Norlake ZR152 Serie Manuel D'instructions page 4

MALFUNCTION
Compressor will not start - no hum
Compressor starts and runs, but short cycles on overload
protector
Compressor will not start - hums but trips on overload
protector
Compressor operates long or continuously
Compressor runs fine, but short cycles
Starting capacitor open, shorted or blown
Relay defective or burned out
Refrigerated space too warm
Standard temperature system freezes the product
Objectionable noise
REFRIGERATION SYSTEMS - ALL MODELS
POSSIBLE CAUSE
1. Unplugged or power off
2. Fuse blown or removed
3. Overload tripped
4. Control stuck open
5. Wiring incorrect
1. Improperly wired
2. Low voltage to unit
3. Starting capacitor defective
4. Relay failing to close
1. Low voltage to unit
2. Overload defective
3. Excessive head pressure
4. Compressor hot -- warm ambient
1. Short of refrigerant
2. Control contact stuck
3. Evaporator coil iced
4. Restriction in refrigeration system
5. Dirty condenser
1. Overload protector
2. Cold control
3. Overcharge
4. Air in system
5. Undercharge
1. Relay contacts stuck
2. Low voltage to unit
3. Improper relay
1. Incorrect relay
2. Voltage too high or too low
1. Control setting too high
2. Refrigerant overcharge
3. Dirty condenser
4. Evaporator coil iced
5. Not operating
6. Air flow to condenser or
7. Warm ambient conditions
1. Control setting is too low
2. Control points stuck
1. Fan blade hitting fan shroud
2. Tubing rattle
3. Vibrating fan blade
4. Condenser fan motor rattles
5. General vibration
6. Worn fan motor bearings
4
SOLUTION
1. Plug in service cord or turn on power
2. Replace fuse
3. Determine reasons and correct
4. Repair or replace
5. Check wiring against the diagram
1. Check wiring against the diagram
2. Determine reason and correct
3. Determine reason and replace
4. Determine reason, correct or replace
1. Determine reason and correct
2. Check current, replace overload protector
3. Check ventilation or restriction in
refrigeration system
4. Check refrigerant charge, fix leak if
conditions necessary
1. Fix leak, add charge
2. Repair or replace
3. Determine cause, defrost manually
4. Determine location and remove restriction
5. Clean condenser
1. Check wiring diagram
2. Differential too close – widen
3. Reduce charge
4. Purge and recharge
5. Fix leak, add refrigerant
1. Clean contacts or replace relay
2. Determine reason and correct
3. Replace
1. Check and replace
2. Determine reason and correct
1. Reset control
2. Purge refrigerant
3. Clean condenser
4. Determine reason and defrost
5. Determine reason, replace if necessary
6. Remove obstruction for free air flow – no
evaporator blocked storage on top of walk-in
7. Ambient conditions should be 90° or less
1. Reset the control
2. Replace the control
1. Reform or cut away small section of
shroud
2. Locate and reform
3. Replace fan blade
4. Check motor bracket mounting, tighten
5. Compressor suspension bolts not
loosened on applicable models - loosen
them
6. Replace fan motor
02/15 150139 Rev. E