Hoshizaki KM-501MAH User Manual

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Ensure all components, fasteners and thumbscrews are securely in place after 
the equipment is serviced.

. The Polyol Ester (POE) oils used in R-404A units can absorb moisture 

quickly. Therefore it is important to prevent moisture from entering the system 
when replacing or servicing parts.

. Always install a new filter drier every time the sealed refrigeration system is 

opened.

3. Do not leave the system open for longer than 5 minutes when replacing or 

servicing parts.

1. Refrigerant Recovery
The icemaker unit is provided with two refrigerant access valves–one on the low-side and 
one on the high-side line. Using proper refrigerant practices recover the refrigerant from the 
access valves and store it in an approved container. Do not discharge the refrigerant into 
the atmosphere.

) Attach charging hoses, a service manifold and a vacuum pump to the system. Be sure 

to connect charging hoses to both high and low-side access valves.

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. 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 and high-side valve on the service manifold.
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. 700-88 be used.

6) A liquid charge is recommended for charging an R-404A system. Invert the service 

cylinder. Open the high-side, service manifold valve.

7) Allow the system to charge with liquid until the pressures balance.