View Full Version : Capacitors

10-03-2014, 09:54 AM
I was recently called out to diagnose a Actron ducted system were the comp would not run.
I found the run cap and the motor start cap faulty.
I replaced the 50uF cap with a 45uF and then replaced the motor start cap like for like, fitted the caps and system ran all checked Ok. Three days later was called out a gain and the systems Soft - starter was gone. Now the client has had some else fit a new soft starter and a new run cap as he thinks the 45uF cap has taken out the soft starter due to using a low uF reading cap and this has resulted in the soft - starter failing. even taking in account of the +- 5% this is still only 2.5 uF shy of whats required. now he wants me to pay for the other tradie to replace the soft - stare and cap???

can some please shed some light on this as I think this is not the cause of the soft - starter failure.

Rob White
10-03-2014, 10:45 AM

Its hard one to call.

The 45 uF is not a 50 uF and they put a 50 uF on for a reason??

Did the smaller capacitor cause the soft start to fail, I don't know,
it might have been a series of unfortunate events and the soft start
might have failed anyway??

No help to you, I know.

The customer might have a valid case, he might just be trying it on
but because you did not fit the correct capacitor, you are out on a limb
and he feels justified to ask you to pay for the additional repairs.



10-03-2014, 10:48 AM
Personally, I wouldn't be paying until solid proof was available regarding the cause of the failure. Maybe you could suggest that the failed soft start is sent back to the manufacturer for examination?

Here's a link to a Blog (http://yorkcentraltechtalk.wordpress.com/2012/03/30/everything-you-ever-wanted-to-know-about-capacitors/) by a Pro...he will also answer questions via his blog.

10-03-2014, 08:13 PM
thanks guys

monkey spanners
10-03-2014, 10:55 PM
Can't see a run capacitor being 5uf low having much effect on a soft starter, surely its only in circuit during starting when the run and start capacitors are both in circuit, theres generally such a large tolerance on start capacitors that i expect your replacements were in spec when starting. (worked on a copleand compressor that had had a 25uf fitted where a 60uf should have been, had been like it three years, i changed it but it goes to show)
I keep a range of capacitors on the van, you can always join a couple together to get the correct rating, e.g. 45+5, 20+30 etc

More likely it was old age or the damage was one before the original call.

I wouldn't pay either, he should have called you back to fix it. How can you warranty stuff when its had third parties working on it in the interim?