Inverter Checker" Check - Daikin 3MKS50E3V1B Service Manual

SiBE121135
8.9

"Inverter Checker" Check

Check No.15
If 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 the compressor and check the output of the inverter.)
Step 1
Step 2
Step 3
Activate the power transistor test operation from the outdoor unit.
Service Diagnosis
Characteristics
Operation Method
Be sure to turn the power off.
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.
(1) Remove the terminals from
the compressor.
Compressor
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.)
1) Press the forced operation [ON/OFF] switch for 5 seconds.
(Refer to page 405 for the position.)
→ Power transistor test operation starts.
(2) Connect the terminals to the
terminals of the inverter
checker.
Be careful not to let the terminals (U,V,W)
touch each other. Otherwise, high voltage
is applied.
Check
Inverter checker
(R13940)
331