Manitowoc Ice QM45 Series Safety Limit #1, Safety Limit #2, Before Calling for Service, Section

Models: QM45 Series

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Safety Limit #1

Before Calling for Service

Section 5

Safety Limit #1

Freeze time exceeds 60 minutes for 3 consecutive freeze cycles.

Possible Cause

Improper installation

Water system

Electrical system

Restricted condenser air flow (air-cooled models)

Refrigeration system

Check/Correct

See “Installation Instructions” Section two of this manual

Low water pressure (20 psi minimum.)

High water pressure (80 psi maximum.)

High water temperature (90°F/32.2°C maximum.)

Clogged water distribution tube

Dirty/defective water float valve

Loss of water from sump area

Defective water pump

Ice thickness probe out of adjustment

Harvest cycle not initiated electrically

Relay not energizing

Compressor electrically non-operational

High inlet air temperature (110°F/43.3°C maximum.)

Condenser discharge air recirculation

Dirty condenser filter

Dirty condenser fins

Defective fan cycling control

Defective fan motor

Non-Manitowoc components

Improper refrigerant charge

Defective hot gas valve

Defective compressor

TXV starving or flooding (check insulation and bulb mounting)

Non-condensables in refrigeration system

Plugged or restricted high side refrigerant lines or component

Safety Limit #2

Harvest time exceeds 3.5 minutes for 3 consecutive harvest cycles.

Possible Cause

Improper installation

Water system

Electrical system

Refrigeration system

Check/Correct

See “Installation Instructions” Section two of this manual

Water area (evaporator) dirty

Water freezing behind evaporator

Low water pressure (20 psi min.)

Loss of water from sump area

Clogged water distribution tube

Dirty/defective water float valve

Defective water pump

Ice thickness probe out of adjustment

Ice thickness probe dirty

Bin switch defective

Premature harvest

Non-Manitowoc components

Improper refrigerant charge

Defective hot gas valve

TXV flooding (check insulation and bulb mounting)

Defective fan cycling control

Because there are many possible external problems,

do not limit your diagnosis to only the items listed in these charts.

5-4

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Manitowoc Ice QM45 Series Safety Limit #1, Safety Limit #2, Because there are many possible external problems, Section