Mitsubishi City Multi

[El Padre]

Greetings to all,
I am hoping for some advice regarding a system; PURY-P400YGM, the 5 fan coils are PEFY-P125VMM-E(DUCTED). I have visited the site but could only access the outdoor unit, the problem is that on one local controller PAR-27 the mode button flashes irrespective of what mode is selected, Mitsi technical suggested that this could be caused by an incorrect port address, as the system is a couple of years old what other faults could cause the same symptoms? I shall return to site soon when I can gain access to the entire system, I will not have the benefit of Mitsitechnical however because this will be out of office hours. I shall also fit remote return air sensors on all the systems on this site as the remote controller sensors that are currently being used are not ideally located, does a setting exist like the daikin factory setting where the system can use both unit and controller sensors? Finally I have a spare PAR-27 controller and was considering connecting it to the outdoor unit to test each fan coil, as I have never attempted to register/unregister a controller like this, how complicated is it?

Lets hope that this weather continues!
Thanks in Advance

[stuartwking]

the remote sensors are pretty straight forward. make sure you plug the into the right plug and change a switch on the indoor unit and i THINK thats it.
I am not sure about hooking a PAR to the outdoor, never heard of that before.

[Thermatech]

Normally if 2 indoor units are addressed for the same BC port then they both need to be in the same mode as the port can only provide one of heat or cool to the 2 units.
I both units have a remote controller then both units will only work if both set to the same mode.
So incorrect branch address setting is prime suspect
but
as the indoor units are size 125 it should have been stopping on a 7107 fault as the system should see more than the max size 140 addressed for one port.
In this case you would have total 250 addressed to the same port.

So suspect something else at play in this instance.


Connect PAR 27 at outdoor & assume control of any indoor unit you want
Just follow the service manual.
Make sure you set the address of the remote controller for an address not used by any other RC otherwise you will get 6600 duplicate address fault & make sure you delete its connection to any units before you disconnect otherwise you will leave a ghost RC in the Mnet system which will make communication faults as the system will be looking for a RC which is no longer connected.

For the remote sensor option there is no average between RC & remoet sensor available.
1/ make sure to plug remote sensor in the red plug on the indoor board which is for the unit mounted return air sensor.
2/ If the return air sensor is at occpant level in the room then best remove the heating 4 deg C diff option with the SW 3-8
3/ Reset the SW1-1 for indoor unit temp sensor.
4/ 240v power reset & the unit will work to the new settings.

Good luck

[El Padre]

Thanks Thermatech,
I am not returning for a few weeks, but I shall let you know how I get on!