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1. Refrigerant Recovery
No refrigerant access valves are provided on this appliance. Using proper refrigerant
practices, utilize a temporary tap-line valve on the high side to recover the refrigerant.
Store the refrigerant in an approved container. Do not discharge the refrigerant into
the atmosphere. After recovery is complete, replace the tap-line valve with a proper,
permanent access valve.
2. Brazing
WARNING
• R-134a itself is not À ammable at atmospheric pressure and temperatures up to
176°F (80°C).
• R-134a itself is not explosive or poisonous. However, when exposed to high
temperatures (open À ames), R-404A can be decomposed to form hydroÀ uoric
acid and carbonyl À uoride both of which are hazardous.
• Do not use silver alloy or copper alloy containing arsenic.
1) Braze all ¿ ttings while purging with nitrogen gas À owing at a pressure of 3 to 4
PSIG.
Note: Because the pipes in the evaporator case are specially coated to resist
corrosion, it is important to make connections outside the evaporator case
when possible. If it is necessary to braze inside the evaporator case, use
sandpaper to remove the coating from the brazing connections before
unbrazing the components.
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
À ow.
• 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).
2) 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 (140 PSIG). Do not use R-134a as a mixture with
pressurized air for leak testing.
3. Evacuation and Recharge (R-134a)
1) Attach a vacuum pump to the system. Be sure the high-side charging hose is
connected to the ¿ eld-installed high-side access valve.
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