Vogt TUBE-ICE P-118F, Service Manual

Page: 65 / 115

P118F Service Manual
TROUBLESHOOTING
1/6/09
8-5
SYMPTOM: Freeze-up due to ice failing to discharge.
POSSIBLE CAUSE POSSIBLE REMEDY
Insufficient heat for thawing because of low
condensing pressure, non-condensables
(usually air) in system, low refrigerant charge,
or thaw gas pressure switch adjusted too low. The head pressure should be maintained at
approximately 210 PSIG, which relates to
105F (37.8C). This is done by a water
regulating valve (water-cooled units) FIGURE
9-3A, Section 9, or a Fan cycling switch (air-
cooled units) FIGURE 9-3B, Section 9. If
non-condensables are present with the
refrigerant, the saturated temperature will not
relate to the pressure reading at the receiver.
The refrigerant level in the receiver should be
near the operating mark at the end of a
freezing cycle to provide enough volume for
harvesting. (1" = approx. 11 lbs. of R22).
Thawing time too short. Check the thaw timer (T) which should be
adjusted to allow all the ice to clear the cutter
and ice discharge opening with at least 30
seconds to spare.
Cutter or cutter disc does not turn. Check cutter reducer and drive gear for proper
operation and alignment. Check for broken
cutter disc or drive pin and replace as
necessary.
Ice backs up into cutter or discharge opening,
jamming cutter Ice mushy due to concentration of solids in the
water tank. Perform "Cleaning Procedure" and
check automatic and adjustable blowdown. If
the machine discharges ice into a chute, it
should slope at an angle of 30 degrees for
cylinder ice, an 45 degrees for crushed ice.
Check bin stat or level control to make sure it
will stop the machine before ice backs-up into
the cutter.
Extended freeze period. Check freezer pressure switch adjustment, see
FIGURE 9-1, Section 9, (Freezer Pressure
Switch) and TABLE 10-6, Section 10
(Operating Vitals).
Compressor not unloading. Check compressor amps during harvest. A
noticeable drop in amperage should occur.
Check unloader solenoid coil. If coil is okay,
replace unloader head assembly.