Service Manual

24
WARNING
• R-134a is not flammable at atmospheric pressure and temperatures up to 176°F
(80°C).
• R-
134a is not explosive or poisonous. However, when exposed to high
temperatures (open flames), R-134a can be decomposed to form hydrofluoric
acid and carbonyl fluoride both of which are hazardous.
• For brazing R290 system must be purge with nitrogen for couple minutes before
and during brazing process.
• Do not use silver alloy or copper alloy containing arsenic.
• Use an electronic leak detector or soap bubbles to check for leaks. Add a trace
of refrigerant to the system (if using an electronic leak detector), and then raise
the pressure using nitrogen gas (200PSIG). Do not use R-134a, R-404A or R290
as a mixture with pressurized air for leak testing.
NOTICE
• Always install a new drier every time the sealed refrigeration system is opened.
• Do not replace the drier until after all other repair or replacement has been
made. Install the new drier with the arrow on the drier in the direction of the
refrigerant flow.
• When brazing, protect the drier by using a wet cloth to prevent the drier from
overheating. Do not allow the drier to exceed 250°F (121°C).
1. Refrigerant Recovery
The appliance is provided with refrigerant access valves. Using proper refrigerant practices
recover the refrigerant from the access valves and store it in an approved container. Do not
discharge the refrigerant into the atmosphere.
The gas R290 is not necessary recover; can be in a well ventilated area with no source of
ignition.
2. Brazing
1) Braze all fittings while purging with nitrogen gas flowing at a pressure of 3 to 4
PSIG.