Hoshizaki MRH KM-600MAH KM-650MAH, MWH KM-515MAH, MRH/3, MWH(-M) Component Service Information

B. Component Service Information

NOTICE

When replacing a component listed below, see the notes to help ensure proper operation.

Component	Notes
Compressor	1 phase: Install a new start capacitor, run capacitor, and start relay.
	3 phase: Install a new magnetic contactor.
Thermostatic	• Attach the thermostatic expansion valve bulb to the suction line in the same location as
Expansion Valves	the previous bulb.
	• The bulb should be between the 10 and 2 o'clock positions on the tube.
	• Secure the bulb with the clamp and holder, then insulate it.
Hot Gas Valves	• Replace the strainer if applicable.
Liquid Line	• Use copper tube of the same diameter and length when replacing valve lines.
Valves
Fan Motors	Install a new capacitor.
Pump Motor	Install a new capacitor.
Thermistor	• Attach the new thermistor to the suction line in the same location as the previous
	thermistor.
	• The thermistor should be at the 12 o'clock position on the tube.
	• Smoothly fill the recessed area of the thermistor holder with high thermal conductive
	type sealant. Hoshizaki America part number 4A0683-01 (Silicone Heat Sink Compound
	10-8108 manufactured by GC Electronics), KE-4560 RTV (manufactured by ShinEtsu
	Silicones), or equivalent are recommended.
	• Secure the thermistor with the holder, then insulate it.
	• Be very careful to prevent damage to the leads.
KM-650MWH-M	Tighten the water regulating valve flare nut to a torque of 39.8 ft-lb/53.9 N·m.
Water Regulating
Valve

C. Water Regulating Valve Adjustment (water-cooled model)

The water regulating valve is factory set, and generally no adjustment is required. However, when necessary, adjust the water regulator using the following procedure.

1)Prepare a thermometer to check the condenser drain temperature. Attach a pressure gauge to the high-side line of the system.

2)5 min. after a freeze cycle starts, confirm that the thermometer reads 104°F to 115°F (40°C to 46°C). If it does not, rotate the adjustment screw by using a flat blade screwdriver until the temperature is in the proper range. See Fig. 5. Next, check that the reference pressure is in the range indicated in the Head Pressure table in the Performance Data section. If it is not in the proper range, verify the refrigerant charge.

Adjustment Screw

CW – Higher

CCW – Lower

Top View Fig. 5

3) Check that the condenser drain temperature is stable.

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