R-410A Sealed System Repair - Friedrich VERT-I-PAK VHA09K25RTQ Service Manual

R-410A SEALED SYSTEM REPAIR

Use approved standard refrigerant recovering procedures and equipment to relieve high pressure before opening system for repair.
Do not allow liquid refrigerant to contact skin. Direct contact with liquid refrigerant can result in minor to moderate injury.
Be extremely careful when using an oxy-acetylene torch. Direct contact with the torch's flame or hot surfaces can cause serious burns.
Make certain to protect personal and surrounding property with fire proof materials and have a fire extinguisher at hand while using a torch.
Provide adequate ventilation to vent off toxic fumes, and work with a qualified assistant whenever possible.
.
Always use a pressure regulator when using dry nitrogen to test the sealed refrigeration system for leaks, flushing etc.
Refrigeration system under high pressure
O
service this equipment.
R410A systems operate at higher pressures than
R22 equipment. Appropriate safe service and
handling practices must be used.
Only use gauge sets designed for use with R410A.
Do not use standard R22 gauge sets.
The following is a list of important considerations when
working with R-410A equipment
1.
R-410A pressure is approximately 60% higher than R-22
pressure.
2. R-410A cylinders must not be allowed to exceed 125 F, they may
leak or rupture.
3. R-410A must never be pressurized with a mixture of air, it may
become
flammable.
4. Servicing equipment and components must be specifically
designed for use with R-410A and dedicated to prevent
contamination.
5. Manifold sets must be equipped with gauges capable of reading
750 psig (high side) and 200 psig (low side), with a 500-psig low-
side retard.
6. Gauge hoses must have a minimum 750-psig service pressure
rating
7. Recovery cylinders must have a minimum service pressure
rating of 400 psig, (DOT 4BA400 and DOT BW400 approved
cylinders).
8. POE (Polyol-Ester) lubricants must be used with R-410A
equipment.
9. To prevent moisture absorption and lubricant contamination, do
not leave the refrigeration system open to the atmosphere longer
than 1 hour.
10. Weigh-in the refrigerant charge into the high side of the system.
11. Introduce liquid refrigerant charge into the high side of the
system.
12. For low side pressure charging of R-410A, use a charging
adaptor.
13. Use industry standard R-410A filter dryers.
48
WARNING
WARNING
EPA 608 Warning:
It is a violation of the environmental Protection
Agency, Clause 608A, to service refrigeration
systems without proper certi cation
EQUIPMENT REQUIRED:
1. Electrical Multimeter
2. E.P.A. Approved Refrigerant Recovery System
3. Vacuum Pump (capable of 200 microns or less vacuum.)
4. Acetylene torch.
5. Electronic Halogen Leak Detector capable of detecting HFC
(Hydrofluorocarbon) refrigerants.
6. R410A Refrigerant Manifold
7. 1/4" Braze-type Access Ports
8. Pinch Tool
9. Digital Refrigerant Scale
10. Vacuum Gauge - (0 - 1000 microns)
11. Facilities for flowing nitrogen through refrigeration tubing
during all brazing processes.
EQUIPMENT MUST BE CAPABLE OF:
1. Recovering refrigerant to EPA required levels.
2. Evacuation from both the high side and low side of the system
simultaneously.
3. Introducing refrigerant charge into high side of the system.
4. Accurately weighing the refrigerant charge introduced into the
system.
WARNING