Mitsubishi pury -p350 ... 7102 fault

[Cmsaircon]

Hey guys really could do with a helpful pointer ... I've got a condenser address =60 ... Bc box 61 ... Indoor units 10 -21

I've tried running it up but 7102 fault at condenser , indoor controller say 96% please wait !!

I've checked my 30v at Tm 3 terminals .. At condenser & bc there fine , bc led goes off when I kill power to to condenser so defo not crossed cable from other system ( this is up & running now anyway )

Any ideas ? ?

Mitsubishi are suggesting pulling in a 1.5 mm cable to bc instead of 1mm .... A very long painful task ..

Puny help would be great
Thanks

[marc5180]

Hey guys really could do with a helpful pointer ... I've got a condenser address =60 ... Bc box 61 ... Indoor units 10 -21

I've tried running it up but 7102 fault at condenser , indoor controller say 96% please wait !!

I've checked my 30v at Tm 3 terminals .. At condenser & bc there fine , bc led goes off when I kill power to to condenser so defo not crossed cable from other system ( this is up & running now anyway )

Any ideas ? ?

Mitsubishi are suggesting pulling in a 1.5 mm cable to bc instead of 1mm .... A very long painful task ..

Puny help would be great
Thanks

What's the diversity on the system? Is there any chance it's over capacity.
Using SW10 on the outdoor board can you check what indoor units and BC box the outdoor system can see.

Firstly try a virgin restart and then disconnect TB3 from the outdoor unit and wait for the lights to go out. Check that the light is on the M-net board and you are getting the 30v dc.

[Cmsaircon]

Hiya ... Its within its capacity ive checked that , Did the sw 10 .. It shows up nothing !! It's basically not seeing anything in side the building !!
Think that's why mitsi saying change cable ? But it's same cable I've used many times its doubtful its that .

If it can't see the bc box would it still be able to see indoors through doing sw 10 ?
Everything to me seems to point to bc box problem !!

Is there a dip switch for virgin restart ? Or is this just the power down sequence ?

[marc5180]

I doubt it's the size of the cable but stranger things have happened. Are you actually getting 30vdc at the BC box and not less? So no voltage drop?

If not then Power off all indoor units, BC box and outdoor then carry out Virgin restart by flicking SW2-2 to on until the lights on the outdoor display monitor show a line (usually takes a minute or so).
Then power up indoors, BC box and then the outdoor.

Confirm 240v power is at the BC box though and the low voltage transformer is supplying 20-24v to the circuit board.

Lastly do you not have m-net voltage at any of the indoors? Or controllers?

[mick mernagh]

is this a new install

[Cmsaircon]

Defo getting 30vdc at the bc box & the first indoor unit ... Didn't check the rest but I'm guessing the problem is upto the first unit !!

Virgin restart .. Do I sw2-2 when everything is powered down and off ? Then power back up once the line comes on ?

Will check the circuit board on bc first thing am .

[Cmsaircon]

Yes new install 2 systems installed 1 working fine other this problem

[mick mernagh]

had this before on a couple of jobs where the wrong bc installed check bc model on piping diagram compaired to whats installed took me ages to find this the first time the outdooor cannot see any indoors same prob as you 7102

[marc5180]

Yes power everything down, turn on sw2-2 then power up the outdoor only, until the light shows a single line. Then power down the outdoor, put the dip switches back to what they were and turn everything back on in sequence.

Is it not possible to swap the BC box board with the other system that is working?

[Cmsaircon]

Unfortunately It's a different size bc box 10 port & the one I've got a problem is 13 port ... I have give mitsubishi model numbers they say they match up .. I did start to worry about wrong bc as its job handover Friday :0( !! ... Looks like I've got another day head scratching !!!

[Cmsaircon]

I think I've found cause of my problem , someone ��������has wired the flex from the spur wrong .. Live in to neutral & neutral into live!! ... I've changed it back to correct way and checked I'm getting 240v into box box ... Also checked I'm getting 240v into transformer & 30v out . Also checked the bc box fuse .. This is fine too !!

I'm still getting this fault ...is everything pointing to new board ? If so how do I know which board to order & change ? rely board or control board ??

Thanks

[marc5180]

Looking at the wiring diagram, I don't think that by wiring the fuse spare the wrong way it would cause a problem....well apart from it not working.

Did you disconnect TB3 (indoor units) from the outdoor unit and wait for the flags to go out? Did the 7102 fault go?

If so then You need to just connect a few units rather than all 10and see if the 7102 disappears, if not then I would agree that it is most probably the m-net board or the BC box board

Are the controllers still saying 96% loading?

[install monkey]

drop a new cable in temporary off the roof in the window to prove that no rodents or builders crap has nicked the m net cable- its a quick test that will save you on a new board in the bc box

[Cmsaircon]

Cheers guys ... All sorted !! ... I pulled a new cable from bc to 1st unit and then running up the system adding 1 unit at a time , I found the problem between units 11-12 ... Comms cable and control cable were crossed . I did also come across a few other poor cabling issues .

All sorted now , shame it wasn't done right first time

Thanks as ever for ya help

[marc5180]

Cheers guys ... All sorted !! ... I pulled a new cable from bc to 1st unit and then running up the system adding 1 unit at a time , I found the problem between units 11-12 ... Comms cable and control cable were crossed . I did also come across a few other poor cabling issues .

All sorted now , shame it wasn't done right first time



Thanks as ever for ya help

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