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129
Refrigeration Maintenance
Introduction
The following procedures involve servicing the
refrigeration system. Some of these service
procedures are regulated by Federal, and in some
cases, by State and Local laws.
NOTE: All regulated refrigeration service
procedures must be performed by an EPA
certified technician, using approved equipment
and complying with all Federal, State and Local
laws.
Use the Correct Tools
Use the Correct Vacuum Pump
A two-stage (refer to Tool Catalog), three-stage or
five-stage pump is recommended for evacuation.
Purging the system with dry nitrogen is
recommended before evacuation. Because
residual refrigerant may be present in used
vacuum pumps, a new vacuum pump should be
used and dedicated strictly as an R-404a
refrigerant pump. Use only recommended vacuum
pump oils and change oil after every major
evacuation. Because vacuum pump oils are highly
refined to obtain low vacuums, failure to follow
these recommendations may result in acidic
conditions that will destroy the pump.
Use Filters and Cartridges
Cleanup devices such as suction line filters and
compressor oil filters may be used if they are
properly cleaned and new filters and cartridges are
used. All standard petroleum and synthetic
compressor oils must be removed to prevent the
contamination of R-404A systems.
Use the Correct Refrigerant
Recovery Equipment
Use only refrigerant recovery equipment
approved for and dedicated to R-404A recovery.
Detecting Leaks
Leaks can be detected with the use of soap
bubbles and with Halogen leak detectors such as
model H10G or model H10N (portable).
Locating Special Service
Fittings
Special fittings are used on HFC systems to
prevent mixing of non-HFC refrigerants in HFC
units. These fittings are located in three places on
MAGNUM refrigeration systems:
•
Low side near the compressor suction service
valve (or suction adapter)
•
High side near the compressor discharge
service valve (or discharge manifold)
•
Receiver Tank
CAUTION: Use only those service tools
certified for and dedicated to R-404A
refrigerant and Polyol Ester based
compressor oils (i.e., vacuum pump,
refrigerant recovery equipment, gauge
hoses, and gauge manifold set). Residual
non-HFC refrigerants or non-Ester based
oils will contaminate HFC systems.
1.
Internal Threads for Cap
2.
High Pressure Fitting
3.
Low Pressure Fitting
Figure 74: Service Fittings Specifications
AXA0175
Summary of Contents for 098916
Page 5: ......
Page 11: ...Table of Contents 10...
Page 19: ...Service Guide 18...
Page 28: ...Specifications 27 Figure 2 Physical Specifications AMA313...
Page 41: ...Unit Description Features Options 40...
Page 105: ...Operating Instructions 104...
Page 155: ...Servicing The Unit 154...
Page 187: ...Index 186...
Page 189: ...Wiring and Schematic Diagrams Index 188...
Page 190: ...189 Wiring Schematic...
Page 191: ...190 Wiring Diagram Page 1 of 2...
Page 192: ...191 Wiring Diagram Page 2 of 2...