Panasonic help

[marc5180]

Hi all
i was sent today to change a compressor and an inverter board on a Panasonic cu-280mx51xp 2 pipe VRF, with 2 compressors. The refigerant had been changed in the factory from R22 to R407c when it was first installed. So after i had fitted the compressor and inverter board i recharged with what was written on the label on the condensor 21.7kg of R407c. I got the charge in then turned the power on and started her up. On my guages i was getting 6 bar on the suction (85psi) and 14 bar (200psi) on the discharge. I felt the discharge line leaving the compressor and it was luke warm, i then turned the fans off for a few mins to check if the compressor was ok ( to see if it built up the head pressure, which it did slowly) I left it running for about half an hour in which time i put all of the indoors ( there are 7 indoors in total) on test mode. In all this time the compressor that i changed didnt come on once. i turned the power off as i noticed that the inverter compressor connection was a bit loose on the inverter board so i tightened it up then turned the power back on but nothing happened. So i went upstairs and found each one of the controllers flashing "E27" which indicates numerous things from reverse phase protection to compressor open phase. I spoke to a few guys from Panasonic but didnt really get much help. One suggested in could be a new outdoor board, the other guy sugested it could be a transmission error between the indoor units. Any help from you guys would be appreciated
Cheers

[Sledge]

I am not familiar with the panasonic, but can make a couple of guesses,

If you are powering the compressor through an inverter, does that mean that you are varying the speed of the compressor motor based on load? If so you need to get the compressor to run at full nameplate speed, before you can consider the pressures.

I would attempt to run the compressors without all the hi-tech gadgets. This would allow you to differentiate between a refrigeration side fault or a problem with the gadgets.
Obviously you have to take precautions, ensure all the safeties are functioning, and not bypassed for the test, ensure the chiller is loaded, ensure the cond fans are running etc

[marc5180]

Im not able to get the compressors to start up until the fault code is cleared though and i dont know what has caused the fault code