Hoshizaki KM-250BWF - Manual (Page 32)

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V. Removal and Replacement of Components
IMPORTANT
Ensure all components, fasteners and thumbscrews are securely in place
after the equipment is serviced.
IMPORTANT
1. 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.
2. 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. Service for Refrigerant Lines
[a] Refrigerant Recovery
The icemaker unit is provided with two refrigerant access valves
–one on the low-side
and one on the high-side lines. Recover the refrigerant from the access valves and store
it in an approved container. Do not discharge the refrigerant into the atmosphere.
Earlier models did not have high-side access valves on air-cooled and water-cooled
models. It may be necessary to install a high-side access valve to completely recover
the refrigerant.
[b] Evacuation and Recharge [R-404A]
1) Attach charging hoses, a service manifold and a vacuum pump to the system.
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. Never allow the oil in the vacuum pump to flow
backward.
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 service manifold.