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Author Topic: FR1 generator project  (Read 13155 times)

Reg Burn

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FR1 generator project
« on: June 26, 2015, 05:21:17 PM »
Good afternoon guys

A new engine has found its way into my garage, not sure how got there - that's what I'm telling the missis. It's a belting project that will keep me busy for some time. Sorry ListardJP2!

It's a Lister FR1 which is coupled to a 3 KVA AC alternator (and a small shunt alternator that I assume to act as an exciter) then a separate DC dynamo of about 100 volts. The generators are made by Electric Engineering Company in Wolverhampton and are massive for their output, solid British engineering.

It arrived yesterday, turning over with no compression. After checking the valve seats and piston clearance I noticed the injector clamp stud was not fully screwed in which prevented the injector sealing with the base of its sleeve. Tightened this up and now have reasonable compression considering its age. Fuel pump sticky as usual, so removed it, disassembled, cleaned and reassembled. I'll be ready to crank it up early next week.

I will at some stage be asking some questions about the generator units because I am delving into an area I don't fully understand and a mistake with 230 volts AC and/or 100 volts DC would hurt. Any advice at any time would be great, there is not much information about these things.

The engine differs from my FR2's and FR4 (apart from the obvious) because it has a unit bolted over the governor, and cross referencing the part numbers with the Instruction Book, appears to be a 'Fuel Control Mechanism (Trip type)'. The normal weighted governor, which is present as well, will regulate the engine speed by controlling the fuel. Does any one know what this does that is different from the normal governor? This one has a couple of wires going nowhere which may operate a trip of some kind. Initially I will run the engine with this unit off but if there is any info out there, thanks in advance.

Best, Reg


listard-jp2

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Re: FR1 generator project
« Reply #1 on: June 26, 2015, 08:03:59 PM »


Yes I know the generating set you mean, I had a look at this generating set some time ago when I was offered it, and passed on it.

http://www.ebay.co.uk/itm/Lister-FR1-generator-spares-or-repairs-/191601154519?pt=LH_DefaultDomain_3&hash=item2c9c5199d7

You should take a VERY CLOSE look at the division between the water jacket and fuel filter.

I know of where there may still be a control cabinet that would be correct for this generating set if you are interested.

It is certainly a lot of cast iron for 3KVA

Reg Burn

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Re: FR1 generator project
« Reply #2 on: June 26, 2015, 09:07:34 PM »
Oh dear, is there a crack?
I haven't checked yet.
What I did on another engine with a crack was put a fat gasket under the fuel filter lid and simply made the fuel filter cavity part of the water system.

I would be interested in the control cabinet. I don't know a great deal about generating electricity apart from coupling an old SOM alternator and tapping off the power from the control box. What does the alternator produce? I thought it would produce AC that would fluctuate with the engine speed and the control cabinet regulates that power using some kind of transformer.

Reg

starfire

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Re: FR1 generator project
« Reply #3 on: June 27, 2015, 04:56:58 PM »
just a note on wiring up unknown mains alternators.
With AC alternators, the frequency is governed by the engine RPM, this is held reasonably constant by governor action. Any deviation of around +_ 10 cycles is niether here or there, unless you are hoping to run a mains frequency derived electric clock... hardly likely.
The voltage on the other hand is a function of both RPM and load. With reasonably constant RPM already mentioned, the bugbear is loading. Prior to electronic AVR systems, clever ways were developed to hold the voltage at a reasonably constant value, keeping in mind an alternator load fluctuation can be almost 100 percent, ie, no load to full load. One common method was to use what is called a saturating inductor, basically a current transformer  placed in series with the output current. As the current increased, the magnetic field would increase as well, the induced secondary voltage  would then be added to, or subtracted from the nominal feild current, depending on loading. These work fine, but can cause a voltage overshoot, or spike as when say an appliance such as a refrigerator or air compressor switches off . This is the most common form of regulation in older machines. Machines having a seperate exciter to supply the field current, usually have some form of electronic stabilisation to vary the DC current into the fields. Earlier excited units used tertiary windings on the stator to "bend" or shift the internal magnetic field to vary the efficiency of the main alternator, in effect advancing or retarding the magnetic signature. The more heavily loaded an alternator is, the more constant will be its output voltage. Many alternators are internally wired to supply both 120 or 240 volts, hard wired  jumpers are used to do the selection. Field voltage varies considerably between models, I have seen anything from 6 volts to 150 volts used to excite the main alternator, this is always DC, and is identified by having a segmented commutator as opposed to the normal slip rings.... most early exciters are a seperate unit, although they can be integral to the main machine. Exciters depend on residual magnetism to initiate the generation of power, as do all other types.  One other method used to regulate voltage is the "phase shift" method, whereby a capacitor is used to create a lag between the field and main windings, here the field is actually fed with pulsating DC. As with a inductive reactor, a capcitance also has reactance, but in the reverse sense, working identically to  capacitor start  electric motor.
To wire up an alternator from scratch, with no diagram can be a nightmare, but if tackled in a logical manner, all those same coloured wires can be identified quite easily with a simple continuety test. A car or motorbike battery can be used initially to excite the feilds to further identify what winding does what, and with the engine running, the DC exciter connections can also be identified. Take your time, and be safe when working with these, when they bite, they bite hard.
« Last Edit: June 27, 2015, 05:05:37 PM by starfire »

listard-jp2

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Re: FR1 generator project
« Reply #4 on: June 27, 2015, 05:55:00 PM »
What I did on another engine with a crack was put a fat gasket under the fuel filter lid and simply made the fuel filter cavity part of the water system.
Thats exactly what you will need to do on this engine. Then you will need to find a suitable home for a remotely mounted fuel filter.

The disadvantage of this solution is that the filtered fuel can no longer be preheated, and you will have drill holes in parts of the engine (where there were previously none) to get the filtered fuel supply to the fuel pump

I would be interested in the control cabinet. What does the alternator produce?

I will make an enquiry on the cabinet and get back to you, the alternator will produce 240VAC single phase.

The set that you bought would have originally come from a small GPO telephone exchange, and as a result it has all sorts of interesting features: immersion heater element in the bottom of the radiator, centrifugal electrical switch on the engine, and a 100 VDC Dynamo which can also be used as an electric motor to start the engine

It would be easier for me if you were to PM me some off forum contact details.

listard-jp2

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Re: FR1 generator project
« Reply #5 on: June 30, 2015, 06:29:35 PM »
How are you progressing with the FR1 generating set, as I now have some photos of the control panel, and contact details of the owner.

Reg Burn

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Re: FR1 generator project
« Reply #6 on: June 30, 2015, 11:57:45 PM »
Been busy.

I took the top off the fuel filter and I could see what appeared to be a crack (in the usual place). I filled the fuel filter cavity with water to see if it would leak through this crack but after 24 hours the water level had not dropped. Then I drained this water out and filled the radiator. Water dripped from the water pump (as expected) and from a rubber pipe connecting the top and bottom of the radiator and the water pump. I replaced this pipe but will put up with the water pump leak until later. Water did not seep into the fuel filter cavity. I still suspect there is a problem and will address it in the future with some kind of filler.

The fuel pump was stuck and needed some coaxing to get it free. It has been fully dismantled and is now back together. The injector didn't 'creak' due to the valve being glued in the nozzle. By clamping the valve in the vice and gently turning the nozzle I have freed this part and it works a dream making a clear creak and the spray looks good too. The compression changeover valve appeared to have a poor seal so I shot it out (unbolt the changeover lever bracket, crank the engine and flick the decompression lever and the unit fires at great velocity across the workshop) thankfully it hit a padded fishing mat! In its history the return spring circlip has been lost or damaged and replaced with a blob of brazed weld, thankfully I have a replacement valve that I will prepare for future use.

But I still could not start the engine, there was significant air leaking down the side of the piston. Removed and inspected the piston. The rings were in good condition but there was a huge chunk out of the ridge between two ring-grooves about an inch and a half long. Looking like a segment of piston ring, the piece was still there. So that has been replaced with a good used piston from the shed, the engine is back together and I will attempt a start tomorrow (Wednesday).

During this operation I unfortunately dropped a cap nut into the sump which forced me to scrape out the thick cr*p in the sump.

The part we thought was a centrifugal switch is in fact a Fuel Control Mechanism (Trip Type) - see page 97 of the operators manual. The manual has no illustration but the part numbers are the same. I have no idea how this works, it appears to require some electrical pulse to activate a copper cone across two terminals. Any advice would be handy, I also need advice on the generator side of things because here I have no idea what I am doing.

I am very interested in the control panel but will I know how to fit the thing. I will send you a PM with my contact details.

Best regards, Reg



listard-jp2

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Re: FR1 generator project
« Reply #7 on: July 01, 2015, 07:42:45 AM »
I filled the fuel filter cavity with water to see if it would leak through this crack but after 24 hours the water level had not dropped.

Give it time and it will leak, as rust has quite possibly sealed up the crack by now, and formed a temporary seal.

I still could not start the engine, there was significant air leaking down the side of the piston. Removed and inspected the piston. The rings were in good condition but there was a huge chunk out of the ridge between two ring-grooves about an inch and a half long. Looking like a segment of piston ring, the piece was still there.

That is usually what happens when you try and start an engine with large quantitys of easy start. When I looked this engine over a while back I also noticed the loss of compression pressure past the piston. Then, when introducing a small amount of oil into the cylinder via the injector hole didnt improve the compression significantly. This taken together with the frost damage made my mind up to pass on this generator set.  

Did the piston damage have any detrimental effect on the Chrome plating?

In light of what you have found so far I think I dodged a bullet on this occasion  ;D


I also need advice on the generator side of things because here I have no idea what I am doing.

I am very interested in the control panel but will I know how to fit the thing.


When I looked at buying this generating set, that thought had also occured to me, hence I sought out a contact on another forum who seemed knowledgable on these generating sets, I will also pass those details onto you.
« Last Edit: July 01, 2015, 07:57:21 AM by listard-jp2 »

listard-jp2

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Re: FR1 generator project
« Reply #8 on: July 04, 2015, 05:08:50 PM »
Hi Reg,
Got your PM! and will be replying to your email address in the near future.
Regards,
Listard.

Reg Burn

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Re: FR1 generator project
« Reply #9 on: July 06, 2015, 12:34:50 PM »
Hi startfire

Thanks for your helpful reply, it has started the ball rolling, here are my results so far.

The generating unit was built by ECC, Wolverhampton, UK after 1936. It comprises a DC Shunt dynamo (4.38 amp, 35 volts) which is connected to the field coils in the AC alternator (13.55 amp, 230 volt). There is also an independent DC dynamo (20 amps, 30 volts).

I presume the shunt should excite the AC generator field coils.

I checked the resistance in the coils and armature and they all seem good. When the engine is running the Shunt only produces about half a volt, the AC alternator about 13 volts and the DC dynamo about 1.7 volts. These low outputs indicated there was little or no residual excitation voltage. I attempt to 'flash the fields' but this didn't change anything, then I tested the capacitors which all failed.

The Capacitors are Dubilier, 20PC, Micadon 2250 D.C.T., Type 680, 01µF. Will modern equivalents do the job and how can I work out which to buy?

If I can get this beast generating I will regulate it with a modern transformer as you advised and as used on Start-o-matics. Only then will I consider using a matching period control box - but that will open a whole new rats nest.

Reg

mike90045

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Re: FR1 generator project
« Reply #10 on: July 07, 2015, 01:53:44 AM »
Quote
The Capacitors are Dubilier, 20PC, Micadon 2250 D.C.T., Type 680, 01µF. Will modern equivalents do the job and how can I work out which to buy?

Those are pretty small caps, and most any modern cap with a high enough voltage rating would work.   I don't see volts listed in the spec ?

Are they "square" shaped with a lead sticking out from either end?   Like half a Domino ?   Those generally last forever (mica).
  If they are round like rolled paper, or oil-filled, they can be expected to eventually fail and would need to be replaced every 20 years or so.

Reg Burn

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Re: FR1 generator project
« Reply #11 on: July 07, 2015, 10:18:04 AM »
Hi Mike and thanks for your reply

The capacitors are about the same size as a domino, brown in colour, with lead connectors at each end and with two small screw holes on diagonal opposing corners. The only markings on the caps are:

Dubilier
20PC
Micadon
2250 D.C.T.
Type 680,
CAP
01µF

I have found a Dubilier catalogue from 1951 that shows the Type 680 capacitor. There were two versions, 750 VDC and 2000 VDC. I presume the '01µF' to mean 0.01µF which means these fall into the 750 VDC group. If you copy this into your browser you will get a link to the catalogue: (Dubilier_-_Concerning_Dubilier_Capacitors)

Each of the three units: (the shunt, the AC alternator and the DC dynamo) has a pair of these caps, there are six in total. I have performed various multimeter tests (ohms and voltage drops) and they all fail but they all show the same capacitance. It is strange they all fail maybe I am not performing the tests correctly.

I have had advice from a user at 'sparksandarcs' who says because of the small voltage readings I do have residual. Where is the residual stored, the field windings or the capacitors? The OP also suggested I clean up the commutators and slip rings. I'll give that a go.

If that fails I'll be back searching for capacitors. There seem many different types with subtle differences and my chief concerns are damaging the internals of the generators and paying for the wrong capacitors.

I will try to post some pictures.
Reg

Reg Burn

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Re: FR1 generator project
« Reply #12 on: July 07, 2015, 10:09:03 PM »
Hi Mike90045




I have learned to post images on forums. This is the capacitor. I have run the generator today with these all removed and the results have been the same. So I deduce they are not required to store residual exciting voltage but are probably there as a suppressor for TV and other similar electronic devices.

It appears I have had open circuits which I plan to close and perform new tests.

Best regards, REG

mike90045

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Re: FR1 generator project
« Reply #13 on: July 07, 2015, 11:26:32 PM »
mica capacitors are VERY reliable critters, and short of a bolt of lightning hitting them, they are pretty reliable.

The values they are, are so small, I'd expect to see them in a noise reduction circuit on brushes.  They are too small to store power for harmonic windings, by my estimation.

How do you have a hand held meter that tests them ?  A DC test for shorts, should show infinite impedance.

millman56

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Re: FR1 generator project
« Reply #14 on: July 09, 2015, 04:35:42 AM »
They cylindrical type crop up regularly on older alternators with a DC excitation/start winding and as Mike says, it appears  they are to reduce arcing interferance from the commutator and have no other purpose I can see.    The generators work fine without them but an oscilloscope reading may show up exactly what they do.      Mark.