Manitowoc QD0202A, Service Manual

Page: 124 / 175

Refrigeration System Section 7
7-12
Part No. 80-1100-3
3. Extremely Thin at Evaporator Inlet
There is no ice, or a considerable lack of ice formation
on the intlet of the evaporator (tubing inlet). Examples:
The ice at the outlet of the evaporator reaches 1/8" to
initiate a harvest, but there is no ice formation at all on
the intlet of the evaporator.
Figure 7-9. Extremely Thin Ice Formation at
Evaporator Inlet
4. Spotty Ice Formation
There are small sections on the evaporator where there
is no ice formation. This could be a single corner, or a
single spot in the middle of the evaporator. This is
generally caused by loss of heat transfer from the tubing
on the back side of the evaporator.
Figure 7-10. Spotty Ice Formation
5. No Ice Formation
The ice machine operates for an extended period, but
there is no ice formation at all on the evaporator.
Figure 7-11. Q1300/Q1600/Q1800 Evaporator Tubing
SV1575
OUTLET
INLET
ICE
SV1577
OUTLET
INLET
ICE
Important
The Q1300 Q1600 and Q1800 model machines
have left and right expansion valves and separate
evaporator circuits. These circuits operate
independently from each other. Therefore, one may
operate properly while the other is malfunctioning.
Example: If the left expansion valve is starving, it
may not affect the ice formation pattern on the entire
right side of the evaporator.
SV1571
OUTLET
INLET
OUTLET
INLET