Thermo King 914 724, Manual

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Electric Standby Mechanical Diagnosis (Rev. 1/99)
82
Motor contactor burnout Low line voltage Increase voltage (must be ± 10% of
compressor motor rating)
Excessive line voltage Reduce voltage (must be ± 10% of
compressor motor rating)
Unit operates long or
continuously Shortage of refrigerant Repair leak and recharge
Discharge valve leaking Replace compressor
Thermostat faulty Replace cab box
Dirty condenser Clean condenser
Air in system Purge
Compressor inefficient Replace compressor
Plugged expansion valve Clean or replace
Iced or plugged coil Defrost or clean
Defective truck body insulation Correct or replace
Too many door openings Keep doors closed
Load too warm Precool hot product
Excessive superheat at expansion
valve
Adjust
Door seals worn Repair/replace
Box temperature too high Refrigerant shortage Repair leak and recharge
Thermostat set too high Reset control
Expansion valve or strainer plugged Clean or replace
Restricted lines Clean restriction. Tubing pinched
shut
Hot load Precool hot product
Expansion valve superheat too high
or too low
Adjust
CONDITION POSSIBLE CAUSE REMEDY