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damo_666
27-03-2010, 11:22 AM
Hey all, new to these forums and to messing around with split systems. Am qualified refrig mechanic, but only experienced with transport refrigeration (Thermo King, etc).
Anyways...
I have a Fujitsu split system problem, indoor unit turns on okay, and indoor fan runs okay. However, ventured outside... compressor running, but outdoor fan not running. So no surprises to it having no cooling effect. Removed some covers, made sure fan not seized, etc. Noticed @ the 6 terminal motor starter the Neutral wire is very badly damaged and getting hot whilst running. (Burning smell and insulation previously starting to melt)

Just wondering if motor starters are a common problem in a/c units, like if its an internal fault within the starter itself that would cause such a thing or something like the fan motor capacitor?

Looks like its gotten hot only @ Neutral terminal where it clips onto the starter, i was thinking maybe bad connection causing high resistance therefore caused it to heat up, get hot, and cook the starter?

Probably something simple, i havent really had a go at anything to do with split systems before so any advice would be greatly appreciated.

Also, outdoor unit model AOT30R if that helps at all

nike123
27-03-2010, 12:30 PM
There are 3 more letters after R at outdoor unit model#!
Measure the curent at that neutral wire. If current is in limits for that wire size you have bad contact!

Brian_UK
27-03-2010, 10:54 PM
Sounds like a poor contact type burn out.

Mechanical failure due to loose terminal, pinch it tight and restart.

paul_h
29-03-2010, 03:04 AM
Yeah you can get burnt terminals on the soft starter due to wiring getting loose.
But that only affects the compressor, the fan is completely different circuit and not wired through the soft starter.
Either open circuit fan motor or capacitor, or indoor relay/wiring problem.