 21.3 109.0 1.6 6.8
—/—3.8/5.05.4/7.27.5/10.011.3/15.015.0/20.0
—/—18.1/20.825.9/30.036.1/41.754.2/62.572.2/83.3
35.0/35.057.6/61.167.4/72.580.2/87.1
102.7/113.2125.3/139.2
50/50—————
—70/7080/8090/90
110/125150/150
060 208/230-1-60 187 253 27.6 158.0 1.6 9.2
—/—3.8/5.05.4/7.27.5/10.011.3/15.015.0/20.0
—/—18.1/20.825.9/30.036.1/41.754.2/62.572.2/83.3
45.1/45.167.7/71.177.7/82.890.3/97.2
112.8/123.2135.4/149.3
60/60—————
—80/8090/90
100/110125/125150/150
24
Typical wiring schematic — 208/230-1-60 shown
25
Typical wiring schematic — 208/230-3-60 shown
26
Typical wiring schematic — 460-3-60 shown
27
ICM FIOP wiring schematic — 208-230-1-60 shown
28
Sequence of operationWhen power is supplied to unit, the transformer (TRAN) isenergized.
On units with crankcase heater, heater is also energized.
Cooling — With the thermostat subbase in the coolingposition, the thermostat makes circuit R-O. This energizesthe reversing valve solenoid (RVS) and places the unit instandby condition for cooling.
As the space temperature rises, the thermostat makes,closing circuit R-Y. A circuit is made to contactor (C),starting the compressor (COMP) and outdoor-fan motor(OFM). Circuit R-G is made at the same time, energizing theindoor-fan relay (IFR) and starting the indoor-fan motor(IFM) after a 1-second delay†.
When the thermostat is satisfied, contacts open, deenergizingC. The COMP and OFM stop, and the IFM stops after a 60sec time delay†.
Heating — On a call for heat, thermostat makes circuits R-Y and R-G.
A circuit is made to C, starting COMP and OFM. Circuit R-G also is completed, energizing IFR and starting IFM after a1-sec delay†.
Should room temperature continue to fall, circuit R-W ismade through second-stage thermostat bulb. If optionalelectric heat package is used, a relay is energized, bringingon first bank of supplemental electric heat. When thermostatis satisfied, contacts open, deenergizing contactor and relay;
motors and heaters deenergize. The IFM is controlled by atime-delay relay that keeps the fan on for 60 sec†.
Defrost — Defrost board (DB) is a time and temperaturecontrol, which includes a field-selectable time period (Dipswitch 1 and 2 on the board) between checks for defrost (30,60, 90, or 120 minutes). Electronic timer and defrost cyclestart only when contactor is energized and defrost thermostat(DFT) is closed.
The defrost board is also equipped with a 3rd dip switch forselecting Quiet Shift operation. The Quiet Shift operationturns compressor off at defrost initiation and termination.Unit is factory shipped with quiet shift turned off.
Defrost mode is identical to cooling mode, except outdoorfan motor stops and a bank of optional electric heat turns onto warm air supplying the conditioned space.
NOTES:
1.† Standard PSC indoor motor.2. Compressor time delay occurs through the defrost controlboard.
3. Defrost control board has built in 5 minute compressordelay: once the compressor has started and then stopped, itcannot be restarted again until 5 minutes have elapsed.
4. ICM FIOP models only—The indoor blower operationwith a call for fan operation (G) in either cooling or heatpump heating (compressor) modes will perform by the on/off delay profile selected at start up on the easy select™board.
Controls
29
Packaged Heat Pump Units Constant Volume Application
HVAC Guide SpecificationsSize Range: 2 to 5 Tons, Nominal CoolingCarrier Model Number: 50JZPart 1—GeneralSYSTEM DESCRIPTION
Outdoor rooftop or ground mounted, heat pump unitutilizing a hermetic compressor for heating and cool-ing duty and optional electric heating. Unit shall dis-charge supply air vertically or horizontally as shownon contract drawings. Outdoor fan/coil section shallhave a draw-thru design with vertical discharge forminimum sound levels.
QUALITY ASSURANCEA. Unit shall be rated in accordance with ARI Standards
210/240-94 and 270-95.B. Unit shall be designed in accordance with UL Standard
1995.C. Unit shall be manufactured in a facility registered to
ISO 9001 manufacturing quality standard.D. Unit shall be UL listed and c-UL certified as a total
package for safety requirements.E. Roof curb shall be designed to conform to NRCA Stan-
dards.F. Insulation and adhesives shall meet NFPA 90A re-
quirements for flame spread and smoke generation.G. Cabinet insulation shall meet ASHRAE Standard 62P.
DELIVERY, STORAGE AND HANDLINGUnit shall be stored and handled per manufacturer’srecommendations.
Part 2 — ProductsEQUIPMENT
A. General:Factory-assembled, single-piece, heat pump unit. Con-tained within the enclosure shall be all factory wiring,piping, controls, refrigerant charge (R-410A), and spe-cial features required prior to field start-up.
B. Unit Cabinet:1. Unit cabinet shall be constructed of phosphated,
zinc-coated, pre-painted steel capable of withstand-ing 500 hrs of salt spray.
2. Normal service shall be through a single removablecabinet panel.
3. The unit shall be constructed on a rust proof basep-an that has an externally trapped, integrated slopeddrain pan.
4. Indoor fan compartment top surface shall be insulat-ed with a minimum 1/2-in. thick, flexible fiberglassinsulation, coated on the air side and retained by ad-hesive and mechanical means. The indoor wall sec-tions will be insulated with a minimum semi-rigidfoil-faced board capable of being wiped clean. Alu-minum foil-faced fiberglass insulation shall be usedin the entire indoor air cavity section.
5. Unit shall have a field-supplied condensate trap.C. Fans:
1. The indoor fan shall be 3-speed, direct-drive, or fac-tory installed optional variable speed motor andcontrol, as shown on equipment drawings.
2. Fan wheel shall be made from steel, and shall bedouble-inlet type with forward curved blades withcorrosion resistant finish. Fan wheel shall be dy-namically balanced.
3. Outdoor fan shall be direct drive propeller type withaluminum blades riveted to corrosion resistant steelspiders, be dynamically balanced, and discharge airvertically.
D. Compressor:1. Fully hermetic compressors with factory-installed
vibration isolation.2. Scroll compressors shall be standard on all units.3. Compressor Protection:
Defrost control shall protect compressor by prevent-ing “short cycling.”
E. Coils:Indoor and outdoor coils shall have aluminum platefins mechanically bonded to seamless copper tubeswith all joints brazed. (Copper/copper and vinyl-coat-ed construction available as option.) Tube sheet open-ings shall be belled to prevent tube wear.
F. Refrigerant Metering Device:Refrigerant metering device shall be of the single bodyfixed orifice feed type.
G. Filters:Filter section shall consist of field-installed, throw-away, 1-in. thick fiberglass filters of commerciallyavailable sizes.
H. Controls and Safeties:1. Unit controls shall be complete with a self-
contained low voltage control circuit.2. Units shall incorporate an internal compressor pro-
tector that provides reset capability.3. Unit shall provide High and Low/Loss-of-Charge
1. Unit shall be capable of starting and running at125°F ambient outdoor temperature, exceedingmaximum load criteria of ARI Standard 240-94.
2. Compressor with standard controls shall be capable ofoperation down to 40° F ambient outdoor temperaturein cooling (55°F with ICM FIOP) and -10°F in heating.
3. Unit shall be provided with 30 or 60-sec fan timedelay after the thermostat is satisfied with standardindoor blower motor.
4. On ICM FIOP-fan on/off delay profile is selected(for compressor modes) on the Easy Select™ board.
J. Electrical Requirements:All unit power wiring shall enter the unit cabinet at asingle location.
Guide specifications
30
K. Motors:1. Compressor motors shall be of the refrigerant-
cooled type with line-break thermal and currentoverload protection.
2. All fan motors shall have permanently lubricatedbearings, and inherent, automatic reset, thermaloverload protection.
3. Outdoor fan motor shall be totally enclosed.L. Grille
1. Louvered Grille:Louvered grille shall be standard on all units.
M. Special Features Available1. ICM FIOP:
Integral control motor for indoor blower shall be afactory installed option for optimizing comfort lev-els in all operating modes and increasing system ef-ficiency.
2. Coil Options:Shall include factory-installed optional copper/copper and vinyl-coated refrigerant coils.
3. Economizer:a. Economizer controls capable of providing free
cooling using outside air.b. Equipped with low leakage dampers not to ex-
ceed 3% leakage, at 1.0 in. wg pressure differen-tial.
c. Spring return motor shuts off outdoor damper onpower failure.
4. Flat Roof Curb:Curbs shall have seal strip and a wood nailer forflashing and shall be installed per manufacturer’sinstructions.
5. Manual Outdoor Air Damper:Package shall consist of damper, birdscreen, andrainhood which can be preset to admit outdoor airfor year-round ventilation.
6. Thermostat:To provide for two-stage heating and one stagecooling in addition manual or automatic changeoverand indoor fan control.
7. Low Ambient Package:Shall consist of a solid-state control and outdoorcoil temperature sensor for controlling outdoorfan motor operation, which shall allow unit to op-erate down to 0° F outdoor ambient temperaturein cooling.
8. Filter Rack Kit:Shall provide filter mounting for downflow applica-tions.
9. Square-To-Round Duct Transitions:Shall have the ability to convert the supply and re-turn openings from rectangular to round. (024-048only)
10. Crankcase Heater:Shall provide anti-floodback protection for low-load cooling applications. (Standard on 042-060sizes)
11. Electric heaters:a. Electric heater shall be available as a field-
installed option.b. Heater elements shall be open wire type, ade-
quately supported and insulated with ceramicbushings.
c. Electric heater packages must provide singlepoint power connection capability.
12. Compressor Hard start kit:Shall be available to give a boost to the compressormotor at each start-up.
Guide specifications (cont)
31
Carrier Corporation • Indianapolis, IN 46231 5-01
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4 Page 32 Catalog No. 525-00014 Printed in U.S.A. PC 101 Form 50JZ-3PD