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5.4 Refrigerant Handling
The use of recovery/recycling is required by the US Environmental Protection Agency (EPA) regu-
lations. Technicians who service and dispose of air conditioning and refrigeration equipment must
recover the refrigerant instead of venting to the atmosphere.
Except for extremely small releases of refrigerant such as those that occur when disconnecting
service hoses (diminutive release), a technician who knowing releases or vents refrigerant to the
atmosphere is in violation of these regulations. Freon purchasers must be certifi ed technicians and
have a valid EPA certifi cation card.
Warning! Pressure relief lines(s) must be vented to the atmosphere per the latest edition
of ASHRAE Standard 15 and/or any local building, fi re or mechanical codes.
This applies to all units with either sell and tube condensers or high pressure relief valve
options.
5.5 Important Refrigeration Components
5.5.1 Expansion Vale
Each refrigerant circuit has an adjustable thermo-expansion valve (TXV). They are factory adjusted
to their nominal rating. Any fi eld adjustment should be to “fi ne tune” a system that has been stabi-
lized and already has acceptable operating parameters.
5.5.2 High Pressure Cutout Switch
Each refrigeration circuit is protected by a high head pressure cutout switch with a manual reset
button. The switch is located near the compressor.
The pressure rating for R-407C systems is 400 PSIG.
The pressure rating for R-410A systems is 610 PSIG.
5.5.3 Low Pressure Cutout Switch
Each circuit includes a low pressure cutout switch with automatic reset. The switch is located near
the compressor section.
The pressure rating for R-407C systems is 28 PSIG.
The pressure rating for R-410A systems is 50 PSIG.
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