Hoshizaki HPR100A, Service Manual

Page: 47 / 66

47
C. 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).
4. Recover the refrigerant when replacing the compressor. Do not discharge
the refrigerant into the atmosphere.
5. The compressor may be replaced without removing the refrigeration
cartridge. If removing the refrigeration cartridge, see "IV.B. Removal and
Replacement of Refrigeration Cartridge."
Note: When replacing a compressor with a defective winding, be sure to install a new
start capacitor, overload and start relay. 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 the same type of refrigerant,
except when they use the same lubricant.
1) Move the power switch to the "OFF" position, then unplug the unit.
2) Remove the front, left side, and rear panels.
3) Recover the refrigerant and store it in an approved container.
4) Remove the terminal cover on the compressor and disconnect the compressor wiring.
5) Remove the discharge, process, and suction pipes.
6) Remove the hold-down bolts, washers, rubber grommets, and sleeves.
7) Remove the compressor. Unpack the new compressor. Attach the rubber grommets
and sleeves of the prior compressor.
8) Place the new compressor in position, and secure it using the bolts and washers.
9) Remove the drier, then place the new drier in position.
10) Remove the plugs from the suction, discharge, and process pipes.
11) Braze all fittings while purging with nitrogen gas flowing at a pressure of 3 to 4 PSIG.
12) Use an electronic leak detector or soap bubbles to check for leaks. Add a trace of
refrigerant to the system (if using an electronic leak detector), and then raise the
pressure using nitrogen gas (140 PSIG). DO NOT use R-404A as a mixture with
pressurized air for leak testing.
13) Evacuate the system, and charge it with refrigerant; see the nameplate for the required
refrigerant charge.
14) Connect the compressor terminals, then replace the terminal cover in its correct
position.