gauging wire size

[The electron man]

On old panels or wires that don't have the wire size on them what's the best way to tell what size wire it is ?

 

[ptonsparky]

On old panels or wires that don't have the wire size on them what's the best way to tell what size wire it is ?

Get an old electrician to look at it, but not always. I'm an example of not always.
You need to measure the diameter and do the math to calculate the area. The NEC has tables.

Eta: the bare conductor itself, not the insulation

 

[electrofelon]

https://www.amazon.com/Utility-Dial-Caliper-Science-Purchase/dp/B00O985RRU

 

[marmathsen]

https://www.amazon.com/Utility-Dial-Caliper-Science-Purchase/dp/B00O985RRU

Is there an insulated version of that model?

Rob G, Seattle

 

[tom baker]

I have a plastic dial mccrometer by general

 

[marmathsen]

I have a plastic dial mccrometer by general

I already ordered some plastic calipers after reading this comment. Thanks for the idea!

Rob G, Seattle

 

[infinity]

I already ordered some plastic calipers after reading this comment. Thanks for the idea!

Rob G, Seattle

Just realize that if you're measuring the insulation that different insulations on the same size conductor will have different diameters.

 

[Joethemechanic]

I used to have a round plastic thing with notches corresponding to AWG size. I can't remember where I got it, or what happened to it. I think it was a freebie from someone. I don't see why you couldn't make one. Basically a "Go-No Go" gauge. They were invented By Whitworth to eliminate production errors.



Yes that Whitworth

 

[marmathsen]

I used to have a round plastic thing with notches corresponding to AWG size. I can't remember where I got it, or what happened to it. I think it was a freebie from someone. I don't see why you couldn't make one. Basically a "Go-No Go" gauge. They were invented By Whitworth to eliminate production errors.

View attachment 2566052

Yes that Whitworth

I found these yesterday when I was looking around online.

Inspection Gauges

Helpful tips. Watch these videos! http://www.inspectionwiregauges.com/videos.html

www.inspectionwiregauges.com

Rob G, Seattle

 

[marmathsen]

Just realize that if you're measuring the insulation that different insulations on the same size conductor will have different diameters.

Of course. Often there's a little bare exposed right next to the lug.

I picture making a little cheat sheet. Possibly adding dimensions of the insulation as well including older wiring.

Rob G, Seattle