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4) Close the low-side valve and high-side valve on the service 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 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 recommended for charging an R-134a system. Invert the service
cylinder and place it on scales. Open the high-side valve on the gauge manifold valve.
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. Use a
throttling valve or liquid dispensing device to add the remaining liquid charge through
the low-side access port with the unit running.
9) Close gauge manifold valves and disconnect the hoses and service manifold.
10) Cap the access valves to prevent a possible leak.
B. Removal and Replacement of Compressor
CAUTION
1. Always install a new drier every time the sealed refrigeration system is
opened.
2. 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.
3. When brazing, protect the drier by using a wet cloth to prevent the drier from
overheating. Do not allow the drier to exceed 250°F (121°C).
Note: Due to the ability of the POE oil in the compressor to absorb moisture quickly,
the compressor must not be opened more than 15 minutes for replacement or
service. Do not mix lubricants of different compressors even if both are charged
with R-134a, except when they use the same lubricant.
1) Raise the front panel. Then, move the power switch to the "OFF" position and unplug
the unit.
2) Remove the panels.
3) Recover the refrigerant and store it in an approved container. See "V.A. Service for
Refrigerant Lines."
4) Loosen the 2 screws securing the compressor electronic unit to the compressor. See
Fig. 3. Remove the electronic unit from the compressor.
5) Remove the discharge and suction pipes.
6) Remove the hold-down bolts, washers, and rubber grommets.
7) Remove the compressor.
8) Place the new compressor in position and secure it using the grommets, washers and
bolts.
