Mitsibishi VRV System 8 out of 10 units work

[moondawn]

Hi There

Can Anyone suggest why the last two units on the system will not run.

Outdoor is a p250 R410a and has 10 ic. one bc and a g50.
g50 is set up for floors 2 and 1 not 0 which i am working on.

8 of the indoor units work fine but units addressed 37 and 38 will not work they contiually ho. the mitsibishi maintenace tool which we plug on to the remote controller shows 37 and 38 and its port nos. so looks like the m-net is picking it up.

I have self addressed the two remotes so it stops ho-ing but when you switch the remote on it does nothing and then switches the remote off.

the maintenance tool shows i have not duplicated any addresses. i ahve changed the remote controller for one that works have swapped one of the main pcbs with one that works. have pulled in a new transmission cable from the last working unit to the one that dont work.

also changed remote cable, checked the index is not over capacity, checked dip switches are right and checked power gettin 240 going on to the board, indoor fan. any clues ???????????

[eggs]

don't know how this works but it did for me.
change the addresses on the two dead units to two totally unconected illogical numbers, eg 49 and 66,
any two addresses that are not being used.

this worked for me.

dont know why, don't know how, but it did.

cheers

eggs

[moondawn]

cheers for the reply eggs.

Will give it a try tommorow so they should be to follow in line 37 and 38. will put them as 40 and 41 and see if it works. will let you know how i get on

Cheers

[chilly]

I agree with changing numbers, I would also make sure the spark's have wired the comms correctly, I've had jobs where they have put loops into the comms chain, some time you dont get a problem, sometimes you do, and when you do its a strange one, as strange things just start happening, because the comms is looping.

So, make sure comms runs in dasy chain from first to last and does not fork or split at any point. Also make sure your not getting spiking, the comms should be screened, and the screen activated by earthing one end only. If both ends are earthed the whole thing becomes a big arial and that does cause strange problems.

Hopefully changing the adrees for diferent numbers will solve this though. Also i wouldnt let any unit self adress, number everything.

Hope that helps

[moondawn]

hi guys

my internet been down just back up, changed the addresses too 45 and 49 instead of 37 and 38 and it worked. strange but glad its working now

thanks for your help guys

[eggs]

yipee, i've helped someone

cheers

eggs