Results 1 to 9 of 9
  1. #1
    Join Date
    Nov 2014
    Location
    Great Britain
    Posts
    6
    Rep Power
    0

    Airforce Air Conditioner - Error E6



    Hello All,
    I have a split air conditioner which has just decided to stop working. It had worked the day before. The unit was marketed as Airforce, model number GWHD12B2NK3AB as sold by B&Q several years ago.
    The outdoor unit circuit board is a GREE, board number GRJW9M-A1 V2.31.
    What I am interested in knowing is the method of data communication between indoor and outdoor unit. Is it a pulsed voltage or a standard protocol? The signal is received by a set of opto-isolators on the outside board and then sent to the microprocessor on that board. I would guess that information from the outside unit is sent to the indoor unit in an identical manner.
    Any advice on the communication protocol would be gratefully received.
    Regards



  2. #2
    Join Date
    Oct 2007
    Location
    manchester
    Age
    50
    Posts
    5,707
    Rep Power
    45

    Re: Airforce Air Conditioner - Error E6

    e6 - When outdoor unit is energized and fails to receive data of indoor unit within 30 seconds, an indoor unit communication fault is
    reported. The compressor and the outdoor unit will be shut off,
    and the four way valve will be stopped 2 minutes after the
    compressor outage in heating state.
    If indoor unit fails to receive information of outdoor unit, a
    communication fault is reported. The indoor unit is shut off and
    an indicator is twinkling. If the display board fails to receive
    information of outdoor unit, a communication fault is determined
    and displayed and the machine does not actuate. After
    communication becomes normal, the system can restore to the
    previous running state itself.

  3. #3
    Join Date
    Oct 2007
    Location
    manchester
    Age
    50
    Posts
    5,707
    Rep Power
    45

    Re: Airforce Air Conditioner - Error E6


  4. #4
    Join Date
    Nov 2014
    Location
    Great Britain
    Posts
    6
    Rep Power
    0

    Re: Airforce Air Conditioner - Error E6

    Hello Install-Monkey,
    Many thanks for your kind replies. I have taken a look at the pdf and I believe that the communication is as described in it. It's the protocol I am interested in such as whether it's RS232, RS458, Modbus or such like so that I can check that both the indoor and outdoor units are attempting to communication with each other. I know that the data communication is between the COM and Neutral line and I have the equipment to monitor the line safely to check.
    Kind regards
    Paul

  5. #5
    Join Date
    Apr 2008
    Location
    Southampton, England
    Age
    49
    Posts
    1,045
    Rep Power
    35

    Re: Airforce Air Conditioner - Error E6

    Hi Paul,
    Normally with splits the 240 AC signal is used as a king of carrier signal. The outdoor will pulse the positive half to build up a binary signal and the indoor looks at this half whilst using the negative half for it's time to communicate which is what the outdoor is looking for. Might have got those the wrong way round but that's the concept anyhow.

    It doesn't matter if the pulse is on a lower or high part of the sine wave as the opposite unit is just looking for a + or - set of pulses. The actual language which is used seems to be a closely guarded secret which only the designers seem privy to. Don't think it will be any standard lingo. Manufacturers bring out a new system and it's incompatible with the old gear so I guess that tells the you the protocol would be different. You can hook up an oscilloscope to see what it looks like. Otherwise disconnect the comms wire, power up and see if you get a DC voltage from each unit. One will be +, the other - varying from 0 to 80 odd volts. After a while you will get a comms error then comms is stopped hence powering up to initiate comms to begin with.

    Some makes do it in a different way. MHI and I think Mitsi Electric units for example have a 20V comms signal so not sure what's going on there...
    If you have an EEV outside then a good idea is to see if the valve initialises on power up which tells you the outdoor unit powers up enough to set itself up therefore comms from this unit probably alright. Yours might not have an EEV but I think it's an inverter so there may be a few voltage measurements around the PCB you could take, 5V DC across an unplugged probe is a good start. Comms wiring, neutral wiring, high level pump switches if fitted are other bits to have a looks at.

    Cheers and Beep Beep. :-)
    Andy.

    Edit: Found wiring diagram: http://www.lomax.dk/brochurer/Brugsvejledning.pdf
    Last edited by Tayters; 24-11-2014 at 12:54 AM. Reason: How do you roll a joint to look like a knob? Use four skins. I'll get my coat...
    Health and safety first..........unless I'm in a hurry.

  6. #6
    Join Date
    Oct 2007
    Location
    manchester
    Age
    50
    Posts
    5,707
    Rep Power
    45

    Re: Airforce Air Conditioner - Error E6

    mhi have outdoor eev's 2 of em- with the hard wired controller you can see the valve position

  7. #7
    Join Date
    Nov 2014
    Location
    Great Britain
    Posts
    6
    Rep Power
    0

    Re: Airforce Air Conditioner - Error E6

    Quote Originally Posted by Tayters View Post
    Hi Paul,
    Normally with splits the 240 AC signal is used as a king of carrier signal. The outdoor will pulse the positive half to build up a binary signal and the indoor looks at this half whilst using the negative half for it's time to communicate which is what the outdoor is looking for.
    Hello Tayters
    Many thanks for your comprehensive reply and safety warning. I have many years experience in electronic servicing so I will be taking safety extremely seriously. My interest in only in checking to see if it is a comms fault due to electronic component failure which will be serviceable. Should the fault be elsewhere then I guess I will be replacing the system.
    Your response is gratefully received.
    Kind regards
    Paul

  8. #8
    Join Date
    Nov 2014
    Location
    Great Britain
    Posts
    6
    Rep Power
    0

    Re: Airforce Air Conditioner - Error E6

    Hello,
    Please could anyone advise me what the opto-isolator part numbers are for IC01 & IC02 on the outside board. I can only partially read the part number (PC8??) but cannot make out the full numbers since they are very feint.
    Many thanks
    Paul
    Outside board.jpg

  9. #9
    Join Date
    Nov 2014
    Location
    Great Britain
    Posts
    6
    Rep Power
    0

    Re: Airforce Air Conditioner - Error E6

    Hi,
    I may have traced the fault to a metal oxide resistor “R4” on the internal circuit board whose colour banding does not appear to match the measured value. It looks like a 210 ohm but measures 22K.
    Could anyone tell me what the value should be or can tell me the colour bands.

    R4 is the large resistor below D5

    Airforce GWHD12B2NK3AB
    Rated power 1600/1650watts
    Cooling capacity 3500w
    Heating capacity 3900w
    Refrigerant R 410A
    Internal circuit board GRJ9Q-A V1.1

    Regards
    Paul

    pIC2.jpg
    Last edited by Road_Runner; 06-12-2014 at 09:05 PM.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •