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Author Topic: Recommissioning a Lister ST2 with Brush Generator  (Read 709 times)

TGC61

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Recommissioning a Lister ST2 with Brush Generator
« on: October 04, 2022, 09:09:21 AM »
Hello all - glad to have found this forum. I have an ST2 with SOM attached to the wiring of my house that has not been used for a couple of decades. The engine I know works very well but there are likely issues with the generator and wiring and so I was hoping there was somebody who had experience of this and can advise what to look out for. I have a very capable guy locally who is helping with this but I imagine it may be a process!

It was installed new in 1974 and has had very little use.

ajaffa1

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Re: Recommissioning a Lister ST2 with Brush Generator
« Reply #1 on: October 04, 2022, 09:27:58 PM »
G`day TGC61, welcome to the forum. The ST2 SOM is a very nice robust unit, I restored one about 8 years ago. I have posted a great deal of information about the brush generator and it`s control panel, in the past. If you search the old threads you should find everything you need to know.
Very happy to give advice, please post photos of what have got and what you are worried about.

Bob

TGC61

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Re: Recommissioning a Lister ST2 with Brush Generator
« Reply #2 on: October 05, 2022, 06:01:33 AM »
Thanks Bob

I've attached an image and will take a look at your earlier posts. When started about ten years ago I have a memory of sparking from the front end but we didn't have this last week. I've not put any load on it.

Thanks again

Tom
« Last Edit: October 08, 2022, 03:17:22 PM by TGC61 »

TGC61

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Re: Recommissioning a Lister ST2 with Brush Generator
« Reply #3 on: October 08, 2022, 03:19:19 PM »
Hi Bob - I've added a few more images of the front end for your comment

ajaffa1

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Re: Recommissioning a Lister ST2 with Brush Generator
« Reply #4 on: October 08, 2022, 10:38:03 PM »
Hi TGC61, yep, that looks exactly the same as mine did when I started. Every thing looks to be intact, just dirty. There are two slip rings with four brushes, these are part of the generating system. There is a commutator ring with another set of brushes, this is a built in starter motor/dynamo.
These are a compounding generator, the output voltage can be adjusted using the two variable resistors/rheostats(one shown in your last photo). The other resistor is behind the other plastic cover along with an old selenium bridge rectifier, which will need to be replaced with a modern silicon rectifier. Selenium is very toxic, it gives off a smell a bit like garlic, please be careful.
The two small aluminium condensers at the very top are radio frequency suppressors, they are probably defunct and should be replaced or simply discarded. They are not really necessary unless you live in a built up area where radio interference might upset the neighbors.
I striped mine down completely because the grease in the two bearings had oxidized into a solid, while I had the armature out I put it in a lathe and gave the commutator and slip rings a very fine skim. I also gave all the cloth insulation tape on the copper windings a fresh coat of polyurethane varnish.
Before doing anything else get yourself a cheap multimeter and check the continuity of all the copper windings. There is no point in spending time and money if the generator is burned out. They can be rewound but it would be expensive.
I`m keeping my fingers crossed for you, let us know how you get on.

Bob

TGC61

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Re: Recommissioning a Lister ST2 with Brush Generator
« Reply #5 on: October 09, 2022, 06:55:51 AM »
Thanks Bob - that is very helpful! Could you possibly point me in the direction of the replacement rectifier? I have the engineer friend coming today to do some more investigation and hopefully I will have good news. I'm amazed that all those parts can get so grubby and still work but here's hoping!

I will send you some images of the various electrical sections for comments. The box on top of the alternator was basically full of dust and spider web but looks clean now. The rubber feet seem to have most degraded and the box itself needs a rust treat and new paint. The startomatic control box is very fresh indeed internally.

Thanks again

Tom


ajaffa1

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Re: Recommissioning a Lister ST2 with Brush Generator
« Reply #7 on: October 09, 2022, 08:01:05 AM »
Hi Tom, yes that bridge rectifier should be fine but it will need to be mounted on an aluminium heatsink to keep it cool.

I hope your engineer mate finds nothing nasty.

Bob

TGC61

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Re: Recommissioning a Lister ST2 with Brush Generator
« Reply #8 on: October 09, 2022, 03:31:40 PM »
So we seem to have power! Having checked everything that could be checked and throughly cleaning the brushes we started the engine and it was producing 225 volts and 17 amps. When we connected it via a lead to a heat gun and it successfully powered that so next was to throw the switch to the house and see how it got on with that. Again all good but some of the lights in the house were flickering and when we turned on the compressor that we were using to clean the alternator it produced a certain amount of sparking from the brushes. So we gave the slip rings a light skim with wet and dry and that seemed to cure it. The voltage was still slightly fluctuating between 225 and 228. there was a lot of grease around the end of the alternator where it meets the housing and that seemed to have leaked onto the slip rings so we cleaned them thoroughly with a dry cleaning type fluid and now the voltage seems to have settled down and all house electrics working without flickering.

Regarding the startomatic element. When you try to start the engine with the manual start button everything clicks and whirs and the engine starts but then the little pin to the left of the engine rotates back again and the engine stops. However, if you leave it in the auto position and then throw the switch from Mains power to 'MAG' as written on the switch? It starts and runs perfectly. To take this further if you throw the main power switch that disconnects everything from the mains ie to simulate a power cut, nothing happens at a ll. Does this mean that this set up was never fully startomatic? I can see the logic of this as it might start the machine when you were away and just drain the tank.

Anyway. We have now removed the fuel lines and making new copper ones and thoroughly cleaning the fuel tank. Changing the oil and replacing filters and looking for some new feet for the top box as the rubber one are all but gone. And of course replacing the selenium rectifier.

Overall though a very successful day!
« Last Edit: October 09, 2022, 03:39:35 PM by TGC61 »

ajaffa1

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Re: Recommissioning a Lister ST2 with Brush Generator
« Reply #9 on: October 09, 2022, 09:45:53 PM »
Well done Tom, another Lister brought back to life!  :)
It does look like it was never installed as a fully startomatic. I don`t think the 24volt sensing circuit that detects a demand for power would be compatible with modern electronic equipment. I found the best way to overcome this was to wire a single 100watt light bulb, with a switch, across the house feed from the generator. when the light bulb switch was turned on the generator would sense the load and fire up. I would then throw the cross over switch to power the house. Please have someone check the house wiring, you don`t want to be back feeding the local grid during a blackout. You could electrocute the lineman trying to fix the problem!
I see in your photo that there are still two selenium rectifiers in your control panel, these should also be replaced with modern silicon diodes.
I note the piece of fuse wire screwed to the top of the old blade fuse, not ideal. I replaced this with a modern 30 amp circuit breaker.
Next time you have it running check the battery voltage, I found that mine was overcharging the batteries and reducing their life expectancy. Eventually I disconnected the charging circuit and ran two mains powered trickle chargers, my last set of batteries were still going strong after 6 years.
Once again well done,

Bob

TGC61

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Re: Recommissioning a Lister ST2 with Brush Generator
« Reply #10 on: October 10, 2022, 05:55:09 AM »
Thanks Bob - all noted! I will certainly get all the bits changed. I have to buy a couple of batteries as the old ones will not take a charge unfortunately but not a surprise! Will any standard car batteries work for this? I'm attaching a picture of the unit that's attached to the battery wiring.

Cleaned out the fuel tank yesterday. It was full of very serviceable fuel but there was about a half inch of grunge at the bottom so well worth the effort. All being well I can now get on with cosmetically improving the set as it sits in the car port here and would be nice if it looked a bit less derelict!

ajaffa1

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Re: Recommissioning a Lister ST2 with Brush Generator
« Reply #11 on: October 10, 2022, 07:55:57 AM »
Hi Tom, yes any 2 car batteries in series will be fine, I paid about forty pound (80Australian dollars) each for my last set. Check out that charger to make sure it isn`t overcharging them and make sure the original lister charging circuit has been disconnected, it is connected to the large variable rheostat in the top box.
Looking forward to some shiny pics once you have it all done.

Bob

TGC61

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Re: Recommissioning a Lister ST2 with Brush Generator
« Reply #12 on: October 10, 2022, 09:47:53 AM »
Thanks Bob - I will get a pair this week and check the charging that unit's producing. Regarding smartening it up a bit. The paint is very patchy but I'm not planning to strip it right down when it doesn't need it mechanically. What is the best way to tackle paintwork on this would you say from your experience? Obviously very tricky to reach certain areas

Tom
« Last Edit: October 10, 2022, 05:27:02 PM by TGC61 »

ajaffa1

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Re: Recommissioning a Lister ST2 with Brush Generator
« Reply #13 on: October 10, 2022, 10:01:38 PM »
Hi Tom, I understand your lack of enthusiasm for a total rebuild of a fully functioning machine. There are a couple of things I would recommend stripping down.  This engine is air cooled, there is a large fan in the flywheel housing, that blows cooling air around the two cylinders. There is some steel sheet ducting from the top of the flywheel housing around the back of the engine, I would remove this and ensure the cooling vanes on the cylinders are clear of dust, cobwebs, mouse nests and etc. Also clear the small hole at the bottom of the flywheel housing. The crankshaft seal behind the flywheel is made of felt, not neoprene and can leak a small amount of oil, better if it runs out the bottom of the housing than gets blown up through the engine cooling system.

Paint is a difficult question, new paint will not stick to oil or grease  so it will need to be degreased and then washed and dried. I have used a low pressure pressure washer for this in the past, just avoid filling the exhaust and air intake with water. This should remove most of the loose paint grease and etc. The red oxide primer is very resilient and is unlikely to wash or flake off, so you should be able to just apply a couple of coats of mid Brunswick green top coat. This can be sprayed or hand painted, remember to mask up areas you don`t want to paint. I hand painted mine, I found that small artists brushes were very good for getting into awkward places.

Bob

TGC61

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Re: Recommissioning a Lister ST2 with Brush Generator
« Reply #14 on: October 11, 2022, 06:53:56 AM »
Thanks Bob

I spoke with a local company "real diesels" who do superb reconditioned Listers. They only do the paintwork as part of a full rebuild and as the engines had so little use it seems best to leave well alone and put any budget into the alternator if needed. I will do the best I can with the method you prescribe.

One small point - do you have any recommendations for fresh oil?