10TA Service Manual
TROUBLESHOOTING
4/23/14
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 for R-22 or 250 PSIG
for R404a, which relates to 105F (37.8C). This
is done by a water regulating valve (water-
cooled units) FIGURE 9-5A, Section 9, or a
Fan cycling switch (air-cooled units) FIGURE
9-5B, 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 or R404a).
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, and 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 9-3, Section 9, (Freezer Pressure
Switch) and TABLE 11-6, Section 11
(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.
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