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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 low-side refrigerant 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 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 low-side valve and high-side valve on the gauge manifold.
5) Disconnect the gauge manifold hose from the vacuum pump and attach it to a
refrigerant service cylinder. Remember to loosen the connection and purge the air
from the hose. See the nameplate on the icemaker for the required refrigerant charge.
Hoshizaki recommends only virgin refrigerant or reclaimed refrigerant which meets
ARI Standard 700 (latest edition) be used.
6) A liquid charge is required when charging an R-404A system (to prevent fractionation).
Place the service cylinder on the scales; if the service cylinder is not equipped with
a dip tube, invert the service cylinder, then place it on the scales. Open the high-side
valve on the gauge manifold.
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 low-side.
NOTICE!
To
prevent compressor damage, use a throttling valve or liquid dispensing device
to add the remaining liquid charge through the low-side refrigerant shutoff valve
with the icemaker running.
9) Close the high and low-side gauge manifold valves, then disconnect the gauge manifold
hoses.
10) Cap the refrigerant access valves to prevent a possible leak.
