fujitsu fault codes

[Andy AC]

Hello guys, could any of you tell me what fault code E,01 is on a fujitsu cassette. Mod number AUY30RLB-W On R22. Machine spins indoor fan and very little else, all connections and wiring ok, fuses on indoor and outdoor boards ok.

Andy

[nike123]

Communication error indoor-outdoor. Check wiring and check voltage between terminal 1 and 2(N) with analogue multimeter for voltage swings.

[Andy AC]

Unfortunately, no longer have an analogue meter but the volatge measured with me digital one was anywhere between 50-70 volts.

[paul_h]

It should be about 70-100v as each unit puts out 20-60V out of phase to the other.

Cut power, disconnect one of the comms cables at either indoor or outdoor terminal. Switch power back on and see which one is good and reading 20-60V and which one is not putting out 20-60V.

edit: It's best to repeat this at both the indoor and the outdoor units to rule out a problem with the interconnecting cable itself.

[nike123]

You only disconnect wire from indoor-to-outdoor connection cable at terminal 1 at one connector (either indoor unit or outdoor unit) and measure voltage at terminal (1 and 2) at both indoor and outdoor connectors with that wire disconnected.
One that doesn't produce that voltage swings has faulty PCB.
Best is to measure voltage shortly after unit power up!

[paul_h]

You only disconnect wire from indoor-to-outdoor connection cable at terminal 1 at one connector (either indoor unit or outdoor unit) and measure voltage at terminal (1 and 2) at both indoor and outdoor connectors with that wire disconnected.
One that doesn't produce that voltage swings has faulty PCB.
Best is to measure voltage shortly after unit power up!

Lets say you are at the outdoor unit and have disconnected the comms line there and test.
If you find the outdoor unit being low volatge or not fluctuating, but the interconnecting cable showing 20-50V, it's fair to condemn the outdoor PCB as there's no cabling between you and the outdoor.
But if the outdoor was 20-50V but the cable from the indoor was 0V, would you just condemn the indoor PCB?

My point was, in that case, repeat the check at the indoor unit, as it could be a bad interconnecting cable that is the cause of reading 0V at the outdoor from the indoor unit line. The indoor unit could be fine.

So in some cases, you only need to do one check, that's the test that has the unit you are testing at show faulty.
In other cases you need to test twice, that's when the cable is testing dead and you have to remove the interconnecting cable as a possible source of fault.

Edit: Here , it's terminal 3 that is the comms line, not terminal 1, terminal 1 is active here.
I don't know what it is in the UK, but check before you disconnect in case terminal 1 is the active.

[nike123]

That is why I wrote first to test interconnecting cable and than voltage. But your way is equally good, and I did not read it thoroughly at first, and since English is not my native, some details are not seen that time.

Sorry, it was not my intention to dispute your answer, it is only intended to clarify some small things since I thought (at that time) that is not clear.

[paul_h]

No problems, easier just to double check the comms when diagnosing rather than using some other way of testing the cable.

Yes, your units seem different if terminal 1 is the comms line. Something for both of us to bear in mind when telling people from other countries what terminals to check! Same actual terminal we are testing, but your's are numbered right to left, but ours are numbered left to right.

[nike123]

No problems, easier just to double check the comms when diagnosing rather than using some other way of testing the cable.

Yes, your units seem different if terminal 1 is the comms line. Something for both of us to bear in mind when telling people from other countries what terminals to check! Same actual terminal we are testing, but your's are numbered right to left, but ours are numbered left to right.

Not always, sometimes!