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wilks
07-06-2011, 07:31 PM
Hello all
Got called out today to a city multi vrf on r407c. It was showing a 5104 fault which was outdoor thermister error , I found which thermister which was causing the fault, it was the thermister on the accumulator higher not lower I think . When I looked closer at the pipe or mini accumulator that the thermister was connected to I found some tiny heater cord wrapped around it, the heater cord was melted and damaged . Upon checking the the relay that powers the heater I found that it was welded closed, it's only ment to pulse on and off. When I unplugged the heater the original fault cleared and the unit ran for about 40 mins, then I got 1500 fault ( too much compressor cooling). Could the to faults be related ?? Thanks lads

wilks
07-06-2011, 07:53 PM
My thinking is that the heater being on all the time caused the thermister to give dodgy readings, as I say when I unplugged the heater the thermister cooled and the unit ran.I also notice that all of the 15 indoor filters were blocked solid . Maybe this was to was adding to the overcharge 1500 cult code problem??thanks fOr your help .

install monkey
07-06-2011, 08:02 PM
THHS>
If a heat sink (THHS) temperature
of -40
°C is detected just after the
inverter starts or during inverter
operation.probably due to your blocked filters causing the 5104 fault

wilks
07-06-2011, 08:38 PM
Hello mate .
I've ordered a new board an heater cord for it , because the relay is stuck . we are doing the maintenance when we get the board. Do you know why they have this heater? You think the the original 5104 fault could be down to the filters then? I havent seen filters as dirty in 16 years like!

install monkey
07-06-2011, 08:50 PM
yep with blocked filters and usually a high demand for cooling the compressor is gonna chug its nuts off due to the demand and then ur accumulator temp drops below -40 and then the alarm after 10mins of operation below threshold-ps u have mail

wilks
07-06-2011, 09:12 PM
Thanks for the manual mate . Helps alot .