!!big Daikin Problem!! Codes,u4,pj, And E0

[airconengineer]

Hi Guys
Got a daikin A/C split with a indoor wall mounted unit (R410A). installed by another company.Never worked i got called in showing a fault U4. past experiance of a U4 code on the daikin means outdoor PCB. Checked outoor unit and LED A was not lighting which also indicates outoor pcb. Bought a new pcb and came with a capacitor which had to be added to the pcb. Changed the pcb but the fuse blew straight away. Discoverd mix up in wiring and sorted out wiring. then coming up code PJ as soon as i switched it on.I fitted the capacitor wire which came with the unit and now it is coming up with the code E0 as soon as i switch it on rang up daikin tech and they said to check all the safety devices to see if they all are sending 240v to the devices and 240v coming back. all fine except only 24v being sent and coming back to the low pressure device.the pcb is fine what do i do now??? PLEASE HELP

[puddleboy3]

Your first fault code U4 Basically means the indoor unit is not communicating with the outdoor!. PJ means you have changed the PCB and not installed the capacity adapter with the new board. E0 means that one of the outdoor safetys have tripped. To help you anymore we would need the model numbers of the system.

[airconengineer]

i know the indoor model No is
FAQ71BUV1B

i will have to find the outdoor i have it written somewhere

[airconengineer]

the outdoor model No is
RR71B7V3B

thanks for the quick response

[frank]

the outdoor model No is
RR71B7V3B

thanks for the quick response

Single phase non-inverter compressor.

U4 code on the daikin means outdoor PCB.

Incorrect. U4 means that the indoor unit cannot communicate with the outdoor unit.

Changed the pcb but the fuse blew straight away.

Doh!

the pcb is fine what do i do now

Are you now saying that the outdoor pcb LED is flashing (green one) and the U4 fault has gone? is the only fault code now EO?

Have you carefully checked the connectors on the new pcb (the grey ones)? Does the system run first then fault with EO or refuse to run?

If it refuses to run from cold and just shows an EO then I would suspect that you have got a wiring problem. Pull off the grey wire connectors and check for continuity (through the fan and compressor). If you have continuity here then it may be that the connectors are not seated correctly or are on the wrong pins

[airconengineer]

yes the u4 fault has gone away now the problem is the EO code. and it refuses to run even in fan only mode the wiring is correct and im sure the pcb connectors are fine.

[airconengineer]

thanks for the lecture lads. i know how to use a multimeter so rest assured. i was thinkin more in the lines of being able to override the device to test which one of the three is broken

[frank]

thanks for the lecture lads. i know how to use a multimeter so rest assured. i was thinkin more in the lines of being able to override the device to test which one of the three is broken

Frank wrote

An interuption to the 240 volt being sent out on one grey wire and back on the other will give an EO stoppage.

All the clues are there - you're just not reading them

[airconengineer]

ive written previously about that

"my main concern is only 24v being sent and coming back from the low pressure switch but the rest having 240v"

[cooldude]

sounds like compressor, capacitors or fan motor to me

[sinewave]

sounds like compressor, capacitors or fan motor to me

Nothing like casting your Net wide is there?