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Start switch for our Porter diesel?
https://www.rypn.org/forums/viewtopic.php?f=1&t=25517		 Page 1 of 1
Author:  David H. Hamley [ Mon Jun 30, 2008 12:13 pm ]
Post subject:  Start switch for our Porter diesel?
Pennsylvania Trolley Museum owns and occasionally operates a nominal 45 ton Porter side-rod center-cab. We are having a problem with one engine start switch and wonder if anyone has a spare available. This loco, like a lot of the early models (8/42 in our case, b/n 7384) had the Westinghouse 189R5 main generator which lacks a start winding. So each Cummins diesel has a big 32V starter with Bendix drive to a ring gear on the flywheel. To ease the starter pinion into engagement, it uses a Leece-Neville type 132-SN two stage start switch. The first stage uses an 8V tap off the 32V battery bank to lightly goose the starter into engagement, then the second stage applies the full 32V to crank the engine. One of our two start switches is not making the first stage contact and thus the starter goes into the flywheel with too much vigor.

The switch has a circular face about 4" diameter with a large T-handle that rotates about 90 degrees from rest.

If anyone's got a spare or a UBG pull-out, we'd like to hear from you.
Author:  crij [ Mon Jun 30, 2008 2:30 pm ]
Post subject:  Re: Start switch for our Porter diesel?
Have you tried to see if the switch can be disassembled? You might just have dirty contacts in the switch or the relay it controls.

Copper-oxide and other forms of Smutz (dirt, grime, etc...) tends to make a nice insulator for low voltage DC.

Just a thought,

Rich C.
Author:  Al Stangenberger [ Mon Jun 30, 2008 5:51 pm ]
Post subject:  Re: Start switch for our Porter diesel?
crij wrote:
Copper-oxide and other forms of Smutz (dirt, grime, etc...) tends to make a nice insulator for low voltage DC.

Just a thought,

Rich C.


I'd second Rich's comment, and add bugs to the description of Smutz.

At WRM we are plagued with some sort of fly whose only function on earth seems to be to crawl into things, lay eggs, and die. One of our pieces of MOW equipment would not start because the starter switch was packed with their dead bodies which turned out to be good insulators.
Author:  Stephen Hussar [ Mon Jun 30, 2008 7:03 pm ]
Post subject:  Re: "Schmutz"
crij wrote:
...other forms of Smutz (dirt, grime, etc...) tends to make a nice insulator for low voltage DC.


Schmutz is such a funny word, and one my dad used to use, that I just had to look it up.

Turns out it's a real Yiddish word, and of course has a Wikipedia page devoted to it. Sorry Rich!!! http://en.wikipedia.org/wiki/Schmutz

Stephen Image
Author:  crij [ Tue Jul 01, 2008 1:50 pm ]
Post subject:  Re: "Schmutz"
Don't forget it's liquefied cousin known as Mung, which is usually found in the bottom of Diesel fuel tanks, crankcases of stored engines, bilges and other such collection points...

Sometimes the mung will evolve into schmutz if you are lucky... Sometimes I think that is how it gets into some of these places.

Rich C.
Author:  Dave [ Tue Jul 01, 2008 3:31 pm ]
Post subject:  Re: "Schmutz"
And graddoo, which gathers under crankcases and seals. Shayshit accumulates within flinging distance of the gears on the lineshaft.

dave
Author:  EDM [ Tue Jul 01, 2008 4:07 pm ]
Post subject:  Re: "Schmutz"
My favorite is "droil", made up of dirt, rust and oil-
Author:  Jim_Poston [ Tue Jul 01, 2008 11:27 pm ]
Post subject:  Re: "Schmutz"
"Glidge" - a term I learned just a few months ago - is the build-up of oil or grease, plus whatever dirt and Smutz it collects, on wheels and/or rails.

Early removal isn't too difficult, but left to accumulate, it has to be scraped off.
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