Flooding Expansion Valve Symptoms; Starving Expansion Valve/Low Refrigerant; Charge Symptoms; Overcharged System Symptoms - Manitowoc UDE065A Technician's Handbook

FLOODING EXPANSION VALVE SYMPTOMS

A flooding expansion valve will have discharge and suction
line temperatures 20°F (-7°C) lower than normal freeze
cycle temperatures. Normal suction line temperature and
low discharge line temperature DO NOT verify a flooding
valve. Both discharge line temperature and suction line
temperature must be low to verify a flooding expansion
valve. Ice fill pattern is thin on the left hand side of the
evaporator.

STARVING EXPANSION VALVE/LOW REFRIGERANT

CHARGE SYMPTOMS:

A. Ice Fill Pattern
• Thin on top two rows of the evaporator
• Thin on entire left side of the evaporator
• Thick on the bottom of the evaporator
B. Freeze time longer than normal
Diagnosis can be confirmed by adding installing a
temporary access valve and adding 2 oz (56.7 g) of
refrigerant: If the suction line temperature drops or the ice
fill pattern on the top two rows fills in, the ice machine is
low on refrigerant. Refer to charging procedures for access
valve installation/removal procedure.

OVERCHARGED SYSTEM SYMPTOMS

Suction line temperature will be slightly low during freeze
cycle 5°F (-15°C). Discharge line temperature is normal.
Actual amperage readings will be higher than nameplate
rating.
Part Number 000014797 Rev02 05/18 139