Mitsubishi Electric citi multi Code 5107+5115

[The captain]

Helo guys, working on a mitsubishi electric citi multi VRF on r407c PURY-P250YMF-C. I have the code 5107 which turned out to be a thermistor Th7 fault. The thermistor was found shorted showing 46 ohms insted of 6.3K ohms and was replaced. Now the system starts, but after about 2 mins cuts out on 5115 ? I removed the thermistors from their pockets and reset unit but still cuting out on 5115? any ideas would be great.

Ps, picked up new thermistors from mitsubishi but no pin connector was included so i removed old pin connector and connected the new one in with lead soilder and covered join with heat shrink. :confused:

[superswill]

5115 is sensor fault TH15 in a BC box

(TH15 Resistance 6.4Kohms 20 deg C)

[The captain]

Hi Paul, Thanks for the Info. Could you please tell me more about the BC box? I have very little knowlage on VRF inverter systems. Is it the box in ceiling space with the FCU's piped to it? I am not sure.:confused: Any help would be greatly appreciated. Thanks Andrew

[sinewave]

Is it the box in ceiling space with the FCU's piped to it? I am not sure.:confused: Any help would be greatly appreciated. Thanks Andrew




Aye aye Captain you are correct! :D

[The captain]

Ok then BC box! got ya. See fast learner. Why would i have 2 faulty sensors in a row like this?? I am not enjoying working on this machine at all. Any answers appreciated. :D

[Thermatech]

In uk we moved on to R410a City Multi products in 2004.
So the R407c YMF-C units are now 3 to 5 years old & therefore would expect so see some minor problems especially if the units have been worked hard.
Have a look at the compressor hours run log by using the SW1 dips on the outdoor control board. Then think about how many miles / km you would have done in your can / van at average speed for the same number of hours.

[The captain]

Ok thanks, i will put her up on the hoist and change the brake pads, machine the disks :D. Check the TH15 sensor in the BC box as well. Thanks everyone.

[The captain]

Faulty TH 15 sensor in BC box 3k ohms @ 20 'C