Refrigerologist
27-05-2017, 02:17 PM
We have recently taken over the maintenance of a building with 8 PURY-P350 outdoor units and a large number of PFFY-P**VLEM-E indoor floor mounted fan coils.
Recently our engineer was called to a problem with a condensate pump that had failed. He found that the installing contractor had wired the mains power neutral through the condensate pump high water level failsafe switch. Worse than this, the pump neutral was wired together with outgoing wire of the failsafe switch on the mains input terminals of the fan coil. The engineer believes that this may have caused a 'racing effect', where the neutral was being connected and disconnected rapidly to the main printed circuit board.
He replaced the faulty pump and for the moment has removed the failsafe from the circuit. Live and neutral are wired direct to the mains power input terminals. 240V is present and the M net bus circuit has a voltage of about 30Volts DC. Neither of the mains power or communications LED's light up. We have replaced the indoor unit printed circuit board, but still neither of the LED's will light up.
We have powered down the m net circuit, BC box and the outdoor unit, but again after reinstating the power and the re-initialising period the LED's still do not light up and the fan coil remains inactive.
Since the first problem 2 other fan coils have suffered the same fate.
No faults are being reported and the fan coils appear on the touch screen controller, but if we try to switch the fan coils on from there they show on for about a minute and then switch off again.
Any ideas as to what or where the problem could be?
I suspect the system memory has been corrupted and the system will need to be rebooted from scratch, but I cannot understand why the PCB mains power LED's do not light up. (The onboard fuses are ok).
Recently our engineer was called to a problem with a condensate pump that had failed. He found that the installing contractor had wired the mains power neutral through the condensate pump high water level failsafe switch. Worse than this, the pump neutral was wired together with outgoing wire of the failsafe switch on the mains input terminals of the fan coil. The engineer believes that this may have caused a 'racing effect', where the neutral was being connected and disconnected rapidly to the main printed circuit board.
He replaced the faulty pump and for the moment has removed the failsafe from the circuit. Live and neutral are wired direct to the mains power input terminals. 240V is present and the M net bus circuit has a voltage of about 30Volts DC. Neither of the mains power or communications LED's light up. We have replaced the indoor unit printed circuit board, but still neither of the LED's will light up.
We have powered down the m net circuit, BC box and the outdoor unit, but again after reinstating the power and the re-initialising period the LED's still do not light up and the fan coil remains inactive.
Since the first problem 2 other fan coils have suffered the same fate.
No faults are being reported and the fan coils appear on the touch screen controller, but if we try to switch the fan coils on from there they show on for about a minute and then switch off again.
Any ideas as to what or where the problem could be?
I suspect the system memory has been corrupted and the system will need to be rebooted from scratch, but I cannot understand why the PCB mains power LED's do not light up. (The onboard fuses are ok).