General AOH18LMAK2

[aircon50]

Hi guys - thinking caps on please!
I hasten to add that this not my job - I was asked to look at it for an opinion.
System consists of above exterior unit, a ASHA09LACM and ASHA12LACM. The exterior unit PCB has been replaced, as have both EEV's (don't know why?)
From power on the EEV checks can be heard. Switch either interior units on - nothing happens apart from interior fan. There are NO error codes on either interior unit nor on exterior PCB. The situation is the same whether in cool or heat mode.
Disconnect any thermistors from the PCB and the relevant error code is generated on the LED. However, if the pressure switch, compressor thermal switch or EEV's are disconnected there is no error code.
Voltages at terminal strip for power in, and out to interiors are ok, at approx 230vac. There is, from memory, approx 300vac at L1 and L2 on ACTPM for the choke. And again, approx 300vdc at TM104 and TM105 on PCB and corresponding 300VDC at P and N1 on ACTPM.
Questions
What should be seen at communication terminal? I am unsure if it an AC or DC voltage, and if so where is measured across? Or is it something like a modulated frequency that would an oscilloscope?
And is the communication generated by interior, or exterior unit?
Sorry - I don't get to check inverters very often.
Any information would be greatly appreciated.
Thanks, Graham

[aircon50]

Hi all.
I'm astounded that after more than 170 views nobody has replied.
I was hoping that Tayters, Nike123, Install Monkey etc would have been straight back! Aah well.....
(BTW - no offence is meant by my opening sentence)
Graham

[r.bartlett]

emails sent.

[Tayters]

Hi all.
I'm astounded that after more than 170 views nobody has replied.
I was hoping that Tayters, Nike123, Install Monkey etc would have been straight back! Aah well.....
(BTW - no offence is meant by my opening sentence)
Graham

Been helping the kids at the local orphanage so missed the post. Not that I've got a clear cut answer anyway!

Measure comms on AC between N and 3, should go up to around 100V AC. If it's around 50V AC then normally this means only one side is communicating only. Not sure about your particular model but I've seen some not actually work this way and it seems the outdoor comms only livens up when it gets the right signal from indoors. See how you go with that one.
There is an LED on the outdoor PCB, does this light up with a fault? 1 flash for comms error, 8 flashes for pressure switch.
Is this the right outdoor unit, not another one hidden away somewhere?
Is a comms error generated one both indoor and outdoor when comms wire removed?

Cheers,
Andy.

[install monkey]

change the condenser fans!

[install monkey]

http://www.mediafire.com/view/6696s1...ng%20Guide.pdf
tayters inverter test guide!

[aircon50]

Thanks Tayters and Install Monkey. I think I am getting closer.... The 1200uF capacitor! Cap check indicates nothing and is open circuit. Waiting for replacement. (169€ + shipping + import taxes from Eurofred Spain!) Will let you know as and when....
Graham