Anybody know anything about generators?

[SB118]

A friend of mine has asked me to have a look at his generator which died while he was doing some welding.

It only puts out a voltage when it's reved hard, i'm thinking regulator/govenor fault? Or the surge load from the welder has melted the windings?

Did a quick vid to show the behavior, you might want to turn down your speakers though!

I'm guessing this bit is the voltage regulator?

The purple wires are the 12v side of things, read at 1v until it's reved, then it jumps to 14v.

My understanding of these things runs out shortly after i take the cover off the end of the alternator, help!

 

[Lethagized]

I would say he's overloaded it and buggered it completley. What is the maximim capacity rating of the generator? And what was the rating of the welder he was using?

 

[SB118]

It's a 2kw cont/2.4kw peak unit, dunno about the welder.

 

[Al-Ectrician]

have a sniff, does anything smell burnt out ?

Al

 

[SB118]

Nope, first thing i did when i opened it up.

 

[Jotun]

Well I don't know much about generators really, but the CBB61 is a capacitor, google agrees with this too. I have no idea if they symptoms you describe are typical of a regulator fault though.

In my experience a regulator will often have 3 connections (Vin, Vout and Ground), and the component you photographed only has 2 as far as I can see. I'd also expect a regulator would have a rather large heatsink attatched to it.

 

[Al-Ectrician]

As jotun says your first image shows a 350VAC 14microfarad capacitor.
This could be disconnected and tested, If you know how.

BE CAREFUL Capacitors hold their charge and are dangerous, Get some help from a local engineer.

 

[Jonny69]

I'd say the welder has probably killed it. I've been trying to run my 150A MIG at about 2/3 power on a 5.5KVA Honda 4-stroke generator and it just can't keep up with the sudden power requirements and stalls.

It should show full voltage at idle and the revs will increase as you load it up. I was told to start it up with the power switched off, then flick the the switches on once it's running or it will damage the circuits. Has he been doing that?

You get special welder-generators, a welder with a built in gennie, which I guess hold a reserve for the initial kick or rev right up in anticipation. I saw one of these once and it welded no problems.

 

[SB118]

It should show full voltage at idle and the revs will increase as you load it up. I was told to start it up with the power switched off, then flick the the switches on once it's running or it will damage the circuits. Has he been doing that?

It used to show a steady voltage. This one needs the circuit on to feed the coil pack. I was thinking it was the welder surge that had done it in. I've had some guys saying i could try and restart the magnetic field by putting 12v through the coils for a moment. Nothing to lose i suppose.