Vogt P18FXT, Service Manual

Page: 72 / 124

10TA Service Manual
TROUBLESHOOTING
4/23/14
8-2
SYMPTOM:
Machine won't run.
POSSIBLE CAUSE POSSIBLE REMEDY
Power failure ++ Intermittent power
interruption Check electrical fused disconnect or circuit
breaker supplying power to the machine. If
power has been off, make sure the compressor
crankcase heater is energized, the crankcase is
warm, and there is no liquid refrigerant in the
crankcase prior to running the machine. Push the
"Start" button which will initiate startup in a
thawing cycle.
Compressor motor overload (CMS-OL) trips.
Note: Used on 4D & 6D compressors without
Coresense. All 3D compressor have
Internal Line Break for overcurrent
protection.
Coresense on 4D & 6D compressors
combines overcurrent & oil pressure
protection. (after March 2011)
Check for a loose connection on all motor
contactor and compressor terminals, which could
have caused excessive amp draw. Check
amperage, power supply, and head pressure.
Excessive temperature may be caused by gas
leakage between suction and discharge port of
the compressor. Check for broken cylinder head
gasket or valve assemblies. Replace broken or
defective parts. Restart the machine and check
motor amps and temperature of compressor body.
Note: Switch on 4D & 6D compressors without
Coresense and 3D compressors (with line break
protection) will reset automatically after the
motor has cooled sufficiently.
Compressor cylinder head temperature switch
trips. The thermal switch will reset automatically after
the motor has cooled sufficiently. Excessive
temperature may be caused by gas leakage
between suction and discharge port of the
compressor. Check for broken cylinder head
gasket or valve assemblies. Replace broken or
defective parts. Restart the machine and check
motor amps and temperature of compressor body.
3.0 amp circuit breaker (CB) in the control
panel tripped. Check compressor crankcase heater, coils of
relays, contactors, starters, solenoid valves, and
thawing timer for a ground. Repair or replace
any defective part, and replace fuse. Make sure
there is no liquid refrigerant in the compressor
crankcase prior to re-starting the machine.
High/Low safety pressure switch tripped. If the machine stops by low pressure cut-out, the
switch will reset automatically when the pressure
raises to the " cut-in " setting. If it stops by high
pressure cut-out, the switch will have to be
manually reset after the pressure drops below the
" cut-in " setting. Check switch settings and push
the "Start" push button to start the machine in a
thawing cycle. Check the head pressure during
the next freeze cycle. See FIGURE 9-4, Section
9, (High/Low Pressure Switch).