Strain relief for electrical cord on old appliance?

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We have a very old appliance that has an electrical cord with no strain relief. The cord comes out of a square hole in the back. I have replaced the original cord with one that it more heavy-duty, but it still eventually shorts out. I'm going to go get a piece of stiff tubing about 1" long that will fit into the hole and run the cord through that. Is there a better idea?
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On 2/8/2011 1:25 AM, Prof Wonmug wrote:

There are commercially available strain reliefs which can be found on the Internet, depending on the cord size, the cut-out hole size, and the shape of the cut-out. See, as a single example:
http://www.parts-express.com/wizards/searchResults.cfm?srchExt T&srchCat5&utm_source=google&utm_medium=cpc&utm_termble%20strain%20reliefs&utm_campaign=G_Wire_Cables_Connectors_Terms_Broad_Plain&utm_groupble_Strain_Reliefs_Broad_Plain&9gtype=search&9gkwble%20strain%20reliefs&9gadp83292513.1&9gag"43855113
A Google search will yield many other options.
The approach you are using with tubing may work perfectly well. Another approach is to use some RTV / silicone caulk to fill the void, essentially building your own custom gasket. This would be particularly useful if the cut-out hole is a "D" shape or some other irregular cut-out.
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The early plugs were designed to be used with an "Underwriter's Knot" for strain relief.
Here is a link to a picture:
http://www.robertacory.com/RobertaCoryWebsite_files/Page412.htm
Handy to know...
/paul W3FIS
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On 2/8/2011 7:25 AM, deadgoose wrote:

I've seen reproduction electrical items from a company that copies old fixtures for interior decorating and the cost of the reproduction cloth covered cords is outrageous. Of course, I would expect the new reproduction wire to be superior to the old cloth and rubber but DANG!
TDD
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On 2/8/2011 8:33 AM, The Daring Dufas wrote:

I used to deal a lot with "Antique Electronics Supply" before they were bought out and went wild with their prices. (about 20? years ago) I did a search and this place looks very competitive with a great selection!
http://www.sundialwire.com/clothcoveredwire-1.aspx
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On 2/9/2011 3:27 PM, Tony Miklos wrote:

COOL! Thanks for that link. I made a new bookmark category "Electrical, Vintage & Reproduction" There are lots of folks who have old items they want repaired/restored who have the money to pay for it. :-)
I can't imagine the cost of wiring a theme restaurant or bar with knob and tube wiring. It would be a very interesting undertaking(no pun). :-)
TDD
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On 02/09/2011 09:25 PM, The Daring Dufas wrote:

I don't think that it would pass inspection today.
but I have found while looking for other old stuff that the old pushbutton light switches and switch plates are being reproduced... I remember those from my grandparents' house and always thought they were kind of cool.
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
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On 2/9/2011 8:29 PM, Nate Nagel wrote:

You don't think a local country club with a membership that includes a number of politicians couldn't get a waiver? Here's a link to vintage style switches, plates and vintage look dimmers.
http://preview.tinyurl.com/49nzlja
TDD
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The Daring Dufas wrote:

Not obvious where knob & tube came from in this thread.
Knob & tube is, specifically, concealed wiring. Wouldn't be any point in a theme restaurant if you can't see it. Could always install fake wiring. There is a restaurant here with a fake elevated train complete with sparks.
If it is in the open it is "open wiring on insulators". Use in the current code is limited to "industrial and agricultural establishments". Maybe if they serve agricultural products....
--
bud--

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On 2/10/2011 12:33 PM, bud-- wrote:

You are obviously not that familiar with knob and tube wiring. The earliest knob and tube wiring had parts that were exposed in areas like wall switches. It would be exposed in basements, attics and garages or anywhere the walls were not covered. I doubt most wiring was concealed during the rural electrification project in the 1930's. :-)
TDD
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The Daring Dufas wrote:

No plaster walls and ceilings in living areas in the 1930's? In two houses I lived in that had K&T most of the wiring was concealed or in an inaccessible attic One house did not have wiring when built.
But you were talking about new wiring to be done in a theme restaurant. The current NEC articles are: "394 Concealed knob-and-tube" "398 Open wiring on insulators" Same definitions in my oldest code book which is 1968. Open wiring on insulators can be similar to K&T.
I don't know, and you don't either, whether the exposed wiring you talk about was "open wiring on insulators" when installed.
--
bud--



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On 2/11/2011 1:05 PM, bud-- wrote:

Perhaps I'm thinking of the flat rectangular porcelain insulators that were often run on the surface of walls. Of course, other wiring was often concealed in decorative wood strips which had grooves in the back for the wire. I have seen knob supported wire run on the walls of workshops, garages and barns. Did all the old-time electricians follow the code back in the day? :-)
TDD
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The Daring Dufas wrote:

Interesting question.
My impression is that electricians were skilled tradesmen that followed whatever the applicable code was back in the early days. My impression is not based on much except seeing the installed results around here. Hard to imagine the labor involved in installing K&T.
Although the NEC goes back to the 1890's, I remember reading somewhere that there was a lot local variation and locally written codes long ago. A local code is a lot easier to do if the code is 50 pages instead of the roughly 800 large NEC pages now. There was supposed to have been a major push to get everyone standardized on the NEC. Might have been by the VA or FHA in the post WW2 housing boom.
The "International Building Code", about 10 years ago, intended to come out with their own electrical code. Fortunately they abandoned it.
--
bud--

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On 2/12/2011 11:05 AM, bud-- wrote:

Here in Birmingham, the inspectors use a modified code that has some differences from The NEC. I never argue with the inspector and say yes sir, do what they want and never have a problem. What I've seen of old K&T are soldered splices wrapped in friction tape. The electricians back then had a pump up blow torch heating a big hunk of a soldering iron to solder the connections. About 40 years ago, I was working for an electrical supply house in central Alabamastan and we supplied material for saw mills out in the sticks. The crazy old electricians were running 440/480 volt 3 phase circuits by rolling out #4 and #6 bare copper wire on the floor of the sawmill and covering it with a layer of sawdust. It was the way they had always done it and they weren't going to change. Heck, it's probably still being done like that. :-)
TDD
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My grandfather taught me to do an acceptable electrical solder joint. He made me do at least a couple of hundred of them before he said I was proficient at it. Years later he told me I did fine after about the first 10, all the rest were just to keep me busy. Since then Ive see a couple of electricians and a couple of electrical engineers attempt such a splice. Its a dieing skill.
Not sure what was code back in the day of K&T but I saw a house wired with K&T that was done beautifully. Had to be all ripped out. Neutral buss was a length of pipe running down the middle of the house. This was mid 70's, house built around 1890, before electricity was available. Think electricity was added around 1920.
Jimmie
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On 2/13/2011 8:18 PM, JIMMIE wrote:

Mebbe 8-9 years ago, I was prepping my late grandmother's 1961 house for sale, and changing out a failed porcelain fixture in the open basement ceiling. I was more than a little surprised to find soldered joints in the octagon box it was attached to. Fortunately the pigtails were long enough to reuse, and didn't seem brittle at all.
When I put 4 similar lights in basement here, after fighting to get the 12-2 on the double set of screws on the fixture, and stuffed back into box, I did the rest with pigtails. Much easier. (I had the 12-2 handy, and didn't feel like going out and buying 14-2.)
--
aem sends...

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On 2/9/2011 9:25 PM, The Daring Dufas wrote:

I needed some of the bright red cotton covered wire for inside a 1940's juke box, but I couldn't find it then. Only part of the juke run, (certain serial numbers) used that color (inside where no one can see) so I had to use the gold like most of those jukes had. It seems it was common to run out of a color wire and use something else. Stamped on a lot of 60's pinball machine schematics was something like: "Due to wire shortages wire colors on this schematic may or may not match actual wire colors in machine." And they had a lot of colors, then with 1 or 2 different color strips also. That sucked when it came down to tracing wires.
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On Tue, 8 Feb 2011 05:25:19 -0800 (PST), deadgoose

Yes, that's very handy to know. In this case, the strain is not inside where it connects, it's right at the opening. The cord gets bent back and forth and over time the wires inside break, causing a short. I long ago replaced the bare wires wrapped around the screws with crimp terminals, so that's working great. Also, there isn't room inside there for a knot, but this is a nice trick that I'll file away somewhere for future use.
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On Tue, 8 Feb 2011 08:30:56 -0500, "Stormin Mormon"

I also didn't say anything about the case wearing through the insulation. Methinks thou hast spent too much time reading your Book of Moron and not enough reading posts carefully.
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On 2/8/2011 8:25 AM, deadgoose wrote:

That picture is bothering me. Put more of the dang wire under the screws!!!!!!!!!!!
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