Adjustment Of Water Regulating Valve - Water-Cooled Model Only - Hoshizaki KMD-901MWH Service Manual

4) Attach a compressed air or carbon dioxide supply to the condenser water supply line
drain valve.
5) Open the water regulating valve by using a screwdriver to pry up on the spring retainer
underneath the spring. While holding the valve open, blow out the condenser using the
compressed air or carbon dioxide supply until water stops coming out.
6) Recover the refrigerant and store it in an approved container.
7) Disconnect the capillary tube at the condenser outlet.
8) Disconnect the flare-connections of the valve.
9) Remove the screws and the valve from the bracket.
10) Install the new valve.
11) Remove the drier, then place the new drier in position.
12) Braze all fittings while purging with nitrogen gas flowing at a pressure of 3 to 4 PSIG.
13) 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.
14) Evacuate the system, and charge it with refrigerant. See the nameplate for the required
refrigerant charge.
15) Connect the flare-connections.
16) Close the condenser water supply line drain valve, then open the condenser water
supply line shut-off valve.
17) Check for water leaks.
18) Replace the panels in their correct positions.
19) Turn on the power supply.
G. Adjustment of Water Regulating Valve - Water-Cooled Model Only
The water regulating valve (also called "water regulator") is factory-adjusted. No
adjustment is required under normal use. Adjust the water regulator, if necessary, using
the following procedures.
1) Prepare a thermometer to check the condenser drain temperature. Attach a pressure
gauge to the high-side line of the system.
2) Five minutes 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. 1. 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.
3) Check that the condenser drain temperature is stable.
Top View
Fig. 1
47
Adjustment
Screw
CW – Higher
CCW – Lower