Fujitsu FO2416RTJNAA - Page 42

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Diagnostics
9.0 DIAGNOSTICS & TROUBLESHOOTING
9.9 Service Analyzer Charts
COMPRESSOR OVERHEATING
SYMPTOM POSSIBLE CAUSE CHECK/REMEDY
High superheat
(greater than 15°F
[8.3°C] at coil)
Low charge Check system charge.
Faulty metering device Restricted cap tube, TXV
Power element superheat out of adjustment internally
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High internal load Hot air (attic) entering return
Heat source on; miswired or faulty control
Restriction in liquid line Drier plugged.
Line kinked.
Low head pressure Low charge
Operating in low ambient temperatures
Vapor or liquid line subjected to high heat source Hot attic
Hot water line
Low line voltage Loose wire connections Check wiring.
Power company problem, transformer Report problem.
Undersized wire feeding unit Correct and complete diagnosis.
High line voltage Power company problem Report problem.
High head
pressure
Overcharge Check system charge.
Dirty heat pump coil Clean coil.
Faulty or wrong size heat pump fan motor Check capacitor. Replace fan motor.
Faulty fan blade or wrong rotation Replace fan blade.
Replace with correct rotation motor.
Recirculation of air Correct installation.
Additional heat source Check for dryer vent near unit.
Check for recirculation from other equipment.
Noncondensibles Recover refrigerant. Evacuate and recharge system.
Equipment not matched Correct mismatch.
Short cycling of com-
pressor
Cycling or faulty pressure control Check pressures and address cause of high or low pres-
sure. Replace pressure control if faulty.
Loose wiring Check unit wiring.
Thermostat Located in supply air stream
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Customer misuse
TXV restricted Internal foreign matter
Power element failure
TXV too small
Equilizer tube plugged
Distributor tube restricted Restricted with foreign matter
Kinked
Inside diameter reduced from previous compressor
failure