Mitsubishi 1102

[Northy303]

Model pefy p200 Vmm e
Checked thermistors all read ok and are in range
Reclaimed and weighed gas charge all ok
Changed lev head to indoor and controller board
Ran all day ok then 1102 fault turns up again every 24 hrs or so.
Apart from brazing in a new lev valve is there anything else I need to be looking at.
Many thanks in advance.
Matt

[Neddy]

Hi Matt,

have you the outdoor door model number? Which refrigerant is it on? How many indoor on the system?

[Northy303]

Hi neddy
Thanks for the reply went back today changed lev head and controller board.
Couple of hours later 1102 fault.
Went to the outdoor pury p200 vgma and it has 1 bc box with 7 indoor pefy ducted units and 5 controllers.
The 1102 fault always comes up on the same controller and has happened since the install of the system.
I reset the system and put all units on heating. High side pressure was 35 bar and suction was 10 bar (r410a) rang Mitsubishi and did dipswitch settings and came out with 29 bar on discharge.
Took temp of discharge at comp and was around 80 degrees c.
When I started running a few on cooling and heating the temperature went up to 100 degrees.
I have noticed that when that controller faults out sometimes it is the only unit running and Mitsubishi think that this could be a reason as it is only a 2 kw.
I am beginning to think that it is overcharged?
Any thoughts
Thanks in advance.

[marc5180]

Hi neddy
Thanks for the reply went back today changed lev head and controller board.
Couple of hours later 1102 fault.
Went to the outdoor pury p200 vgma and it has 1 bc box with 7 indoor pefy ducted units and 5 controllers.
The 1102 fault always comes up on the same controller and has happened since the install of the system.
I reset the system and put all units on heating. High side pressure was 35 bar and suction was 10 bar (r410a) rang Mitsubishi and did dipswitch settings and came out with 29 bar on discharge.
Took temp of discharge at comp and was around 80 degrees c.
When I started running a few on cooling and heating the temperature went up to 100 degrees.
I have noticed that when that controller faults out sometimes it is the only unit running and Mitsubishi think that this could be a reason as it is only a 2 kw.
I am beginning to think that it is overcharged?
Any thoughts
Thanks in advance.

You had a high side pressure of 35 bar but the systems was seeing 29bar?

If that's the case it's your high pressure transducer that's at fault.

[Neddy]

Argee with Marc. Check the high pressure transducer. Switch the system off. Let the pressure equalise. Connect gauges and compare the reading on your gauges against the reading via the dip switches.

[Keza]

Agree with Marc and neddy,

But also have to check system whilst running, to check that the voltage output of the transducer rises with the rise in pressure.
Had one recently that tested fine at standing pressure but when the unit ramped up it didn't increase its voltage output with the rise in pressure and thus keeping the fans off high speed.

Good luck, Kez