1)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.
2)Braze all fittings while purging with nitrogen gas flowing at a pressure of 3 to 4 PSIG.
3)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
3.Evacuation and Recharge (R-404A)
1)Attach a vacuum pump to the system. Be sure to connect the charging hoses to both high and
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 service manifold valves. Never allow the oil in the vacuum pump to flow backwards.
3)Allow the vacuum pump to pull down to a 29.9" Hg vacuum. Evacuating period depends on pump capacity.
4)Close the
5)Disconnect the vacuum pump and attach a refrigerant service cylinder to the high‑side line. Remember to loosen the connection and purge the air from the hose. See the nameplate for the required refrigerant charge. Hoshizaki recommends only virgin refrigerant or reclaimed refrigerant which meets ARI Standard No.
6)A liquid charge is recommended for charging an
7)Allow the system to charge with liquid until the proper charge weight is met.
8)If necessary, add any remaining charge to the system through the
9)Close the service manifold valves and disconnect the service manifold hoses.
10)Cap the access valves to prevent a possible leak.
47