30 amp alternator

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Geochurchi
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30 amp alternator

Post by Geochurchi »

Good morning, anyone know how the alternator is connected to the front of a B&S V twin engine on the Titan train locomotive?
Thanks
If it ain’t broken keep working on it until it is .
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Steggy
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Re: 30 amp alternator

Post by Steggy »

Geochurchi wrote: ↑Mon Feb 12, 2024 8:33 am Good morning, anyone know how the alternator is connected to the front of a B&S V twin engine on the Titan train locomotive?
Thanks

You referring to the electrical connections, or the way in which the V-twin drives the alternator?
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Geochurchi
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Re: 30 amp alternator

Post by Geochurchi »

The way the alternator is physically connected to the V twin.
Thanks
If it ain’t broken keep working on it until it is .
Geo πŸ‡ΊπŸ‡Έ
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Steggy
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Re: 30 amp alternator

Post by Steggy »

Geochurchi wrote: ↑Wed Feb 14, 2024 7:28 am The way the alternator is physically connected to the V twin.
Thanks

The alternator is driven from a stub PTO shaft that is bolted to the face of the engine’s flywheel.Β  A jaw-type β€œflexible” coupling (aka β€œLovejoy coupling”) is used to make the connection.Β  I don’t recall precisely how the coupling is attached to the alternator itself.

The stub PTO shaft is sold as part of a Briggs kit, which, according to my records, is P/N 841580.Β  The shaft itself is one inch diameter, with a 1/4" Γ— 1/8" deep keyseat.Β  There is also a modified blower screen that goes with it, for which I don’t have a part number handy.Β  Incidentally, Briggs service notes state that the V-twin should not be run without the blower screen in place.Β  The reason has to do with preventing turbulence that will cause a loss of cooling airflow at higher RPM.

The above arrangement obviously spins the alternator at crankshaft speed, which is unfortunate.Β  In the best speed range in which to operate the V-twin under load, 1600-2000 RPM, the alternator will not be spinning fast enough to produce its rated output.Β  In my F-unit, I wanted the alternator to produce useful output with the prime mover idling at 1000 RPM (which is a much slower idle than stock).Β  For that reason, I fashioned a timing belt drive to spin the alternator at 1.82 times crankshaft speed:

Alternator Drive
Alternator Drive
accessory_drive01.jpg (285.92 KiB) Viewed 246 times

The alternator will produce its rated output with the V-twin spinning at about 1600 RPM.
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Music isn’t at all difficult.Β  All you gotta do is play the right notes at the right time!Β  :D
Geochurchi
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Re: 30 amp alternator

Post by Geochurchi »

Thanks, from what I remember seeing, the alternator was connected directly to the shaft with a Love Joy coupling.
If it ain’t broken keep working on it until it is .
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OTmachine
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Re: 30 amp alternator

Post by OTmachine »

If you are using a Delco-Remy as shown in @Steggy’s post, (looks like a 60A), you can get a regulator that requires low rpm to excite. Possibly there is an adjustable external regulator that you could use. I used to work on forklifts with low rpm threshold motors and had to modify at times to keep batteries charged, (especially when customers would add on external computers). I had a Good alternator / generator repair shop to implement the changes required.
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Re: 30 amp alternator

Post by Steggy »

OTmachine wrote: ↑Fri Feb 16, 2024 9:57 amIf you are using a Delco-Remy as shown in @Steggy’s post, (looks like a 60A), you can get a regulator that requires low rpm to excite.

Actually, it’s a 30 amp alternator, modified to reduce its maximum output to 25 amps, with the regulated, light-load voltage set to ~13.5 maximum.Β  The reduced-voltage modification makes the alternator compatible with sealed lead-acid batteries of the type used in uninterruptible power sources.
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Music isn’t at all difficult.Β  All you gotta do is play the right notes at the right time!Β  :D
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