Mitsi city multi R407C fault..HELP

[garytreez]

Heres a weird one, can anyone help.
Multi city R407C PURY 250 that controls 12 indoor ceiling units each with own controller. Outdoor unit is ok i.e runs through 51 then rests at 1 when reset at isolator & led rests at constant red awaiting a communication. no start up at all.
all indoor units set at cool 19 degrees & 7 units are fan only because outdoor unit wont fire up & 5 units are doing nothing but show cool symbol on panel flashing (cooling not available). No error codes from any part of system at all.
All SW switches on outdoor PCB are off except SW3 no10 (as advised by mitsi tech). Have tried a test run but nothing. Mitsi tech has suggested that i activated SW2 No 2 to reconfigure the BC but this doesnt seem to work.
I have tried allsorts.....isolating indoors and outdoors to reset..but nothing.
The unit has fired up for a while a few weeks ago but keeps cutting out to this problem. a fellow a/c engr suggested that i get a mitsi tech to come to site to plug in laptop to reconfigure..........
ANY IDEAS PLEASE ! :confused::confused:

[AbsoluteWDJ]

Heres a weird one, can anyone help.
Multi city R407C PURY 250 that controls 12 indoor ceiling units each with own controller. Outdoor unit is ok i.e runs through 51 then rests at 1 when reset at isolator & led rests at constant red awaiting a communication. no start up at all.
all indoor units set at cool 19 degrees & 7 units are fan only because outdoor unit wont fire up & 5 units are doing nothing but show cool symbol on panel flashing (cooling not available). No error codes from any part of system at all.
All SW switches on outdoor PCB are off except SW3 no10 (as advised by mitsi tech). Have tried a test run but nothing. Mitsi tech has suggested that i activated SW2 No 2 to reconfigure the BC but this doesnt seem to work.
I have tried allsorts.....isolating indoors and outdoors to reset..but nothing.
The unit has fired up for a while a few weeks ago but keeps cutting out to this problem. a fellow a/c engr suggested that i get a mitsi tech to come to site to plug in laptop to reconfigure..........
ANY IDEAS PLEASE ! :confused::confused:

Is there any building or system central control. Might have Mode Operation disabled for local remotes.

[Thermatech]

A total system power reset can help sometimes.
Possible problem is indoor units not completing electronic hand shake with BC box.
Power off all indoor units, BC box & outdoor unit.
1/ power on to all indoor units.
2/ power on to the BC box. Confirm 240v power is at the BC circuit board & low voltage transformer is supplying 20 - 24v to the circuit board.
3/ power on to outdoor unit.

You can also do a virgin restart with SW2-2 but seems you already tried this.

You can also monitor all the indoor unit data from the outdoor unit using engineers mode SW1 setting & display.
From this you can check that the outdoor unit can see all the indoor unit Mnet address / branch address / capacity code / temperature sensor data / mode ect ect ect.

If the outdoor unit can see all the indoor units & you can switch each indoor unit on /off at the local remote controller then you have to suspect some problem with the BC box circuit board.

[garytreez]

Is there any building or system central control. Might have Mode Operation disabled for local remotes.


The system has an "evolve" bms system. the bms guy has deactivated it until i find the problem.

[garytreez]

A total system power reset can help sometimes.
Possible problem is indoor units not completing electronic hand shake with BC box.
Power off all indoor units, BC box & outdoor unit.
1/ power on to all indoor units.
2/ power on to the BC box. Confirm 240v power is at the BC circuit board & low voltage transformer is supplying 20 - 24v to the circuit board.
3/ power on to outdoor unit.

You can also do a virgin restart with SW2-2 but seems you already tried this.

You can also monitor all the indoor unit data from the outdoor unit using engineers mode SW1 setting & display.
From this you can check that the outdoor unit can see all the indoor unit Mnet address / branch address / capacity code / temperature sensor data / mode ect ect ect.

If the outdoor unit can see all the indoor units & you can switch each indoor unit on /off at the local remote controller then you have to suspect some problem with the BC box circuit board.

Thanks for the reply...ill give it a go :cool:

[garytreez]

UPDATE
was a blown pcb in the bc box......fixed !!