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#119029 11/28/04 09:26 AM
Joined: Dec 2001
Posts: 2,498
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Member
I've seen a basement addition. The vasement of an apartment house (ca. 1900, pretty damp brick basement) is split up into cubicles for the tenants. Originally the cubicles (actually small rooms with more or less solid brick walls) didn't have any wiring, just the hallways were wired with ancient lead cable. At soem point a tenant decided to tap into the libne and get power to his cubicle. He put in a wooden junction box just like the one in the picture, just without the terminal strips (just twisted and taped connections) and a sheet metal cover.

#119030 11/29/04 11:31 AM
Joined: Mar 2002
Posts: 360
T
Member
Hi guys,
I recognize those terminals! [Linked Image]

Those terminal blocks are railroad equipment. How many of them do you want. I have lots of them. Normally they come with Railroad lightning arrestors or other equipment. The hardware is 1/4-24. Normally 1/4 inch TPI is 20 or 28.

They are readily available, from Saftran, p/n 023612-1X.

Any of the big cabinets next to any crossing will be full of these things. Usually they are mounted under a part that would need to be replaced on a frequent basis, such as a lightning arrestors, or resistors. When you work with those really big parallel ground rods, you need to take lightning into consideration on any installation.

Looking at the picture again, it looks like the wire going to the barn might be railroad signal cabinet wire. Good stuff, most of it is rated at 1000v.
TW

edit to add last paragraph.

[This message has been edited by Trainwire (edited 11-29-2004).]

#119031 11/29/04 11:33 AM
Joined: Aug 2002
Posts: 1,691
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Member
How about one or two? I got some splices I need to make in my bathroom... [Linked Image]

#119032 11/29/04 05:24 PM
Joined: Sep 2001
Posts: 806
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Member
What's the reasoning behind the 1/4"-24 threads? Just to be different, or to discourage theft, like the left-handed light bulbs used in the NYC subways?

#119033 11/30/04 07:08 AM
Joined: Mar 2002
Posts: 360
T
Member
[Linked Image]

Beats me why it's different. I will try and find out. It probably stems from the Railroads, like British Cars, do things their own way, and by God, nothing will change that. (I own, and work on,British Cars and run into the same sort of question). I am sure that at some point there was a long study on torque and holding power and electrical conductivity and speed of installation, or maybe the hardware salesman scored a big sale of some oddball stuff he had in the warehouse and once that was used up they had to stick with it.

I do know the nuts are a design that I have seen nowhere else, and are designed to be used in pairs, as in a second torqued down on the first as a safety. The nuts in the picture go on the bottom, under whatever is mounted to the junction, and then the special ones hold the device to the block.
I will see if I can get pictures. but I have said that before, so we will see if I can get that done.

TW

edited the spelling [Linked Image]

[This message has been edited by Trainwire (edited 11-30-2004).]

[This message has been edited by electure (edited 11-30-2004).]

#119034 11/30/04 02:12 PM
Joined: Jul 2004
Posts: 625
S
Member
I'll take a stab at a wild guess as to why. Since it's the railroad, it's quite possible that they started making this stuff before screw threads were standardized, and they keep doing it this way to be consistent with the installed base.

#119035 12/01/04 02:16 AM
Joined: Jul 2003
Posts: 394
B
Member
After looking closely at the box, I would not even give credit to a carpenter for that job. A carpenter would have made straight cuts on the sides of the box. Looks like a "Handyman Special" to me

#119036 12/04/04 09:12 PM
Joined: May 2002
Posts: 382
H
Member
Trainwire said...
Quote
Those terminal blocks are railroad equipment. How many of them do you want. I have lots of them. Normally they come with Railroad lightning arrestors or other equipment. The hardware is 1/4-24. Normally 1/4 inch TPI is 20 or 28.

That's a really strange thread! The British 1/4" fine thread (BSF) is 26 tpi. General Motors used to make a unique thread of 1/4" (GM said 6.35 mm) with a 1mm pitch (25.4 tpi).

#119037 12/06/04 05:59 PM
Joined: Dec 2004
Posts: 51
M
Member
they could have at least cleaned up too...lol

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