Manitowoc indigo series Technician's Handbook page 153

Final Analysis - Self-contained Air, Water & Remote
Condenser Models
The column with the highest number of Checkmarks
identifies the refrigeration problem.
COLUMN 1 - HARVEST VALVE LEAKING
Replace the valve as required.
COLUMN 2 - LOW CHARGE/TXV STARVING
Normally, a starving expansion valve only affects the
freeze cycle pressures, not the harvest cycle pressures. A
low refrigerant charge normally affects both pressures.
Verify the ice machine is not low on charge before
replacing an expansion valve.
1. Add refrigerant charge to verify a low charge (air and
water self-contained only). Do not add more than
30% of nameplate refrigerant charge. If the problem
is corrected, the ice machine is low on charge.
*Do not add charge to remote models. The
symptoms of a remote low on charge will result in a
safety limit #1 in cool ambient temperatures. Check
the liquid line temperature at the ice machine. The
liquid line will be hot with a normal or below normal
head pressure in freeze when the ice machine is low
on refrigerant.
2. Find the refrigerant leak. The ice machine must
operate with the nameplate charge. If the leak
cannot be found, proper refrigerant procedures
must still be followed Change the liquid line drier.
Then, evacuate and weigh in the proper charge.
3. If the problem is not corrected by adding charge, the
expansion valve is faulty.
Part Number STH025 11/16 153