Power Transistor Check - Daikin E Series Service Manual

SiBE04-624
Caution
1) Hold the "CLOCK" button for 5 seconds.
2) Display "
3) "
4) Press the "CLEAN / FRESH" button for inverter test mode.
3.9

Power Transistor Check

Check No.15
(–) terminal of a tester
(+) terminal of a tester
Resistance in OK
Resistance in NG
Service Diagnosis
When the output frequency is low, the LED flashes slowly. As the frequency increases, the
LED flashes quickly. (It looks like the LED is lit)
If the operation is carried out with no load (the condition of the compressor is disconnected),
some of units may stop operation with "CT system error" (due to no electric current) or
"startup failure" (because the compressor does not turn). In this case, check if the LED is
flashing during "operation" to "malfunction stop". (Refer to the service manual of each air
conditioner for checking whether the alarm LEDs for CT system, startup failure, etc. are
provided or not.)
On completion of diagnose by this checker, be sure to re-crimp the faston terminal for
resetting the system.
(Otherwise, the terminal may be burned due to loosening.)
How to activate the inverter test mode
(The matrix display will appear on the remote controller.)
" on the matrix display of the remote controller and press the "CLOCK"
button.
T
" will be displayed.
Do not touch the live parts within 10 min. after the breaker is turned off.
Even after that, when you touch the parts, check to see that supply voltage of the power
transistor is less than 50 V with a tester.
Measure resistance at connector terminal on PCB or at the relay connector.
Power transistor
Direction of crimp
Faston terminal
UVW
(+)
Power transistor
UVW
(+)
several kΩ~several MΩ
This size is shortened
by "crimp".
Power transistor
(–)
Power transistor
UVW
∞
0 or
Check
(R5161)
UVW
(–)
207