Hoshizaki KM-320MAH, KM-320MWH service manual Removal and Replacement of Compressor

C. 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 a pressure of 3 to 4 PSIG.

13)Install a new drier.

14)Check for leaks using nitrogen gas (140 PSIG) and soap bubbles.

15)Evacuate the system and charge it with refrigerant. See the nameplate for the required refrigerant charge.

16)Connect the terminals and replace the terminal cover in its correct position.

17)Replace the panels in their correct positions.

18)Turn on the power supply.

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