Vogt P118F/HE100, Service Manual

Page: 70 / 126

05TA Service Manual
TROUBLESHOOTING
7/19/13
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 to initiate startup in a
thawing cycle.
Compressor motor overload (CM-OL) trips.
Note: Used on 4D & 6D compressors without
Coresense. All 3D compressor have
Internal Line Break for overcurrent
protection.
Coresense on 4D compressors combines
overcurrent & oil pressure protection.
(after March 2011)
Check for a loose connection on 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 compressors without
Coresense and 3D compressors (with line
break protection) will reset automatically after
the motor has cooled sufficiently.
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 reset breaker.
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 9-2, Section 9,
(High/Low Pressure Switch).