Inverter failure update

[wpowokal]

Update on,,http://www.fieldlines.com/story/2008/5/11/14149/3310

I am amazed on how buried it is now, and have no confidence in many people using "recent activity"

So for anybody interested, I replaced the capacitors with 64V ones and all worked well.

Clearley the magic smoke had escaped from two capacitors, I put it down to excessive heat, caused by my summer temperatures and the rigerous work out I give it in summer.

So now I have a stand by inverter, I suspect electrolitic capacitor failure may be the cause of the demise of many inverters, since it is true for most electronic equipment I see no reason for inverters to be an exception.

allan down under

[BigBreaker]

It is common enough for capacitors to "pop" that I think power electronics devices should make them user replaceable.  That also goes for mosfets, which also seem to lose their magic smoke with some regularity.

Just make sure the caps are empty before messing with them.  A big cap can bite hard.

[DanG]

I'll second you on that, and justified in my opinion - If people respond to post I'm not concerned 'who' replied before the thread gets viewed, that's a 'name-dropper' aspect spoiler in using it for this user, some folks just like seeing their name in print multiple times I guess.

Capacitors failing? There are whole annual productions worth of PC Mainboards that are known to have capacitors with a very short service life that got assembled and distributed anyway - it's the slippery slope of gambling on warranty repair, profiting on field service or a flat rate rebuild once they've been in extended service. Maybe even pushed as far as weekend junkets or bundle of cash for the specification engineer to get a low quality line of capacitors in production (and out of the factory supply chain).

Anyway - good going on getting the sparks back in their cages!

[wpowokal]

Today I started out to put this beast back in service to prove it, but alas no go, bugger.

Took it off the wall and back to the play pen for a better look, the MOSFET bank at the rear looked very gunky so I removed the heatsink to fully expose the control board and MOSFET's.

A prolonged spray with ecectrical cleaner and a blast with air cleaned up most of the gunk. Tried powering it up and no go, bugger again.

Its very wet today and the cleaning spray makes the components cold so moisture soon covered them. So out with the heat gun for a bit of molly codling and it jumped into life.

Re-installed it and the AC voltage was 190 not it's usual 240, grrrrr heat gun again and 240v.

So I put it in service and left the cooling fan O/S overnight to let it warm up.

In the image you can see that the cooling fan blew direct onto the control board.Now the cooling fan was set up to blow and since the relay that starts it was faulty (some time ago) I just ran it full time and as the winter moisture set in, well dust/moisture and electronics don't mix.

So I have fitted a new fan to suck this time and will build a circuit to start it when the inverter is supplying say 1 KW. One can only asume that one of the pots on the control board is voltage adjustment and it got wet or gunk washed into it.

I never said I should be let loose on electronic equipment!

allan down under

[ghurd]

It is a true sine wave inverter?

The 190V seems like a working MSW inverter voltage with a standard meter.

Just mentioned it to keep others with MSW units from thinking their unit is faulty.

G-

[dnix71]

I use electronic ballast cfl lights outside the building at night. They are supposed to be "wet location" suitable. But bugs and moisture cause them to appear dead. WD40 or just bringing them inside for a day to dry out has resurrected more than one.

A heat gun or hair dryer will quickly fix a wet one if I need the light. I've never had to replace caps on the circuit before, but cap failure is common, even on high-end hardware. A Taiwanese firm stole what they thought was an advanced electrolyte formula, when in fact it was "experimental" A lot of computers were recalled because of power supply failures when those caps failed.

http://en.wikipedia.org/wiki/Capacitor_plague

[wpowokal]

Ghurd it is a true sine wave and came progressivly up to full 240 volts over about an hour once in use.

I just have to remember to switch on the fan when loading it until I build the load sensing switch.

allan down under