Input Overcurrent Detection - Daikin FTX-N Series Service Manual

Troubleshooting for Outdoor Unit
7.5

Input Overcurrent Detection

E8
Error Code
Method of Error
An input overcurrent is detected by checking the input current value with the compressor running.
Detection
Error Decision The current exceeds about 12.0 ~ 20.0 A (depending on the model) for 2.5 seconds with the
Conditions compressor running.
The upper limit of the current decreases when the outdoor temperature exceeds a certain level.
Supposed
 Outdoor temperature is out of operation range.
Causes  Defective compressor
 Defective power module
 Defective outdoor unit PCB
 Short circuit
Troubleshooting
Reference
Check No.15 Refer to P.186
Reference
Check No.17 Refer to P.190
159
Be sure to turn off the power switch before connecting or disconnecting
Caution
connectors, or parts may be damaged.
* An input overcurrent may result from wrong internal wiring. If the system is interrupted by an input
overcurrent after the wires have been disconnected and reconnected for part replacement, check the
wiring again.
Check No. 17
Check the installation condition.
Start operation and measure the
input current.
Input current
flowing above its stop level?
YES
Turn off the power and disconnect
the harnesses U, V, and W.
Check No.15
Check with the inverter analyzer.
Any LED off?
NO
Turn off the power, and reconnect
the harnesses. Turn on the power
again and start operation.
Check No. 18
Check the discharge pressure.
NO
* Inverter analyzer:
RSUK0917C
YES
SiUS091601EA
Replace the outdoor unit
PCB (main PCB).
Correct the power supply or
replace the outdoor unit
PCB (main PCB).
(R21863)
Part 6 Service Diagnosis