Hoshizaki 73202 Ice Maker User Manual


 
37
1. Refrigerant Recovery
This icemaker is provided with refrigerant access valves. Using proper refrigerant
practices, recover the refrigerant from the service valves and store it in an approved
container. Do not discharge the refrigerant into the atmosphere.
2. Brazing
WARNING
• R-404A itself is not ammable at atmospheric pressure and temperatures up to
176°F (80°C).
• R-404A itself is not explosive or poisonous. However, when exposed to high
temperatures (open ames), R-404A can be decomposed to form hydrouoric
acid and carbonyl uoride both of which are hazardous.
• 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 (140 PSIG). Do not use R-404A as a mixture with
pressurized air for leak testing.
1) Braze all ttings while purging with nitrogen gas owing at a pressure of 3 to 4 PSIG.
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
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-404A as a mixture with
pressurized air for leak testing.
3. Evacuation and Recharge (R-404A)
1) Attach a vacuum pump to the system. Be sure to connect charging hoses to both high
and low-side access valves.
IMPORTANT
The vacuum level and vacuum pump may be the same as those for current
refrigerants. However, the rubber hose and gauge manifold to be used for
evacuation and refrigerant charge should be exclusively for POE oils.
2) Turn on the vacuum pump. Open the gauge manifold valves. Never allow the oil in the
vacuum pump to ow backwards.
3) Allow the vacuum pump to pull down to a 29.9" Hg vacuum. Evacuating period depends
on pump capacity.