Need some help please w/ elec cord & digital multimeter (long post, Sorry!)

[Malcolm McLeod]

So what kind of cable clamps should I have used exactly? I wasn't really happy with these but it was pretty much all I saw (or very similar) at those big box stores. If there's something better I'd like to use that.

This is simple style (not sure if it will fit your specific cord diameter). This is a bit more ($$ and function).

Edit: I've used these before, too. On control panel penetrations, they work well - - not sure how they would last on a rig like yours, as they might get tossed around???

[Marc Jeske]

Even though Malcolm is technically correct, I am quite sure 99% of the guys on this forum would do it w the components Mike purchased... as would most any typical Electrician making one for home shop or even to carry in his truck

OSHA Industrial or heavy everyday rough use Commercial application are different, but far from the need here.

My opinion anyway.

Marc

[Matt Marsh]

That’s why i said we can get away with it at home, .... but.

I’ve seen this same setup fail so many times. The new raised covers are indeed better now that the receptacle is held at each end, rather than just the center 6-32, but because the receptacle sits proud of the cover, it often breaks, when the cord is tossed around during use. Another problem with these, is the equipment ground connection to the box. Because the ground screw protrudes through to the outside of the box, it often loosens up over time. This setup gives you one additional receptacle, with an option for another duplex if a double duplex raised cover is used. A cord splitter such as the one at the link below is UL listed for portable use, and is a much better choice.

https://www.amazon.com/Yellow-Jacket...=Cord+splitter


Even better, is a cord with a splitter AND an in-line GFCI protector like this one.

https://www.amazon.com/Outdoor-Light...splitter&psc=1

[Matt Marsh]

B6AB0D84-2035-4FFC-BDC0-8E2101ACD445.jpegA Romex connector is what you have there, it is not listed for use with cord. The connector pictured above is a commonly used type, and is listed for use with cord. It is usually referred to as a "CGB". The type with the "Chinese finger" strain relief is really only needed when a cord is used as a pendant.

[Mike Manning]

Just to update everyone, I finished my extension cord from hell on Wed and it's working very well. Thanks to everyone for their feedback but especially to Marc for talking me through what I need to do to build this safely.

Marc,
I know I've still got some homework to do on the GFCI. Will try to do it today or this weekend and let you know! Thanks a ton!

Mike

[Matt Marsh]

Because electrical safety has been a large part of my life since I started in the trade almost 42 years ago, I feel compelled to follow up on this. This particular assembly is one of the most common OSHA violations. It is an illegal assembly for good reasons, because it has proven itself to be unsafe. I realize that yes, some of you have been using this setup for years without any problems, but OSHA deals with numbers, and the numbers prove why it’s not a safe assembly.

For those interested, here is a link to OSHA’s site that outlines their rules for these homemade portable power cords. Pay particular attention to the numbered section toward the bottom of the page, especially sub-section 2.

https://www.osha.gov/pls/oshaweb/owa...ONS&p_id=20579