Top Banner
Maytag Services Refrigerant Handling Standard Operating Procedures 1
63
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Page 1: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Maytag Services

Refrigerant Handling

Standard Operating Procedures

1

Page 2: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Federal EPA Refrigerant Recovery Guidelines

Page 3: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Licensing Requirements• Under section 608(c) of the 1990 Clean Air Act

Amendments, “… ( It is )unlawful for any person, in the course of maintaining, servicing, repairing or disposing of an appliance…. to knowingly vent or otherwise knowingly release or dispose of any Class I or Class II substance used as a refrigerant in such an appliance in a manner which permits such substance to enter the environment… “

• The Act further establishes that any technician that can be reasonably expected to enter a sealed system during the course of repair of a refrigeration appliance must be certified in refrigerant handling by a Federal EPA approved certification organization.

Page 4: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

EPA Penalties

• A willful release of refrigerants or failure to follow EPA recovery guidelines carries stiff penalties for the technician– $30,000 per occurrence– Up to 5 years jail time

• EPA offers a $10,000 reward to anyone reporting a violation

Page 5: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Certification ClassificationsThere are 4 certification classifications:• Type I- Allows technicians to perform service on

refrigeration equipment containing less than 5 lbs. of refrigerant.

• Type II- Allows technicians to work on refrigeration equipment containing more than 5 lbs. but less than 50 lbs. of refrigerant.

• Type III-Allows a technician to work on refrigeration equipment containing more than 50 lbs. of refrigerant

• Universal- Allows a technician to work on any refrigeration equipment, regardless of the amount of refrigerant.

Page 6: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Certification Guidelines

• Type I or Universal certification is required to work on residential refrigeration appliances. Type II and Type III certifications do not permit working on small appliances.

• Technicians are required to have valid certification cards on their person anytime that they are performing repairs on a refrigeration system.

Page 7: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

EPA Restrictions

• Purchase of refrigerant is restricted to certified technicians and Section 608(c) certified technicians can only purchase refrigerant in 30 lb. (minimum) containers.

• Recovery of refrigerants must be accomplished with an EPA approved recovery device. Two types of recovery devices are allowed.– Active- a recovery pump that is able to pull a system into a

minimum 4” vacuum.– Passive- a non powered device capable of capturing 80% of

the system charge (such Recovery bag)

Page 8: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

EPA Restrictions

• Use of refrigerant recovery bags, such as the Whirlpool Ozone Saver® Bag, is regulated by the EPA. Compliance requires:– The technician must recover a minimum of 80% of the

system charge. On a non working compressor, the base of the compressor must be heated and struck sharply with a hammer to free any refrigerant trapped in the compressor oil.

– Recovery bags are designed as temporary refrigerant storage devices and should be removed from vans each night.

– The bag can only be used 4 times before it is discarded.– The bag must be emptied within 48 hours– Torn or damaged bags must be discarded.

Page 9: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Recovered Refrigerant

• All Refrigerants must be recovered and reclaimed

• Mixed refrigerants cannot be reclaimed and must be destroyed– Some refrigerants (R-12, R-134a) have value on

the reclaim market. – Every pound we have to destroy not only costs us

$3-4 per pound to dispose of but we miss out on the reclaim income that would have been generated

Page 10: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Other EPA Recommendations

• All leaks should be located and repaired

• All hoses and manifold gauge sets must utilize low loss fittings

Page 11: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

US Department Of Transportation (DOT)

Guidelines

Page 12: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Material Safety Data Sheets (MSDS)

• Technicians are required to carry MSD Sheets for every type of chemical in their truck, including acetylene, oxygen, glues, cleaners and refrigerants.– Technicians should read and follow all

recommended safety guidelines when handling refrigerants and other chemicals.

Page 13: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Transportation of Refrigerants and other Compressed Gasses

• Refrigerant, acetylene, oxygen, nitrogen, etc. are all considered to be hazardous materials by US DOT. Shipping of these containers is highly regulated.– Before shipping any of these items by common carrier,

check with the carrier to determine packaging and Bill of Lading requirements.

– Air freighting of these items is strictly prohibited.

• All compressed gasses such as refrigerant, acetylene, oxygen, aerosol and paint cans, etc. must be in DOT approved containers and secured in the van with chains or other significant restraints to prevent containers from falling over, rolling around in the truck, etc.

Page 14: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Transportation of Refrigerants and other Compressed Gasses

• All cylinder valves should be completely closed and OXY/Acetylene regulators removed whenever a cylinder is being transported

• All cylinder must completely shut-off with no leaks

Page 15: Maytag Services Refrigerant Handling Standard Operating Procedures 1.
Page 16: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Transportation of Refrigerants and other Compressed Gasses

• The acetylene cylinder must not have been fully closed and a small leak occurred

• On the Monday morning when the van door was opened, a large explosion took place.

• Tech suffered damage to his ear drums and face.

Page 17: Maytag Services Refrigerant Handling Standard Operating Procedures 1.
Page 18: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Technician Name:__________________________ Service Vehicle #_____________________________________

Chemical Cylinder sizes # of Partially Filled

Cylinders

# of Full Cylinders

Acetylene, Dissolved

Chlorodifluoromethate (R-22)

Dicholorodifluoromethane (R-12)

Tetrafluoroethane (R-134a)

Oxygen, compressed

Nittrogen, compressed

Directions:

Example

Acetylene, Dissolved 2#, 5# 1 1

Under Cylinder sizes, list the size of the cylinders carried for the chemical in question (I.e. 2#, 30#, 50#)Under # of Partially filled cylinders, list how many of the cylinders are partially filledUnder full cylinders, list how many of the cylinder are full

Maytag Services Shipping Paper

Page 19: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Transportation of Refrigerants and other Compressed Gasses

• Transporting refrigerant in charging cylinders (such as Dial-a-Charge) is not permitted. Charging cylinders must be empty of refrigerant before transporting.

• Some states go as far as requiring that refrigerant be removed from self sealing hoses on compound gauges. To assure compliance, technicians should be sure to recover refrigerant from gauges before transporting.

Page 20: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Cylinder Safety

• New refrigerant is packaged in DOT 39 disposable cylinders. When empty, these cylinders must be disposed of properly. After evacuating the cylinder (to 0 PSIG), the valve must be removed. The tank can then be disposed of with other metal waste.

• Reuse of DOT 39 disposable cylinders (such as storing or carrying compressed air) is illegal and carries a penalty of $25,000 and up to 5 years in prison.

Page 21: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Cylinder Safety

• Recovered refrigerant can only be stored in DOT approved recovery cylinders (with the exception of temporary storage in a refrigerant recovery bag.)

• US DOT regulates that recovery cylinders must not be filled beyond 80% capacity. – Many of these tanks are equipped with a ball or

float switch that, when connected to a recovery pump, will shut the pump off when the 80% mark on the tank is reached.

Page 22: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Cylinder Safety

• If the cylinder is not equipped with a ball or float switch, the tank must be weighed prior to each recovery to insure that it can accept additional refrigerant. Cylinders are marked with their empty or tare weight (TW) and water content weight (WC). This represents the total weight of the cylinder and contents when the cylinder is filled to capacity.

• Sometimes the tank is marked with the tare weight and the “MAX. Gross WT ___ LB.” The max weight, again, represents the total weight of the cylinder when it’s filled to capacity.

Page 23: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Cylinder Safety

• To insure that the recovery tank is not filled beyond 80%, the technician must determine the max fill level for each tank. To do that, the technician must compute the WC weight (if not listed) and multiply by .8

• Example: MAX weight= 23.5 lbs, TW= 10.5 lbs. Max WC weight= 13 lbs. (23.5-10.5) Maximum refrigerant that can be put into tank=

10.4 lbs. (13 lbs. WC X 80%)

Page 24: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Cylinder Safety

• Overfilled cylinders present a serious safety hazard. Because liquids don’t compress, any rise in temperature can cause an over filled tank to explode. Technicians must avoid overfilling or exposing a tank to extreme temperatures. – In the summer, park in the shade whenever

possible– If the truck is equipped with vents, open them – Never use an open flame to heat a refrigerant

cylinder

Page 25: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Hydrostatic Cylinder Testing

• Recovery cylinders must be hydrostatically tested every five years. The last test date will be stamped or embossed on the shoulder of the cylinder. In most cases, the tank will clearly be marked with the first retest date. For example,

FIRST RETEST DATE06 07

RETEST EVERY FIVE YEARS

• This means that the tank must be submitted for testing prior to June of 2007 and every five years after that (on or before the month of June).

Page 26: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Hydrostatic Cylinder Testing

• Older tanks may have the date stamped on them in the pattern shown to the right. This stamp indicates the last retest date and the testing organization that completed the test.

• In this example, this cylinder was last tested on May of 2002 by tester A253. The next retest date, therefore, is May of 2007.

A2

05 0253

Page 27: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

• Technicians carrying tanks that are beyond the required test date must discontinue use of the cylinder immediately. – Filling of cylinders with expired test dates is

prohibited. – Any tank that has an expired test date

must be submitted to a reclaimer for refrigerant processing and cylinder testing.

Hydrostatic Cylinder Testing

Page 28: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Labeling of Refrigerant Cylinders

• All refrigerant cylinders, both new and recovered, must be properly labeled with their content. – If the recovery cylinder is in its original cardboard

carton, there are boxes printed on the carton that allow placing an X or a √ mark next to the type of refrigerant that is being carried.

– If out of the carton, most refrigeration supply houses supply stickers and/or tags that can be affixed to recovery cylinders to identify the contents.

Page 29: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Contaminated Refrigerants

• Normal contaminants, such as air, refrigerant oil and water that are mixed with refrigerants in a recovery cylinder are not an issue. Care should be taken, however, to insure that no other contaminants are added to the refrigerant.

• If a reclaimer suspects that a refrigerant tank is contaminated with unidentified chemicals, regulations require that the contents of the tank be analyzed and the refrigerant be disposed of. Reclaimers charge a fee for this service.

Page 30: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Mixed Refrigerants

• Mixing of refrigerants should be avoided. – Refrigerants are considered to be mixed when

more than 3% of a second refrigerant is added to the base refrigerant. For example, adding 1 lb of R-22 to a cylinder that contains 20 lbs of R-134a will render the entire tank as mixed.

– Mixed refrigerants cannot be easily or economically reclaimed and thus, must be destroyed. Instead of the usual $25 or $30 handling fee for accepting used refrigerant, the price to dispose of mixed refrigerants can exceed $100 per cylinder ($3-4 per pound).

Page 31: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Tracking of Refrigerant Usage and Recovery• The Federal EPA has the ability to subpoena

refrigerant usage records of an individual and/or a company to compare refrigerant purchases against recovery levels. – Since the minimum recovery level for any system

is 80%, a discrepancy between refrigerant purchased and refrigerant recovered could indicate that technicians are not recovering at mandated rates.

– Technicians must maintain logs to track refrigerant usage

Page 32: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Refrigerant Tracking Log

Technician____________________________________

Customer Last NameAddress

Serv. Ticket # Refrigerant Oz. Recvrd

Refrigerant Oz. Comments

Recovered Installed Used

    R-134a   R-134a    R-22 R-22

R-12 R-12

Other Drop-in

    R-134a   R-134a    R-22 R-22

R-12 R-12

Other Drop-in

    R-134a   R-134a    R-22 R-22

R-12 R-12

Other Drop-in

    R-134a   R-134a    R-22 R-22

R-12 R-12

Other Drop-in

    R-134a   R-134a    R-22 R-22

R-12 R-12

other Drop-in

Directions: Track all refrigerant usage. Place √ next to refrigerant recovered or installed. Use comment area to denote discrepancies between amount used and amount recovered. I.e. System leak, system flat.

Page 33: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Refrigerant Handling Process

Page 34: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Required Equipment • Over the next few months, each White Goods

technician will be supplied whatever equipment they’re missing to insure they all have:– Scale– R-134a Charging Cylinder– R-134a Manifold Gauge set– Recovery pump– 30 lb. recovery cylinder– Electronic Leak Detector– Hand valves (2)– Process tube adapter kit– Pinch off pliers– Recovery Bags (2)

Page 35: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Required Equipment • Over the next few months, each “specialty” technician will be supplied

whatever equipment they’re missing to insure they all have:– Scale– R-134a Charging Cylinder– R-134a Manifold Gauge Set– CFC Manifold Gauge Set– Micron Gauge– Recovery pump– Vacuum pump– 30 lb. recovery cylinder– Electronic Leak Detector– Hand valves (2)– Process tube adapter kit– Pinch off pliers– Recovery bags (2)

Page 36: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Required Equipment • Over the next few months, each PTAC** technician

will be supplied whatever equipment they’re missing to insure they all have:– Scale– CFC/HCFC Manifold– Vacuum Pump– Micron gauge– Recovery pump– 30 lb. recovery cylinder– Electronic Leak Detector– Hand valves (2)– Process tube adapter kit– Pinch off pliers

**PTAC techs who also work on White Goods will also carry R-134a refrigerant and related tools

Page 37: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Refrigerant Handling Process

• Virgin refrigerant– Technicians serviced by land based currier

will continue to receive new refrigerant from RPDC

– Technicians serviced by air currier must purchase refrigerant locally. (Use Refron facilities when possible to get quantity preferred pricing)

Page 38: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Refrigerant Handling Process

• Used refrigerant– Technicians serviced by land based currier

will return full cylinders to RPC• RPC will replace with empty, clean cylinder

– Technicians serviced by air currier must find local parts supplier that is willing to accept used refrigerant

• Work with virgin refrigerant supplier• Set up cylinder exchange program

Page 39: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Bag vs. Pump

• Use recovery pump and tank on all Major Brand refrigeration that – can be swept– uses R-134a

• Use the bag when servicing systems with– Burnouts– Unknown refrigerant– Drop-in refrigerant

Page 40: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Bag Handling Process

• Technicians serviced by land based currier – Return bags to RPC with tag identifying contents as

• Unknown refrigerant• R-134a Burnout• R-22, MP-39, etc

– RPC will replace with empty, clean bag

• Technicians serviced by air currier– Transfer contents of bag to a cylinder every night

• R-134a burnouts to R-134a tank• R-22 to R-22 tank• If enough R-410 is encountered, R-410 to its own cylinder• All other refrigerants to “mixed refrigerants” tank

Page 41: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

RPC refrigerant handling

• Each RPC responsible to – Maintain supply of empty tanks on hand to

replenish tanks when a full tank is received– Empty bags within 24 hours into appropriate

recovery tank• R-134a• R-22• R-410• All other refrigerants to “mixed refrigerants” tank

Page 42: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Approved Sealed System Repair Process

Page 43: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Why Change to Sweep

• Vacuum pumps require constant maintenance– Oil changes every 3 or 4 normal evacuations– After processing every burnout– Dirty oil renders pump incapable of pulling system to

required vacuum levels to assure complete dehydration

• Without ability to gauge dehydration level, there is no way to gauge how effective a vacuum was pulled, even with a well maintained vacuum pump

• Properly performed sweep superior to deep evacuation with poorly maintained pump or without measuring micron levels in system

Page 44: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Why is proper dehydration important?

0 PSIG

5 PSIG11.6

in Hg

29.92 in Hg

19.74

in Hg

Pressure Affect on Boiling Point of Water

34

84

134184

234

284

334

2 6 10 14 18 22 26 30 34

PSIG

Tem

per

atu

re

At m

os

ph

er i

c P

r es

su

r e

10 PSIG 15 PSIG1.4 PSIG

Unless system pressure is dropped to 300 microns or less, there is still water left in the system.

•In order for water to boil at normal room temperatures, system pressure must be dropped below 27” vacuum (About 3,000 Microns or less)

•Vacuum must be held over system until Micron levels drop below 300 microns

•Depending on pump conditions, proper dehydration could take several minutes or several hours.

Page 45: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

What happens when water is left in the system?

•Moisture and refrigerant create acids

•Acids eat away at compressor winding insulation

•Acids and oil create sludge which plugs cap tubes

Page 46: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Why is proper dehydration even more important with R-134a?• R-134a systems do not mix well with with mineral

oils and require the use of Ester oils• Ester oil are hygroscopic, meaning that they have a

great affinity for moisture (actually pull and absorb moisture out of the air)– Ester oils are made from acids that have been dehydrated – When exposed to atmospheric moisture, the oil actually pulls

vapor out of the air– The airborne moisture combines with the ester oil and

returns it to its original acidic state– Acids eat away at the compressor windings– Acids combine with R-134a to form salts and gels which can

plug the capillary tube.• Moisture in the system will eventually destroy the

compressor (not a matter of if but when)

Page 47: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Why Change to Sweep

• Sweep has been used in the industry for over 30 years (Maytag, GE, Whirlpool, Sears, Montgomery Wards and a slew of independents)

• Over the 30 year period, no conclusive proof has ever surfaced that sweep results in any more repeat failures than deep evacuation

• In fact, laboratory testing has shown that a properly performed sweep is superior to deep evac that is performed with poorly maintained vacuum pump or without an accurate method of measuring dehydration levels in system

Page 48: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Processing R-134a systems

• R-134a requires dedicated equipment to prevent cross contamination

• R-134a systems should not be open to the atmosphere for longer than 20 minutes (max)

• Verify compressor is nitrogen charged• Keep plugs in compressor until ready to make

final connections to system tubing

Page 49: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Processing R-134a systems

• Low side leaks– Find and repair leak– Replace compressor and dryer

• High side leaks– Find and repair leak– Replace drier

• Compressor burnout– Flush system– Replace compressor and drier

Page 50: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Processing R-134a systems

• Because of the small system charges of modern refrigerators, accurate charging is critical– On a 5 oz. system, overcharging by ½ oz.

results in 10% overcharge

• Because of energy and cooling capacity issues, it’s better to be slightly undercharged than to be overcharged by any amount.

Page 51: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Affect of Over/Undercharge on 950 BTU Compressor

Percent Correct Charge

1151101051009590858075

.5         600

.6         650

.7         700

.8         750

.9         800

1.0         850

1.2         900

1.3         950

1.4         1000

Amp Draw

BTU’s(Cooling Efficiency)

Page 52: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Problem with using a scale to charge small systems

• One quarter ounce resolution could undercharge or overcharge a system by as much as 10- 20% (depending on system charge)

• Unless scale is calibrated on a regular basis, there is no way to determine accuracy of scale

• Movement of the cylinder during charging changes the reading on the scale and could cause the final charge to be off by as much as 50%

Page 53: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Adding system charge

• Use Dial-a-Charge for all R-134a products.

• Charging scales should be used for – Drop-ins– R-22– To weigh recovery

cylinders if cylinder is not equipped with a ball float valve

Page 54: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Approved Sealed System Process

• Sweep charge is the only approved method of refrigerator and freezer system processing for most product lines– Exceptions

• PTACS• Samsung 4 drawer side by side

• Refrigerator technicians will need to turn in their vacuum pumpsNote: Vacuum pumps will be re-allocated to commercial and specialty techs

Page 55: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Sweep Charge

Page 56: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Sweep Charge Steps

1. Reconfirm need for the sealed system repair2. Verify that new compressor is nitrogen charged

(should hear a pop when line plug is removed from compressor)

3. Reinstall plugs on compressor to prevent excess air from entering system while old compressor is removed from the system

4. Attach temporary line taps to low side and drier process stubs

5. Attach gauges and recovery pump. Recover refrigerant per pump manufacturer’s recommended procedures

Page 57: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Sweep Charge Steps6. Cut out and remove old compressor

7. Install new drier

8. Install and plumb new compressor in place (keep compressor tubes plugged until ready to attach to system. This will assure that the system does not stay open longer than the recommended 20 minutes.)

9. Attach process stub adapters to new compressor and drier process stubs

10. Reattach gauges. High and low side hoses should have hand valves attached at end of each hose

Page 58: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Sweep Charge Steps

11. Fill Dial-a-Charge with system charge plus 8 oz. and heat refrigerant until pressure on Dial-a-Charge is 30 lbs. over ambient. Remember to capture refrigerant if bleeding of the cylinder is necessary (EPA reg)

12. Attach Dial-a-Charge to common hose on manifold gauge set.

13. Purge air out of all hoses and pre-charge high side hose with liquid.

14. Charge 4 oz of refrigerant into the system using the hand valve at the end of the high side hose to meter the refrigerant into system.

Page 59: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Sweep Charge Steps

15. Check all joints for leaks with a mirror and electronic leak detector

16. Turn compressor on and allow charge to circulate for 5 minutes

17. Close hand valve at drier18. Reattach pump and recover sweep charge as a

liquid from the drier process stub while the compressor is running.

19. Continue to run recovery pump until the system is down to the pump design pressure (usually around 20 inch vacuum on most pumps)

Page 60: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Sweep Charge Steps

20. Close hand valve at drier and turn off compressor and pump

21. Recheck pressure on Dial-a-Charge to make sure it is still at 30 lbs. over ambient. Reheat if necessary

22. Disconnect pump and reattach Dial-a-Charge to center hose of gauge set

23. Purge hoses and pre-charge high side hose with liquid

24. Using the hand valve, meter system charge into the system Important: Once the charge is added and the hand valve is closed, DO NOT reopen.

Page 61: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Sweep Charge Steps

25. Using pinch off pliers, pinch off the high side process stub.

26. Remove the hand valve and process tub adapter and braise the stub shut

27. Repeat process with low side process stub28. Check for low side leaks.29. Restart the compressor and check high side for

leaks.30. Check current draw and feel compressor discharge

for heat movement. Check air supply in freezer. If air is cold and current draw is normal, repair was successful.

Page 62: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

R-12 and Replacements

Page 63: Maytag Services Refrigerant Handling Standard Operating Procedures 1.

Processing R-12 Systems with Drop-in Refrigerants• MP-39 only approved R-12 substitute

– Hot Shot should not be purchased or used due to safety concerns (flammable- contains 6% methane)

• As with all blends, the sweep and final charges of MP39 must go into the system as a liquid– Requires that refrigerant be heated to 30 lb. over ambient

• If no heater blanket available for MP-39 tank, tank can be submersed into a partially filled 5 gallon bucket of warm water.

• Water should be no hotter than your skin can tolerate (125º F)– Charge must go into high side to prevent slugging of

compressor• Some older refrigerators have direct suction pumps and adding

liquid to low side could dump refrigerant into compression chamber