Evacuation And Recharge (R-404A) - Hoshizaki F-330BAH Service Manual

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.
) Braze all fittings while purging with nitrogen gas flowing at a pressure of 3 to 4 PSIG.
3) Check for leaks using nitrogen gas (140 PSIG) and soap bubbles. 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.
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.
) Turn on the vacuum pump, then open the low-side valve on the service manifold. Never
allow the oil in the vacuum pump to flow backward.
3) Allow the vacuum pump to pull down to a 9.9" Hg vacuum. Evacuating period depends
on pump capacity.
4) Close the low-side valve on the service manifold.
5) Disconnect the vacuum pump, and attach a refrigerant service cylinder to the service
manifold. 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. 700-88 be used.
6) A liquid charge is recommended for charging an R-404A system. Invert the service
cylinder and place it on scales. Open the low-side valve on the service manifold.
7) Allow the system to charge with liquid until the proper charge weight is met.
8) If necessary, use a throttling valve or liquid dispensing device to add any remaining
liquid charge with the unit running.
9) Close the refrigerant access valve and disconnect the service manifold hose.
10) Cap the access valve to prevent a possible leak.
IMPORTANT
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