Lister SR2 Genset Frequency Matter

[drawshave]

Hello, I haven't posted for awhile, but HAVE been reading..I just aquired a Lister Sr2 generator. It's running good now, had lots of outlets for 230v. I want 120 too, so took apart the outlet box and there are 4 wires from the generator (and there are 4 brushes). I adjusted the engine speed slightly to get 60HZ on the one leg, and at that speed it was reading about 127 volts. The other leg was the same voltage (approx), but only 23-24HZ. What gives? I am tickled with this thing, it starts my radial saw without a grunt, even. Can anyone help? I expect to use this as my off-grid gen. There are no tags or markings on the generator end, what kind is it? I expect there is something I'm overlooking, I'm not much on the electrical end of things. But this thing appears to be simplicity itself.

[ListerDiesel]

Generally speaking, what you get from one phase (leg) should be the same frequency from any of the others.

What are you using to check frequency with?

Engine is serial 4297, Type SR, number of cylinders 2, reverse rotation and made in 1969. probably one of the Monarch sets.

Peter

[drawshave]

Yes, it is a Monarch set. I used a Kill-a-watt meter, the plug-into-the-outlet kind.(all I have). Thanks, Jim

[drawshave]

Does anyone else have an idea about this frequency aberration? I have read that getting the frequency at 59.9 or 60 hz is more important than the voltage being a little high. True?

As an interesting note (to me at least), I ran the generator today with a 10 amp load, and got fuel consumption of slightly over a quart an hour, call it 3.5 hrs. on a gallon of fuel. According to the specs, it uses .55 to .60 gal/hr with a full load. My gasoline gen. uses more fuel with no load than the Lister with full load. Jim

[BTPost]

Here is a Gent that is experiencing the WONDERS of Diesel Engine Ownership... and they don't have Spark Plugs, or carburetors, either....

[ListerDiesel]

Jim:

The frequency will affect the speed of synchronous devices such as induction motors and clocks with an induction motor inside.

The voltage will affect the life and brightness of filament bulbs. Computer power supplies use switch-mode technology and they won't mind fairly wide swings of both voltage and frequency.

You should be able to get it within 1hz or so, that is close enough, and the voltage should be within 5V at full load, under not over.

Check both off-load and on-load voltages to see if the regulator is working.

Peter

[BTPost]

[Quote] Does anyone else have an idea about this frequency aberration? I have read that getting the frequency at 59.9 or 60 Hz is more important than the voltage being a little high. True? [Quote]

I wouldn't worry to much about your Frequency Aberration, if your getting a good 60 Hz reading on one Leg, and good voltage readings on BOTH Legs.
Just set up the governor using the Good Frequency reading for a Hz or two above 60 Hz unloaded, and then check to be sure that you don't drop below 58 Hz at 100% of Rated Load. If by chance your governor is better than most, and yours has less spread unloaded to loaded, split the difference with 60 Hz as the center. Once that is done then go back and look at the AC Voltage, unloaded to 100% Rated Load. Should be within +/- 10% with 120 Vac as the center. Some genends really don't have a Full Blown AVR, and use Capacitor, or Buck/Boost Transformer Regulation, which will not have as good of Voltage Regulation, as a Good AVR design. You get what you pay for in this regard.

[gpkull]

i do say. freq in a gen is a direct ratio of rpms and # of poles. if you have a 240/120 gen head and running 2 120 volt in parellel the freq will be the same on both windings. unless you have some magic trick or devise it aint happenin. (different freqs that is). your kill a watt will however misslead you as it has me. when in freq mode unloaded (gen purring away with no load) the freq will bounce al;l over the place. try the same load on both legs and see if that wont answer your question. had one drive me only1/2 nuts till i got it

also BT great coverage on the loose ends that my pea brain just wont retain.

he has indeed caught the compression ignition bug. it is a good thing. there are more things worse than a kid screaming and a genny is way up there

[drawshave]

Yes, I agree. I actually thought it was running too slow, by the sound and looking at the crankshaft. What joy finding the engine was running a little fast. I have been lusting after one of the SLOW speed single cyl. Listers, ie water cooled, and big flywheels. But the oppurtunity for a reasonably priced one didn't happen, and this did.
It looks like it has a board over the brushes area, with what looks like little capacitors. I will do some more testing per the good advice you all gave.
I plan to mount a GM alternator via belt to the crankshaft. I think I might have to trim the hand crank end back a bit for pulley clearance, but should work OK. I ordered a pulley with 1.5 inch hub yesterday.Then I can charge my deep cycles for use with the inverter.
I can't find much on the Monarch Co., was it Canada based?, and what did they add to the engine? I assume the genhead, valve covers, fuel tank, what else? are they still in business? Is there a way to build a cheap Murphy shutoff type system? thanks for the advice... Jim

[drawshave]

In regards to this unit, does anyone know what the amperage rating would be? I am going to mount a box with breakers and outlets, and what size breakers would be appropriate? thanks

[Joseph]

Monarch was part of Consolidated Diesel Electric a US based company because they were made for the military they were required to contain a certain percentage of US made parts. As such they ordered the basic engine from lister and then added the US made parts. From what I have found that is the rocker covers,fuel system, gen and controls as well as a non standard flywheel and bellhousing atleast that is what I was told.

[moteurdelco]

the sr2 lister can drive up to 7500 watts;it is 30 amps at 240 volts.
the gend end looks like a pincor .their 15 kw pto units were tranfo regulated.

[Joseph]

Originally Posted by moteurdelco

the sr2 lister can drive up to 7500 watts;it is 30 amps at 240 volts.
the gend end looks like a pincor .their 15 kw pto units were tranfo regulated.

If the rule of thumb is 2 horse power per KW and the engine is only 12HP how can it deliver 7.5KW

[BTPost]

That is a conservative "Rule of Thumb" and most Gensets that have Lister Engines will put out REAL HoresPower at their Rated RPM, as opposed to those Chinese HorsePower, that only show up on the Data Sheet.

The actual Conversion is 1 HP = .746 KW... So if you have 12 HP * .746 = 8.94 Kw

[Chuck Moss]

Aloha Gents,

HP to KW factor correct, assuming 100% efficiency of the generator in converting the mechanical HP to KW which is never that good. Near as I can tell, 80% generator efficiency is typical for these "small" generators.

So, perhaps we should 8.94 * .8 = 7.2 ?

Facts and data relative to the 80% efficiency of mechanical to electrical would be welcome.

Chuck

[Power]

So, perhaps we should 8.94 * .8 = 7.2 ?
Yes.