Lister Engine Forum

Lister Engines => Lister Based Generators => Topic started by: mikenash on August 12, 2020, 09:32:52 AM

Title: Two X big 105A alternators on the Lister CS
Post by: mikenash on August 12, 2020, 09:32:52 AM
Hi guys

I have a kinda hybrid CS6/8 here which I'd like to use to drive a couple of big Leece-Neville truck alternators to charge a bunch of 12V batteries (Yes, I know the 12V has many limitations, but it's a legacy system with a single large-ish 12V panel and three small 12V inverters and a bunch of batteries - so it's a "use what you got" system)

I forget what I paid for the two alternators - it might have been $40, or maybe $40 each?  They were new-old-stock, still in their boxes and packaging.

See pics?  I have the two of them on a base I can weld above one flywheel of the CS and put a flat-surfaced idler between and below them (adjustable in a couple planes) to use as a tensioner

The alternators have straight-blade fans (not fitted atm - I just have pulleys on for alignment purposes) and info on line says they don't care which direction they rotate at

I don't have a lot of info on them other than what I find on line; but I think their max RPMs are 8000.  So with a 600mm CS flywheel and a driven pulley around 70mm, even at 600 revs they're gonna be fine

I'd appreciate any experience-based thoughts on mounting/belts etc.  The grooves are for an SPB belt, but will drive just fine with a B

See pics?  How do you reckon I need to wire the buggers?

One pic shows a label with the + and the - and the instruction "observe polarity" and the = and - terminals on the casting at the other ends from those on the sign.  I suspect the label may be generic

I have no idea at all what the various other small terminals are for.  Possibly I can ignore most of them

The brief, generic guidelines on several Leece Neville installation blurbs say the installation needs a switch/key in the circuit and also a 6W bulb (so there's a wee current for excitation, perhaps?)

Expertise welcome :)
Title: Re: Two X big 105A alternators on the Lister CS
Post by: mike90045 on August 12, 2020, 09:41:51 PM
First, running significantly below spec RPM, will yield significantly lower output.  Which is good, because the fans will be moving significantly less cooling air.

The other terminals are for the regulator to connect to and energize the magnetic field .  As to which is which, the smaller terminals are the Field, which is often where the brushes are.  (low amps = low sparks on the brushes)
Title: Re: Two X big 105A alternators on the Lister CS
Post by: mikenash on August 13, 2020, 01:54:38 AM
Hi Mike

These are truck/bus units

Think of the diesel driving it as probably having a working RPM range circa 1200-3000

Even with a big gearing, I suspect that 8000RPM figure is the safe max for the units and their normal operating speed is probably truck RPMs X 2-ish.  I suspect their output is probably good at 5000 RPM

Guess we'll see.  Thanks for the thoughts
Title: Re: Two X big 105A alternators on the Lister CS
Post by: veggie on August 14, 2020, 06:44:18 PM
mikenash,

Most of the Leese alterators produce 90% of their output at 3000 rpm.
Between 3000 and 6000 there is not much increase.
Their output curve is quite flat past 3000.
If you are driving them at 3000 rpm or greater you will be getting near full output.

Assuming 100 amp alternators at 12 volts X 2 alternators = 2400 watts
Assuming 50% efficiency (The 2x rule of thumb) you will need 4800 watts (4.8kw) or 6.4 HP of engine power
That's full load for your engine.



Title: Re: Two X big 105A alternators on the Lister CS
Post by: mikenash on August 15, 2020, 07:28:31 AM
Yeah, I'd be happy with half, that.  If I was putting 2kW into my batteries there's be something wrong lol

I need enough battery and enough inverter to run an efficient fridge & a few LEDs at the same time - that's it really

Where I was at with the Leece Neville alternators is that I hope they will be robust and over-built

Yesterday I took them of the tacked-up mounting frame and welded it fully.  Now, of course, with the minor distortions of welding I'll have to "tweak" stuff to get the two pulleys perfectly in the same plane

No hurry,  The engine concerned is sitting 400Ks away with the barrel off and the piston is down here lol

One thing at a time . . .