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STRATUS TA20 Series Industrial Air Conditioners User Manual
1st Edition RevA.
TROUBLESHOOTING GUIDE
COMPLAINT
SYMPTOM
PROBABLE CAUSE
ACTION
Unit will not run
Controller not on
Evaporator fan not on
No power
Check circuit breaker. Check voltage at power source. Power must match unit
requirements, 15 Amps min.
Unit power switch off
Check rocker switch inside panel.
Compressor
stalls on startup
Compressor hums for 3 -5 seconds
then trips
Insufficient power under load
Check power source, wiring and circuit breaker capacity using power quality
meter.
CB on overload
Defective or disconnected run capacitor
Have qualified A/C tech test and replace.
Faulty compressor
Have qualified A/C tech test winding impedance.
Replace compressor if defective.
Controller on
LED/Snowflake not on
Check programmed setpoint and indicated temperature.
LED/Snowflake blinking
Unit off on anti-short cycle time delay - clears after 5 minutes.
Evaporator fan not running
Defective evaporator motor
Have qualified A/C tech clean, repair or replace.
Evaporator running
CA alarm displayed
Setpoint too low
Adjust temperature setpoint.
Low ambient
Warm unit/Install low ambient crankcase heater.
Evaporator coil frozen
Thaw and clean coil. Check for clogged drain. If enclosure obstruction causing
air re-circulation, remove obstruction.
Low refrigerant
Have qualified A/C tech check.
Unit runs but
does not cool
properly
Compressor cycling
Cycling on set point
Reprogram setpoint or increase Hy.
HA2 alarm intermittent
Dirty condenser
Clean condenser coil.
Condenser air flow blocked
Installation must meet minimum clearance for condenser air flow.
Adjacent unit heating air
Install baffle/deflector or move unit(s).
Perform touch test:
Compressor hot (190°F)
Suction accumulator cold ( 50 to 65°F)
Good condenser
Have qualified A/C tech check evaporator section.
Restricted air flow
Clean evaporator.
Recirculating air flow
Remove restriction/Install baffle/Install fan.
Unit vibrating or
noisy
Noise
Possible freight damage
Inspect all points of mechanical contact between tubing and shroud or chassis.
Tube rattling against shroud
Compressor rattling against shroud
Inspect compressor mounting.
Foreign object in fan/blower
Clean blowers; tie-wrap any loose wiring. Replace air filter to prevent
recurrence.
Broken or bent fan blade
Replace blower unit or fan blade.
High refrigerant pressure due to dirty air filter,
blocked or recirculating condenser air flow or
dirty condenser
Test air temperature entering and leaving condenser. Entering should equal
ambient. Leaving should equal en 15 degrees. Clean condenser with
degreaser and low pressure rinse. Clean or replace filter.
Condensate
draining from
overflow
Drains during normal operation
Door partially open or air leaks between unit
and enclosure
Check door gasket and gasket compression on closing.
System must be closed loop.
Condensate
draining inside
unit
Water leaking out around compressor
Blockage in evaporator drain lines prevents
water getting to the boil-off pan.
Clean condensate drains with degreaser. Check for crushed or blocked drain
lines. Clean evaporator coil and check for source of contamination.
Iced-up evaporator coil
Defective evaporator blower
Have qualified A/C tech clean, repair or replace.
Low refrigerant
Have qualified A/C tech check level.
Troubleshooting Guide
