Vogt HEC-10, Service Manual

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HEC-Series Service Manual
SERVICE OPERATIONS
10/21/01
9-6
FIGURE 9-3. Water Regulating Valve. FIGURE 9-4. Condenser Fan Switch.
Water-Cooled Units. A water regulating valve (FIGURES 1-3B & 9-3) located in the condenser
water inlet line is used to control the water flow through the condenser. This valve should be
adjusted to maintain a head pressure of 190-210 psig. Increasing the water flow lowers the head
pressure and decreasing the water flow raises the head pressure. The valve is adjusted during the
factory test.
Compressor Crankcase Heater. When electrical power is supplied to terminals L1, L2 & L3 of the
control panel, the crankcase heater is energized when the machine is not operating.
PLC Fuses. Six PLC output fuses located in the control panel provide the PLC with short circuit
protection. If any of the 2 amp (PLC output) fuses FU0-FU5 are blown, they must be replaced for
that component to function. Fuse Part #12A-7504E23000000.
! CAUTION !
In case of a power interruption or outage, be sure the compressor crankcase
is warm and there is no liquid refrigerant in the crankcase prior to restarting
the machine manually (except for Scroll compressor)
! CAUTION !
Two control circuit fuses (FU100 and FU200) located in the switch box (FIGURE 6-2) protects the
compressor crankcase heater as well as the control circuit.
If either of these two fuses “blow” for any reason, they must be replaced before the crankcase heater
is energized and the machine will operate. Fuse Part #12A-7504E10000000.
Ice Bin Thermostat(s) Adjustments. The ice bin thermostats (FIGURES 6-1 & 9-5) are set prior
to shipment. However, a MINOR adjustment may be necessary after installation due to local
conditions. The following procedure should be followed for initially setting or maintaining
adjustments to the ice bin thermostat.