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mike_k
18th February 2013, 11:02 PM
I've recently picked up an ex army 2.5 kva generator.


https://www.aulro.com/afvb/images/imported/2013/02/408.jpg
The motor now runs really well, I wish I could say the same for the electrical side.


https://www.aulro.com/afvb/images/imported/2013/02/409.jpg
Does anyone out there have a manual for one of these, or know of any of the same type? A wiring diagram or troubleshooting info would be terrific.

https://www.aulro.com/afvb/images/imported/2013/02/410.jpg

Hopefully it is something simple, any info much appreciated.

https://www.aulro.com/afvb/images/imported/2013/02/411.jpg

If anyone is interested, I'm happy to post what I know about this thing. (which is not very much at the moment)

Apologies for cluttering up the forum, info seems a bit scarce on these things!

Cheers,

Mike.

mike_k
20th February 2013, 09:36 PM
There are a few views on this, so I'll post a quick update.

Apologies for the numerous pictures, but they tell the story ....sort of.

As I said, the motor is quite good, and after a bit of a clean up, some new fuel gaskets and a magneto adjustment, it runs well.

The power side though, is not currently working.

When running, and selected to 240 volts, the volts read 25 volts AC approx, with no frequency or load. This is with the 'Mains' switch On and all of the socket switches off.

When one of the sockets is switched on, the volts drop to zero, the frequency meter just reads on the lower left side and the load comes up to about 10%.

It did work normally once with correct volts and frequency, but when one of the sockets was selected on, the fault came back.

So I know that it does work, well it did once.

I checked the cable between the generator and the control box, it was fine.

All the switches work according to my multimeter.

I've had a look in the control box,

https://www.aulro.com/afvb/images/imported/2013/02/310.jpg


Back of control panel,

https://www.aulro.com/afvb/images/imported/2013/02/311.jpg


Interior of control box


https://www.aulro.com/afvb/images/imported/2013/02/312.jpg

It all looks okay, no loose or burnt wiring, no water damage,

https://www.aulro.com/afvb/images/imported/2013/02/313.jpg

No obvious burnt or cactus components,

https://www.aulro.com/afvb/images/imported/2013/02/314.jpg

https://www.aulro.com/afvb/images/imported/2013/02/315.jpg

Complicated but looks fixable....


I removed the generator end cover,

https://www.aulro.com/afvb/images/imported/2013/02/316.jpg


This panel had quite a bit of white powdery corrosion, sorry no before pic.

https://www.aulro.com/afvb/images/imported/2013/02/317.jpg

I carefully cleaned it up, looks a lot better than it did.

A bit hard to see, but the transistor (if thats what it is) and 2 of these terminals are insulated from the plate with small plastic (mica?)washers so that they are insulated from the other 2 terminals. This was where the corrosion was, possibly grounding the insulated terminals. The wires also have an insulating ring to stop them touching the plate where they go through it.

Unfortunately, cleaning up the corrosion didn't help, still the same lack of output.

The brushes don't look too bad,

https://www.aulro.com/afvb/images/imported/2013/02/318.jpg

A bit out of my depth at the moment, I have contacted the RAEME museum and they will ask around to see if they can come up with a wiring diagram or any manuals etc. for this thing.

If any of this jogs anyone's memory or if any one knows of any parts for one of these lying around, I'd be very grateful, It would be terrific to get this up and running again.

Cheers,

Mike.

100 td
28th February 2013, 11:32 AM
REMEMBER_ Safety First.
These generators can kill you. The information provided below is only to be carried out by a competent and certified electrician.

The first one, the transistors are actually diodes, looks like they have been replaced previously (or is that just from you), check them with a diode tester on a multimeter.
The fact that you say you had correct volts once is promising!
Look for a short in your socket, and or follow the info below.

The second one (and may relate to the first), when generators sit around for a long time they loose their residual magnetism and need to be "flashed" across the brushes to produce some magnetism in the rotor so they can start generating some voltage which is then fed back into the rotor to produce more. generally this was done with "little" 9v battery, it was enough to fire them up. Polarity need to be correct. Alternatively a 12v car battery with a bulb in series to limit current.

Sometime just letting them run for 5 to 10 minutes at 3000 rpm with nothing plugged in, or turned on, the tiny bit of magnetism will slowly build up and away they go, but generally they would need to be flashed.
When adding load do it slowly and watch voltage response to small increments in load.

weeds
28th February 2013, 11:58 AM
i had to fixed the mechanical side of these things way to many times than i would like to remember.........as boffins were thin on the ground we would just grab distro boxes off the spare for boken gennies, not much help i know

just make sure you have the joining cable pushed fully home

i like the fuel filter mod.......

whats your plans for it?

mike_k
7th March 2013, 11:11 PM
Thanks for your replies 100 td and Kelvin,

I've been really busy at work, sorry about the delay in posting but I'm hopefully about to make some progress on this thing.

I had some very good news just under a week ago...

I was contacted by someone who very kindly sent me copies of the army manuals for these gensets. This would have taken some considerable time and effort, and I am extremely grateful for this persons very kind help.

So now armed with all the details, I'll try some of the troubleshooting steps and hopefully make some power.....

The first thing I'll try is as suggested by 100 td - excitation renewal.

Apparently the permanent magnets that power the field on the 12 volt side can lose their magnetism if not used for a while, causing the low voltage side to fail which in turn fails the higher voltage ac fields. (sounds like I know what I'm talking about but this is not really true (!)).

So there is a procedure to reenergise the field, which is a likely fault with this unit.

It also has built in short circuit protection and I found that someone in the past soldered a wire from one side of a power socket directly to the earth terminal. Not a good idea, and does not appear in my newly acquired wiring diagrams. With this wire removed, it must help.

I'll fire it up again tomorrow and see what happens...

I am very aware of the lethal voltages, and being very careful.

Kelvin, I'm impressed with the motor, it runs very smoothly and there is no smoke from the exhaust. I just need to check that the governor is set correctly, I've cleaned up the adjusting rod and will check it tomorrow.

The fuel filter was fairly old and may have been an in service thing - I've replaced it with a new one , the one on it was full of red dirt, jerry can red paint and other non fuel stuff.

The plan for it is,

Backup power for my electric water pump on the house for the fire plan, (we do have other pumps etc)

Good power for fencing etc around the place,

I'll give it a fresh coat of paint and get rid of the surface rust (not a big fan of rust),

and I'm looking forward to having a really well made genset - try buying one of these from China!

Also it will look terrific in my 2A army LWB - see there is a Land Rover connection.

I'll let you know how I go,

Cheers,

Mike.

mike_k
15th March 2013, 09:21 PM
Another quick update, the genset is now up and running!

Initially I couldn't get it to excite, so I checked the slip rings - they were dirty.
After a clean up,the excitation procedure worked, and I had both 120 and 240 volts on the meter when selected.

Progress.

Unfortunately, whenever I switched on of the 240 volt socket switches on, there was a dead short. With the help of someone who knew what they were doing, we found that the capacitors across the sockets were shorting out. After 40 years, fair enough I guess.

So we temporarily removed them and we then had a working unit.:D
The capacitors are only for RF screening,so they don't affect the operation of the system.

Couldn't have done it without some very kind help.

Next is a bit of a repaint / touch up and I'll get rid of the rusty bits.

I'm also on the lookout for a toolbox that fits the frame, and apparently they had a flexy exhaust pipe extentsion.

I found some old posts that mentioned these units at disposal shops with all of their spares etc. intact.

If anyone sees any of this stuff around, let me know....

Very satisfying to get this 40 year old bit of kit up and running again, hopefully we will have a blackout this weekend. (!)

Thanks again Kelvin and 100 td for your replies.


Cheers,

Mike.

100 td
23rd March 2013, 04:15 PM
Look for a short in your socket.......

.......when generators sit around for a long time they loose their residual magnetism and need to be "flashed" across the brushes


................. found that the capacitors across the sockets were shorting out.
..........,the excitation procedure worked, and I had both 120 and 240 volts on the meter when selected.
Mike.
I think I'd better buy a lottery ticket!

weeds
23rd March 2013, 05:59 PM
how are the engine moats?

i threw away a set a while ago

when we used to run out of stock we removed the backing plates on the mounts, tracked down some suitable sized springs, cut them down to suit. the tricky bits is holding it all together and getting the bolts back into place

mike_k
29th March 2013, 10:46 PM
100 td, good luck in this weeks lotto, you're on a roll.......

What are your numbers?:D

Kelvin, funny you should mention the mounts, I had a quick look last week.

I wish you still had your ones, I could have used them......

These 4 are from the generator end, which obviously cops a hiding.

https://www.aulro.com/afvb/images/imported/2013/03/76.jpg

All of the springs have collapsed, and the rubber mounts inside don't feel good either.

I might take one apart and try your big spring fix, unless these have already had it done!

A closer look at the really cactus one...

https://www.aulro.com/afvb/images/imported/2013/03/77.jpg

The other 4 are a bit better though, these are from the motor end.

https://www.aulro.com/afvb/images/imported/2013/03/78.jpg

The last four are reusable, they are missing thier rubber grommets at the moment while they are painted.

I had a bit of a look around the net and was amazed to find someone in Israel selling 4 replacements. He has a pretty big eBay store that sells all sorts of ex mil gear including a lot of aircraft stuff. A bit of history there.

They are on their way, not a bad price, and free postage. Not a bad find for 40 year old parts, hopefully they will do the job.

At the moment the genset is in a million bits, it takes up a bit of bench space when its apart!

Looking forward to getting some green paint on it all and start re- assembling.

Thanks for the replies again,

Cheers,

Mike.

Domokelly
12th October 2019, 01:36 PM
Hi Guys,

I've just picked up the same generator set. Looks like a well made piece of kit! Definitely beats the cheap Bunnings sets.

But I was just wondering if anyone might have a wiring diagram / operating manual they might be able to send to me?

Kind regards,

Dom

4bee
12th October 2019, 03:02 PM
I'm also on the lookout for a toolbox that fits the frame, and apparently they had a flexy exhaust pipe extentsion.

Similar Gennies I was involved with in RA Sigs had the flexible exhaust approx. 1.5m in length from memory. This was used so the end could be dropped into a hole in the ground for quieter Operation at night.

I never spotted any wayward & inquisitive VC so I guess it must have worked, but I suppose they would have been a bit of a rarity at Cultana or Alligator Gorge SA anyway.[biggrin]

4bee
12th October 2019, 03:06 PM
I'm also on the lookout for a toolbox that fits the frame, and apparently they had a flexy exhaust pipe extentsion.

Similar Gennies I was involved with in RA Sigs had the flexible exhaust approx. 1.5m in length from memory. This was used so the end could be dropped into a hole in the ground for quieter Operation at night.

I never spotted any wayward & inquisitive VC so I guess it must have worked, but I suppose they would have been a bit of a rarity at Cultana or Alligator Gorge, Wilmington anyway.[biggrin]

Blknight.aus
12th October 2019, 06:22 PM
Similar Gennies I was involved with in RA Sigs had the flexible exhaust approx. 1.5m in length from memory. This was used so the end could be dropped into a hole in the ground for quieter Operation at night.

I never spotted any wayward & inquisitive VC so I guess it must have worked, but I suppose they would have been a bit of a rarity at Cultana or Alligator Gorge, Wilmington anyway.[biggrin]

worked better the other way around....

drop the genny in a hole, dig a trench for the exhaust and set it up so the exhuast side was down wind.... mound up the windwards side a little and cover with a pallet...

4bee
12th October 2019, 08:35 PM
Probably Dave.

A bit late now for me but it would have been more convenient attached to an Engineer's Detachment with access to a small excavator. [bigsad]

'When I say dig, all you have to do is ask "How big?"

Ah, the good olde days.


FWIW, This post got me off my arse to stoke up my ex-Telecom B & S genny & give her a run for a bit. Still works 1st pull.[bigsmile]