Hoshizaki KM-900MAH, Service Manual

Page: 55 / 73

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3. REMOVAL AND REPLACEMENT OF COMPRESSOR
IMPORTANT
Always install a new Drier every time the sealed refrigeration system is opened.
Do not replace the Drier until after all other repair or replacement has been
made.
Note: When replacing a Compressor with a defective winding, be sure to install the new Start
Capacitor and Start Relay supplied with the replacement Compressor. 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-404A, except when
they use the same lubricant.
1) Turn off the power supply.
2) Remove the 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 and Suction Pipes using brazing equipment.
6) Remove the Hold-down Bolts, Washers and Rubber Grommets.
7) Slide and remove the Compressor. Unpack the new Compressor package. Install the
new Compressor.
8) Attach the Rubber Grommets of the prior Compressor.
9) Sandpaper the Suction, Discharge and Process Pipes.
10) Place the Compressor in position, and secure it using the Bolts and Washers.
11) Remove plugs from the Suction, Discharge and Process Pipes.
12) Braze the Process, Suction and Discharge lines (Do not change this order), while purging
with nitrogen gas flowing at the pressure 3-4 PSIG.
13) Install the new Filter Drier.
14) Check for leaks using nitrogen gas (140 PSIG) and soap bubbles.