View Full Version : Mhi 16kw 3phase ducted E42 fault

27-06-2017, 12:24 PM
Hey fellows,
I've got a Mitsubishi heavy that's gone out with a fault code E42.
It's pretty vague what it could be.
It's basically over current on the compressor.

I checked it out earlier, windings on the donk seem ok, it brings on the compressor for maybe 20 seconds then shuts down on fault.

The compressor sounds a little rough.

Has anyone seen this before?

The mhi tech docos are very vague, could be stuffed compressor, power transistor, eev,
Closed service valve, etc...


27-06-2017, 08:01 PM
I checked it out earlier, windings on the donk seem ok,

What do you mean by OK?

27-06-2017, 09:51 PM
They aren't shorted to earth, have the same resistance leg to leg. About 1.2 ohms stone cold.

install monkey
27-06-2017, 10:34 PM
het an inverter checker to test inverter circuit- if you say comp sounds rough its prob pot siezing up causing excessive operating current thus the e42 fault- how long does the comp run for before it stops?- maybe clip the incoming phases to see if you can see excessive running current before it gets converted to the comp terminals

02-07-2017, 09:50 AM
The compressor runs for maybe 20 seconds or so, then shut down.
It all seems to happen too quickly to get an accurate measurement of current on the phases.
As the compressor ramps up.