Sub-Zero 700-3 BASE, Technical & Service Manual, Page: 42 / 114

Sealed System Information
Integrated
(700-
3
BASE)
Series
4-2
#3758424 - Revision B - December, 2005
HFC-134a REFRIGERANT SERVICE INFORMATION
The sealed systems contain HFC-134a refrigerant. This section provides some general rules for working with 134a,
and explains procedures to be followed while servicing the sealed system. This is followed by diagrams which illus-
trate sealed system operation, then model-specific refrigerant flow diagrams.
134a refrigerant requires Synthetic Ester oil in the compressor, and does not tolerate contamination from
other refrigerants, moisture, petroleum-based lubricants, silicone lubricants, cleaning compounds, rust
inhibitors, leak detection dyes, or any other type of additive.
General Rules for Working with 134a Refrigerant
• Use equipment dedicated to 134a sealed system service only.
• Use only 134a refrigerant for back-flushing and sweep charging.
• Always replace the filter-drier when servicing the sealed system.
• The filter-drier must be cut from the sealed system. Never un-braze the drier as the heat will drive moisture
back into the sealed system.
• Do not leave sealed system nor replacement compressor open to the atmosphere for more than 10 minutes.
• When the rubber plugs are pulled from the service compressor, a release of pressure should be heard. If no
release of pressure is heard, do not use the compressor.
• Use ONLY virgin 134a refrigerant when recharging the sealed system.