Fujitsu

[Abe]

Went out to a 7Kw Fujitsu Cassette Air Conditioning Heat Pump today.

All I heard was a hum, come from the compresor...........and then it stopped.

It did not shudder or shake. It just hummed for around 15secs or so...........and then stopped humming.

Condenser fan continued to run.

I told customer he needs a new compressor. But, I am wary......He told me it never worked right in cooling mode since it was installed two years ago.

It worked ok in heating...............apparently

What if I change the compressor and it blows , because of a fault with say the three way valve..........

Maybe the install was bad.........too much R410 put in......

Im not sure............

Would it be better just to fit a new Outdoor unit?
Is it the compressor?

What other checks should I have carried out.

I am not familiar with Fujitsu on troubleshooting.......

Any help appreciated

Mode No AOY25UNAKL
Serial No T 000348

R410
7Kw

[Brian_UK]

I'd go with a new unit.

If you have to change a compressor then you should also do the reversing valve. One may have killed the other but you don't know which one did it first.

Tell the customer that with the material and labour costs plus the lack of warranty that new is cheaper/better in the long run.

[Andy W]

If it is a current condensing unit a unit will work out a few hundred pound more fitted! I had a 14kw Fujitsu I changed a compressor on and the bugger went down on both blocked filter driers, I spent hours with it, when I priced out a complete outdoor unit which would of saved me a load of hassle it was only £250 more than a compressor and contactor and bear in mind it had a new rev valve, 2 fan motors, circuit board.........I was horrified.

[Renato RR]

Well 15 sec is enought to check 4V by thermometer.Also the gauges would tell something.If it is 4V than suction pressure would be higher then normal.But you know all that.

Renato

[Temprite]

G'day Abe.

Have you checked the run capacitor?

Does it have a soft start?

Have had a similar problem where a unit under warranty lost 2 compressors over a 2 year period. Turned out to be a partial restriction of the capillary assembly.

Symptoms was a unit that appeared to work although not quite properly with a slightly lower than normal suction pressure.Compressor would occasionly fail on thermal due to lack of compressor cooling.

Regards.

[slingblade]

Sounds like it is siezed, what was the current draw?
it is faster and easier to replace to cond unit rather than the pot. its your choice, but i know what i would do.

[Abe]

Ive quoted a new Unit.......895.00 List

Compressor alone is around 300.00 mark

Does not make sense to fit compressor in case there are other underlying probs with say, restriction in cap tube, three way valve not closing tight, etc.

I dont want sleepless nights and going back to and fro to the unit.

This way Ill fit a new outdoor unit, and use the old one , convert it to use in a cold room or a air handling situation.

The blanket wrapped around the compressor. It only served to make the compressor baking hot.

Is it acceptable practice to remove it completely....

Ok, it will make the sound level increase, but what other purpose does it serve???

[Abe]

Well 15 sec is enought to check 4V by thermometer.Also the gauges would tell something.If it is 4V than suction pressure would be higher then normal.But you know all that.

Renato

Renato

Can you elaborate please.

15 secs is enough to check 4v by thermometer , of what?

Gauges dont move, compressor does not start, it only hums

Much appreciated

Thx

[Renato RR]

Ok.I miss understend you.So compressor doesnt start at all.Then did you check resistance betwen C,S and R.Firs remove start relay and measure with unimer C-S,S-R,C-R.But condenser fan shouldnt start if compressor doesnt run.

Seams easy but then again it is problem to come again to machine becose you can charge that.

Renato

[Daddy Cool]

The blanket wrapped around the compressor. It only served to make the compressor baking hot.

Is it acceptable practice to remove it completely....

Ok, it will make the sound level increase, but what other purpose does it serve???

i don't know about Fujitsu, but Hitachi always said to leave it in place as it served to stop you burning your arm when you stuck it in, they used to run red hot.