Daikin E5 Error and Weird Issue.

[R.J.]

Model - RXYMQ48PVJU

I found this unit with a grounded compressor and burned PCB. Replaced both and initiated a testrun followed by a shutdown on code E5. I checked the stopvalves, incoming power, and all connections including compressor wiring for correct orientation. I also checked to make sure the refrigerant was equalized.

Here's what happens:

I have an amp meter clamped on one of the lines. The unit will initiate compressor start and will drive to about 5 amps go up to about 18 amps, ramp back down to about 5 amps, and back up again. This all happens within 5-10 seconds. Unit will initiate a slight delay and start the process over again. Every time the compressor attempts to start, it will visibly shudder.


I don't have an inverter checker, however I used Mode 2 28 to test the phase balance. All measured about 9 V.A.C. (It seems kinda low but Daikin says okay).

I really can't believe a new compressor would be DOA, but I suppose it's possible.

Any ideas or other things to check?

[Brian_UK]

I assume the burnt PCB was the inverter pcb.

Have you checked all of the tests on the pcb as detailed in the service manual? https://bit.ly/2sIhR3x

[frank]

Did you make sure to reconnect the compressor terminals as you found them?
You may have phase connections incorrect

[R.J.]

Thought I should follow up with this.

I checked the Inverter board as per the manual. I believe the P + N wires are the same as the test points C+ & C- on the board?

Board all checked out. Replaced compressor and started right up. Probably very rare, but the new out of box compressor was bad.

I purchased an EDC inverter checker, but could only get three of the leds to light up on this particular unit. I then used it on a known good unit and none of the leds lit up at all. Since it's 3 phase AC coming out, I assume the test leads shouldn't matter in how they are connected. The only thing I can think of is when the system is put into transistor test mode or started on a regular cooling cycle, the voltage is too low to fire off the leds. I know the tester has internal resistors in the circuit. Disappointed this tool didn't work for me.

[narkom]

3 phase AC coming out you can check with the True RMS multi meter.

[Brian_UK]

Thanks for the update RJ.