no volts generator

[wheresmejumper]

I have a lister genny, no output at all.looks like 2 caps and maybe avr? Brushes good

how do I go about faultfinding this?

 

[piman]

Hello Where's me jumper,

firstly a basic continuity check on the stator and rotor windings. If it's been stood for some time it may have lost the residual magnetism in the rotor so injecting some voltage to the brushes may kick it into life? Trouble is I don't know what sort of voltage, maybe a car battery would do it? Are there any details of field voltage on the name plate (If there is one?)

Alec

 

[wristpin]

12volt car battery has always worked for me!

 

[wheresmejumper]

Ill check for continuity first thing tomorrow.theres no nameplate I dont think.

whats the method for giving it a shot of 12v?

 

[the snooper]

its possible that the alternator is a markon

 

[drivewasher]

It does look like a Markon generator. Possibly an SC21

If the rotor hasn't been removed from the stator or vise versa I doubt it will have lost residual magnetism.
The aluminium box filled with resin with 4 treminals on it is the favorite culprit. It's an AVR (automatic voltage tegulator)
I think I have a new one in my might come in handy one day pile. Ill have a look tomoz see if I've not given it away

 

[drivewasher]

Has it worked as it is now? If not post a better pic of the top box. 4 wires out the alternator are 2 windings off the stator, 110v is the 2 windings in parallel & 220v is the 2 windings in series.
I recently binned all my generator manuals annd drawings as I not used em for about 15 yrs.

 

[wheresmejumper]

I picked it up for scrap price as a non runner.dont know when it last worked.
Ill take a pic of wiring tomorrow, but it looks as if its not been messed with.
is there a reading before and after the avr I can compare to see if its the problem?

 

[wheresmejumper]

Update on this.had to get the rotor rewound, and new avr.
€260 repair but great yoke now

 

[Rig Pig]

Ouch - but at least it works now

 

[the snooper]

Update on this.had to get the rotor rewound, and new avr.
€260 repair but great yoke now

I think you could have bought a mec alte spa alternator for less, but at least you got it working

 

[Wedg1e]

I scored a 2.2kW Honda-driven Leroy Somer unit recently; no output. I know the guy who looked at it a few years ago and decided the windings were toast but they looked OK when I metered them out; I found the alternator manual online at the same time as a Google search threw up the dodge of flashing the windings with a car battery (ah the good old days of Austin Mini generators ).
I used a spare burglar alarm battery, two bits of wire up the spout, flash flash, pulled the cord and hey presto, 240V

 

[wheresmejumper]

I think you could have bought a mec alte spa alternator for less, but at least you got it working

I had a look around after I found out about the rotor short, theres not many 6kva alternators around for the price of the repair.
I also wanted to give the rewind guy some work.i have some projects lined up and he'll be a useful contact to have

 

[fenman]

(ah the good old days of Austin Mini generators ).
I used a spare burglar alarm battery, two bits of wire up the spout, please explain how to do this

 

[Robotstar5]

How to flash a generator - link

 

[Jim Davey]

Hello Where's me jumper,

firstly a basic continuity check on the stator and rotor windings. If it's been stood for some time it may have lost the residual magnetism in the rotor so injecting some voltage to the brushes may kick it into life? Trouble is I don't know what sort of voltage, maybe a car battery would do it? Are there any details of field voltage on the name plate (If there is one?)

Alec

You need to get the polarity right but a quick flash off a car battery onto each brush will restore function if the genny has lost residual magnetism and won't self excite. It will spark a little and you only need hold the wire on for a second or so then it should run just fine (that's if that's the original issue to start with).

EDIT: Just seen the above, more thorough explanation, best of luck with it.

 

[the snooper]

I picked it up for scrap price as a non runner.dont know when it last worked.
Ill take a pic of wiring tomorrow, but it looks as if its not been messed with.
is there a reading before and after the avr I can compare to see if its the problem?

which lister engine does it have ?

 

[Wedg1e]

(ah the good old days of Austin Mini generators ).
I used a spare burglar alarm battery, two bits of wire up the spout, please explain how to do this

As Robotstar's response above, really. However the Leroy-Somer has no AVR, just a couple of silicon diodes.
Oddly I was just talking to a guy at work about the same subject and he said another way to do it is to connect a suitable power tool, start the genny and spin the power tool up. Claims he did it by using a die grinder with an old burr in it and ran the burr along the floor (with the tool switched on). Apparently the small voltage created in the windings of the power tool is enough to stimulate the generator into working again. Obviously you can tell if it's worked as the power tool will start working.
I can see how it might work but I only have the word of a stranger for it I do wonder if a variable-speed power tool might not work in this instance as the speed regulating widgetry might get in the way of the electrons...

 

[fenman]

Thanks guys will give it a go

 

[wheresmejumper]

which lister engine does it have ?

Its an ac1
5kva, not 6