Fujitsu FO20R Series Installation Instructions Manual page 67

9.12 Service Analyzer Charts (cont.)
Short cycling of Low charge
compressor (cont.)
Faulty internal overload
Voltage present on Communication failure from VSODC to inverter.
load side of inverter
and compressor
won't run
Compressor windings
187 – 252VAC Thermostat
present at input to
Compressor control circuit
inverter
No voltage at input Blown fuses or tripped circuit breaker
to inverter
Improper wiring
Improper voltage High voltage
Low voltage
Liquid in the com - Faulty stator heat circuit (single leg output
pressor shell
to compressor)
Too much liquid in
Incorrect piping
system
Overcharge
9.0 DIAGNOSTICS & TROUBLESHOOTING
Check system charge.
Dirty coil
Duct too small or restricted
Replace compressor.
Check communication harness connectors and wire
continuity.
Check for correct ohms.
Check for control voltage to contactor coil.
High-pressure switch
Low-pressure cut-out
Ambient thermostat
Stater heat is active
Check for short in wiring or unit.
Recheck wiring diagram.
Wrong unit
Power supply problem
Wrong unit
Power supply problem
Wiring undersized
Loose connections
Check piping guidelines.
Check and adjust charge.
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