View Full Version : Inverter board

Philip d1
25-02-2017, 11:01 PM
Hi there I was wondering mcb keeps tripping, windings are ok not mechanical seized I was wondering would my inverter board trip the breaker if faulty the second I turn isolator at outdoor mcb trips at mains

25-02-2017, 11:09 PM
On what system? I assume an AC system and not a VSD?

If you mean on an AC system then yes it could do, especially if the noise filter board has also failed.

Philip d1
25-02-2017, 11:16 PM
Yes on a/c system it's a 3 phase compressor first I thought short circuit or grounded but resistance on windings are good I had 2.5 ohms across each winding and carried out megger test so then I thought mechanical but it's tripping even before compressor is called for.

install monkey
26-02-2017, 08:45 AM
what type of breaker ? b type typically for lights and sockets c an d type for ac units /motors- will take more of an inrush

26-02-2017, 08:51 AM
You have checked the 3 phase rotary isolator haven't you? There could be a dead short in there, maybe water has got in.
It's worth confirming that first.

Philip d1
26-02-2017, 10:15 AM
It's an c rated breaker..I need to call back and go through everything as I don't believe my compressor is causing the fault.is it possible winding insulation it badly damaged making compressor pull more current without giving me a short circuit or ground reading that there about to go.

26-02-2017, 03:01 PM
If the winding insulation was bad, you would have picked it up on the insulation and resistance test.

Why not disconnect the compressor terminals to rule the compressor out for certain.

Philip d1
26-02-2017, 04:08 PM
Il have to do that in the morning first thing and go form there.thanks for the help

install monkey
26-02-2017, 08:50 PM
inverter would detect overcurrent before a breaker trips

Philip d1
28-02-2017, 04:33 PM
Ended up being inverter board and noise filter blown.i disconnected compressor still tripping