E464; Is The Compressor Faulty?; Is The Inverter Pcb Faulty? - Samsung RC090MHXEA Service Manual

E464

An E464 fault is caused by the unit tripping out on high compressor current; this is caused by
the compressor having to work excessively hard, the compressor being faulty or the PCB
which drives the compressor being faulty.
Is the unit working too hard.? Very likely in new installations
If the water returning to the unit is not significantly lower in temperature than the flow, in other
words no heat is being rejected in the house. Normally this is caused by, very high flow rates,
low system volume or a short circuit in the system where water can return without going
through any radiators cylinders etc., normally this is caused by bypass valves too close to the
heat pump.
Occasionally we get calls from engineers saying that their units operate fine but a whooshing
sound can be heard from the unit every 40 seconds or so. The sound typically happens when
the air temperature is above zero degrees and the unit is operating at low load conditions.
The whooshing is caused by the unit overheating, to protect itself it dumps refrigerant
internally to reduce the operating pressures, if this operation continues for long periods the
unit will be damaged. Eventually you will see E464 error. The reason for the whooshing is
simple, it happens when the water returning to the unit is not significantly lower in temperature
than the flow, in other words no heat is being rejected in the house.

Is the compressor faulty?

Likely if the unit has been running for ages in condition
above
(Please note that if an inverter PCB has failed, it's normally caused by a faulty fan
motor or compressor: Please refer to E458/E475)
If E464 usually happens at start up, the compressor does not start properly, and usually it
shakes like mad for a few seconds then stops, if this is the case it normally means the
compressor has failed.

Is the inverter PCB faulty?

If the E464 fault occurs, then goes away and comes back
again it usually means the PCB is starting to fail.
When operating correctly the inverter PCB should have 3
LEDs showing, the red one at the front will be on, the
green one below it will be flashing and a green LED in the
middle of the board will be lit. If not the PCB is faulty,
replacing the inverter PCB solve the problem.
E464 is normally caused by a failure in the inverter PCB
PWM Module. You can test it with a multi meter like this,
follow this video link.
https://www.youtube.com/watch?v=P2yPyri4VSg
Or follow instructions on next page
www.freedomhp.co.uk ©G Hendra Nov 18 31