From what little I know about steam locomotives, the typical output of their generators was 32 volts. Does anyone know why such a voltage? It seems to be such an odd figure, but maybe certain priciples made it quite reasonable.

32v was a common voltage for battery systems. The common reason for 32 that I have heard is 16 lead acid cells in series make 32V.



pfdx@aol.com

> 32v was a common voltage for battery
> systems. The common reason for 32 that I
> have heard is 16 lead acid cells in series
> make 32V.

I think Paul hit it right on the head. That voltage was probally chosen because equipment was on the market for it. Most of the systems on the
farms before REA were 32 volts. I believe the Windchargers were 32 V also. Anyone remember that?
Jim


rrfanjim@mvn.net

> I think Paul hit it right on the head. That
> voltage was probally chosen because
> equipment was on the market for it. Most of
> the systems on the
> farms before REA were 32 volts. I believe
> the Windchargers were 32 V also. Anyone
> remember that?
> Jim

32Volt is also harmless if you accidently touch the cables. The Sunbeam turbos could bee ordered with 220 Volt as an option but that aint harmless as I know it. In the 271's cab-roof we have a totally open knife-switch - I dont think I dare touch that one in the dark in the cab if it swapped front/rear-headlight equipped whith 220V bulbs at 250 Watts.
Then the 32Volts system whith 250 Watts headligt can use common cablenr. - if you go for 12V you probbably need monstercables.
RaA

I was able to govern down the dynamo on GOAT to put out 24 volts and use tractor trailer lighting cheap off the shelf. Basic 12 or 14 gage wire is plenty enough at this voltage. It does hunt a bit but seems to work pretty well.

Dave

irondave@bellsouth.net

42 volts is the new standard for automotive applications. This is the highest voltage that is considered safe for humans to touch live wires and not get shocked.
The idea is to get the voltage up and the current down as much as possible. That means you can use smaller wires. I guess the loco designers were thinking in the same direction.

> From what little I know about steam
> locomotives, the typical output of their
> generators was 32 volts. Does anyone know
> why such a voltage? It seems to be such an
> odd figure, but maybe certain priciples made
> it quite reasonable.


soapysmith@bellsouth.net

> 32Volt is also harmless if you accidently
> touch the cables.

That is NOT necessarily true. While 32V is certainly safer than high voltage, an on-board system undoubtedly has more than enough current capacity to kill you. Even an ordinary 12V auto battery can be lethal under the right circumstances. If the weather is hot and you're sweating, your skin resistance drops to essentially zero. And just half an amp will probably be fatal.

Electricity can be just as deadly as the high-pressure steam boilers we're always talking about. Please be careful!

Randall Hicks (IRM)

> Electricity can be just as deadly as the
> high-pressure steam boilers we're always
> talking about. Please be careful!

> Randall Hicks (IRM)
That's true - but when touching the el. system in a steamlocomotive cab you ain't bare foot and that close to nude - or?? The part of your body that will react fatale on a current like 25 mA like the hart will not be in the circuit when you are dressed like firemen. The system onboard are not using the locomotive harness as return for the current on our locomotives. So to speak we say that the system is double insulated and that means 32V will only go over the skin on your hand/fingers. Be sure that 220V in the same situation will make you use som words we dont print here.
RaA

> 42 volts is the new standard for automotive
> applications. This is the highest voltage
> that is considered safe for humans to touch
> live wires and not get shocked.
> The idea is to get the voltage up and the
> current down as much as possible. That means
> you can use smaller wires. I guess the loco
> designers were thinking in the same
> direction.

Soapy; I drove a bakery route back in the 6 volt days. Did you ever try to start a cold stiff truck
at 2:30AM with a 6 volt system? It's the stuff for nightmares. Sure makes you appreciate the present day cars that start with the first turn of the key. Remembering the difference makes me interested to see the 42V jobs.
Jim


rrfanjim@mvn.net

Many thanks to all who posted responses to my question. This is a great board for finding even the detailed things!

Dick

> From what little I know about steam
> locomotives, the typical output of their
> generators was 32 volts. Does anyone know
> why such a voltage? It seems to be such an
> odd figure, but maybe certain priciples made
> it quite reasonable.
I aquired a daul Mar light off a Burlington scrapped steam engine. In order for it to work wright,It took every bit of 32volts to make it look like it was on the front of 5632.