Important Notes For Component Replacement - Hoshizaki DCM-751BAH Service Manual

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 inside the appliance 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 required for charging an R-404A system (to prevent fractionation).
Place the service cylinder on the scales: if the service cylinder is not equipped with
a dip tube, invert the service cylinder, then place it on the scales. Open the high-side
valve on the gauge manifold.
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.
NOTICE! To prevent compressor damage, use a throttling valve or liquid
dispensing device to add the remaining liquid charge through the low-side
service valve with the appliance running.
9) Close the high and low-side gauge manifold valves, then disconnect the gauge manifold
hoses.
10) Cap the access valves to prevent a possible leak.
B. Important Notes for Component Replacement
When replacing a component listed below, see the notes to help ensure proper
operation. See Fig. 14.
Component
Compressor • Install a new drier, start capacitor, run capacitor, and start relay.
Thermostatic • Install a new drier.
Expansion Valve
• Attach the thermostatic expansion valve bulb to the suction line in the same location as
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.
Fan Motor • Install a new fan motor capacitor.
Upper and • Inspect the upper bearing for wear. See "IV.C.1. Upper Bearing Wear Check." Replace if
necessary.
Lower Bearings
• When replacing the upper bearing it is advised to also change the lower bearing at the
same time.
Evaporator • Install a new drier.
• Inspect the mechanical seal and O-ring prior to installing the new evaporator. If worn,
cracked, or scratched, the mechanical seal should also be replaced.
Gear Motor • Install a new gear motor capacitor.
Extruding Head • Extruding head allen head cap screws (with seals) are not reusable. New allen head cap
screws (with seals) must be used.
Bolts
NOTICE
Evaporator Assembly Components. See Fig. 14.
Notes
42