air con fault

[bellaman]

hi all i have a problem with a air conditioning unit i installed a few years ago,there are two indoor cassette units and two outdoor units both units are working off one remote both units are working fine up until lately one indoor is not coming on when it should be,i checked the remote for errors and it showed up an f1 error i reset the power on the outdoor the isolater and it ran ok for a few days but it has happened again.they are two mitsubishi elec units 407c i was wondering if anyone had this problem before and if so could they let me know what action they took some help would be greatly apreciated thanks.

[croc1774]

Hi would be helpfu if had model number of indoor units and outdoor units.

f1 error Mr Slim R407c Reverse phase detection, Power supply and indoor/outdoor unit connecting wire converse connection.

check power supply phase to make sure correct
check inter connecting cable is wired correct.
check remote cables are wired correct.


how have you connected conrols between units ?
regards Bellaman

[bellaman]

thanks croc1774 for that information the way we wired the control was from one to the other and then to the remote and the model for the outdoor is puh-p125ygaa and indoor is pla-rp125aa i checked the phases on the outdoors and they seem ok.
thanks and any help would be great..

[hyperion]

Would suggest that you may have had a power spike which has confused the phase detection module or possibly a loose connection in the power wiring.

[bellaman]

what if i were to change around L1 and L2 would this do any harm to the unit

[paul_h]

No harm in doing that.

Common here for three phase units to get a phase error because the power company mucked about.
The first thing you do is reset the power, if that works the error was just caused by losing a phase for a short time.

If that doesn't work, then the next thing to try is to swap 2 phases like your suggesting in case the power company did that.

If that still doesn't work, then the PCB is suspect, as it isn't working with any combination of power supply phases.

[bellaman]

changed over L1 and L2 that didn't work remote came up flashing so changed it back to the way it was swaped over the pcb on the outdoor with another unit and the fault is still coming up when i check for faults unit is working now but will probably stop again can't get in to work on the indoor today as there is a function on.

[cosmaniac]

if u check on the outdoor units door there is a label which tells u all the meanings of the code there is 2 led s on the outdoor board green and red if i am not mistaken but thats a 125 unit is it the inverter type?