Service manual

SiBE041134 Check
Service Diagnosis 105
5.7 “Inverter Checker” Check
Check No.15  Characteristics
If an abnormal stop occurs due to compressor startup failure or overcurrent output when using
an inverter unit, it is difficult to judge whether the stop is caused by the compressor failure or
some other failure (control PCB, power module, etc.). The inverter checker makes it possible to
judge the cause of trouble easily and securely. (Connect this checker as a quasi-compressor
instead of compressor and check the output of the inverter)
 Operation Method
Step 1
Be sure to turn the power off.
Step 2
Install the inverter checker instead of a compressor.
Note:
Make sure the charged voltage of the built-in smoothing electrolytic capacitor drops to 10
VDC or below before carrying out the service work.
Reference:
If the terminals of the compressor are not FASTON terminals (difficult to remove the wire on
the terminals), it is possible to connect wires available on site to the outdoor unit from output
side of PCB. (Do not connect them to the compressor at the same time, otherwise it may
result in incorrect detection.)
Step 3
Activate the power transistor test operation from the outdoor unit.
1) Press the forced cooling operation [ON/OFF] button for 5 seconds.
(Refer to page 165 for the position.)
→ Power transistor test operation starts.
(R14926)
(1) Remove the terminals from
the compressor.
(2) Connect the terminals to the
terminals of the inverter
checker.
Compressor
Inverter checker
Be careful not to let the terminals (U,V,W)
touch each other. Otherwise, high voltage
is applied.