Lister Engine Forum
Lister Engines => Lister Based Generators => Topic started by: TGC61 on October 04, 2022, 09:09:21 AM
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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.
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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
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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
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Hi Bob - I've added a few more images of the front end for your comment
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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
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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
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Would it be something like this? https://www.ebay.co.uk/itm/403872715939?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=aspa0he4tqy&sssrc=2349624&ssuid=GwUzv5SETsi&var=&widget_ver=artemis&media=COPY
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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
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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!
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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
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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!
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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
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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
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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
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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?
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Hi Tom, I can`t advise you on a suitable grade of oil for use in the UK due to the temperature difference. My Lister had to be able to handle summer temperatures in excess of 50 centigrade and temperatures down to below zero in winter! I would however, advise you to drain the sump, leave the old oil filter in place and refill the sump with a diesel flushing oil. Run the motor for about 15 minutes until it reaches full operating temperature. Then drain out the flushing oil (do not throw it away it can be reused). Now replace the oil filter and fill with new oil.
There has been a lot of discussion about oil on the LEF, in my experience modern oils are a lot better than what was available 50 years ago. You can run a diesel car for three quarters of a million miles or more with regular oil changes. Any quality modern diesel engine oil should be better than anything they had back then.
Bob
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I've started on the tank as that needed to be cleaned internally and all the pipework changing.
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Hi Tom, I love that long run fuel tank, I have one that must be slightly earlier. Yours appears to have a couple of lugs for a sight gauge, mine has a float with a chain and a small pulley.
Bob
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Hi Bob - not sure of the capacity and it would be interesting to know how long it would run on a full tank. I'm replacing the sight tube as the old one was so dark as to be of no use. Re running the heavily corroded fuel Lins with copper tomorrow.
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Bob - I'm just in the process of changing that rectifier - I'm, not getting any power reading from it. What does it do excatly?
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Hi Tom, I am assuming that you are talking about the bridge rectifier in the gen head. There are two ways to generate electricity, one is to rotate a coil inside a magnet field. The second is to rotate a magnetic field inside a coil. In the Brush generator head a coil rotates within a magnetic field, with the generated electricity being collected from the two slip rings. These generators do not have permanent magnets, instead the magnetic field is created by passing a DC voltage through the set of 4 coils set around the inside of the generator housing. To do this it is necessary to rectify some of the generated AC voltage into DC voltage. The amount of DC voltage is determined by a large variable rheostat, also inside the gen head.
When the generator first spins up it starts to make electricity using residual magnetism left in the coils, as the ac voltage increases so does the rectified dc voltage which then sustains the magnetism in the electro magnets.
If you are having trouble with the new bridge rectifier, check that it`s orientation is correct, does you control panel have the wiring diagram in the back? It shows which way it should be wired. Check things with a multimeter.
Good luck,
Bob
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Thanks Bob - all done and thanks for the explanation about the workings. I hadn't realised that this type of generator did not have a permanent magnet. It's all very interesting.
I couldn't get anything out of it to check the charge but that was cured by putting it under load. Have attached the rectifier to the alloy body rather than the plastic grill.
Filled the tank properly and now with new copper lines so looking good - but.....there is now a tiny leak from the cleaned out fuel tank! So I've taken it off and will hopefully fix tgg he at with some tank sealant/repair products.
The batteries are on the trickle charger which seems to be working as it should.
Tom
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Well done Tom, another couple of steps closer to a perfect electric backup system.
I failed to answer your question about fuel consumption. The long run fuel tank you have is off a much earlier engine, probably a Lister CS.
A 6/1 CS will drive a 3KVA generator head and that tank would probably run it for about eight hour. I expect an ST2 would empty that tank in about 4 hours, depending on the load.
My ST2 SOM sat on a 300 Litre tank with a fuel lift pump and was good for a week or more. You might want to look for a larger tank if the electric supply is unreliable where you live.
Bob
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Ooh that sounds quite thirsty but I don't imagine we are looking at long outages. The engineer said it would run happily on the red kerosene we use for our heating boiler as long as you add about 1% volume oil. I'm not sure which oil, maybe two stroke? as that was designed to burn. That would make a significant difference to the running cost. I've attached a sheet provided by the installer that suggests that the standard 7 gallon tank ran for 14 hours. I've not checked the capacity of mine but it looks about that.
Tom
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Hi Tom, I`ve never tried running a diesel on kerosene but I have run kerosene heating boilers on diesel, so I guess it would work. I am thinking that Kero probably does not have the lubricating properties needed for the injector pump. I think two stroke oil would be ok.
I have a vintage Cooper engine that was designed to be started on petrol and then switched over to Kero, I didn`t find any excessive wear in valves or valve guides when I rebuilt it.
I wonder if you can get your hands on red diesel where you are? In the UK red diesel is sold to farmers and other essential industries at a much lower cost than the regular diesel you would buy at a fuel station. If you know any farmers they might be willing to sell you a few gallons.
Bob
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Hi Tom
I've been running a single cylinder Hatz all summer - about 700 hours, so far - with 20% filtered wvo. I discovered a bad attack of diesel bug last week end, the exhaust is a bit sooty, other than that, no problems.
Here's a good, concise brief on diesel bug
https://conidia.com/diesel-bug/#1576146601791-21bb4c02-2c33
The diesel bug contamination is almost certainly lack of attention to detail on my part, I just didn't give it a thought.....
The tank is in a lovely warm spot, next to the genny and veg oil is a great source of vitamins for the bug, it was almost bound to happen
I'm using red diesel / heating oil that had sat in an underground tank for a couple of years, I've now had a good clean out, new filter and am conditioning the fuel with a proprietary marine additive, I'm also looking more closely at what's in the ready use tank!
Somewhere on here, someone posted the results of a lubricity test in the US, I think, with with proprietary additives, and straight soya oil was as good or better than almost all of the competition and way cheaper.
I would say, as it's going to be a standby unit, add a little, 3 / 5% veg oil for lubrication and a fuel conditioner for protection.
A valve in the supply from the tank allowing to you to draw off any condensation at the bottom of the tank and check a small jam jar of fuel would be a worthwhile addition. as would a CAV 296 type filter with a glass (see through) sediment bowl.
Cheers
Stef
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Hi Stef, I`ve always been amazed that anything can live and grow in diesel. The same thing can happen with Kerosene. I remember having to clean out fuel tanks on the old Vulcan bombers. Confined space, toxic/ explosive environment and a pressure washer rubber suit and breathing apparatus. Lovely job! :laugh:
I`ve never had a problem with the diesel in Australia, I think the fuel emission rules are much less stringent so we are probably still using high sulfur fuels. Not so sure about our petrol, most countries removed the lead years ago because it is toxic and makes people stupid. Sadly they replaced it with benzine which is carcinogenic and makes people dead.
Bob
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Hi Stef
The last time the tank on mine was filled was in about 2003. The engine started on that fuel on the second turn. Lat time about twelve years ago. The tank was about half full and seems to be in good condition. It was obviously pre all the bio diesel additives etc etc. My only problem has been that there was a lot of sludge in the base, not sure what that was but it included a degree of corroded metal I think. Scraping the base of the tank revealed or created three or four pin holes which I've now filled with a full tank specific filler so hoping that will be that!
Tom