Vogt HEC-10, Service Manual

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HEC-Series Service Manual
TROUBLESHOOTING
10/21/01
8-2
Symptom: Freeze up due to extended freezing period.
Check for Fault #15, Long Freeze Cycle (see note below)
Possible Cause Possible Remedy
Freezer pressure switch setting too low. See Freezer Pressure Switches, Section 9
FIGURE 9-1, and Operating Vitals, Section 11,
TABLE 11-2.
Warm condenser water entering water tank (7)
through overflow connection (40). WATER
COOLED UNITS Pipe water outlet (24) and drain (25) separately
to floor drain. See Section 3, Water Supply
and Drains.
Drain valve (39) from water pan open or
leaking. Close valve or repair.
Solenoid valve (18) may be by-passing hot
refrigerant gas into freezer (2) during the freeze
mode. Clean or replace solenoid valve. Check manual
opening stem which should be at “All In”
position. See Solenoid Valve, Section 9,
FIGURE 9-13.
Make-up water float valve (12) stuck open or
adjusted too high. Check operation of float valve and replace if
necessary. See Float Valve (Make-Up Water),
Section 9.
Low refrigerant charge (usually insufficient
warm gas for harvesting). See Refrigerant Charge. Check system for
leaks before adding refrigerant, Section 9.
Expansion valve (17) overfeeding. See Expansion Valve, Section 9.
PLC malfunction Check PLC power supply and fuses. Also
check for loose wire connections. Replace
PLC if defective.
A machine Fault #15 has occurred. Enter the troubleshoot mode and identify the
last occurring “fault”. See Fault Identity,
Section 6, TABLE 6-2.