Control/Dimming Measuring Conductor Size

[de27192]

Not sure if this is the best forum but there doesn't appear to be a general electrical thread...

Is there a way to easily measure - using maybe verniers - the size of a conductor inside multicore cable? Obviously the size is given in mm2 so I need more than the diameter - although would simple maths do it - IE πR² ?

I'm in a completely ridiculous situation in a new build where there are 2 electrical contractors on site, one is insisting that the wiring they've installed is 10mm, the other is insisting it's only 6mm, and I need to play referee. They've stuck a 63A socket on it (240V) so if I can't find a way to measure it I'm going to have to plug all my molefays in and see if it gets hot...

 

[theatricalmatt]

Shouldn't it be marked on the outside jacket of the cable?

Is the 63A socket removable?

Since it's an installation, do you have access to cable remnants that were cut off, or even left on the spool or reel?

 

[de27192]

Sorry should have explained things I already tried:

Shouldn't it be marked on the outside jacket of the cable?

Sadly it's not. Or at least, not on the small section of cable poking out of the wall.

Is the 63A socket removable?

Yes I can get inside and measure on the actual conductors themselves.

Since it's an installation, do you have access to cable remnants that were cut off, or even left on the spool or reel?

Sadly not.

 

[techieman33]

Sadly even the markings can't be fully trusted. There have been issues with wire coming out of China that is undersized for that markings that the jacket carries.

 

[de27192]

Sadly even the markings can't be fully trusted. There have been issues with wire coming out of China that is undersized for that markings that the jacket carries.

Yes and these are the sort of sparkies who would use it!

Hence I really want to know if I can use any simple measuring system to put a pair of verniers to the conductor (obviously isolated) and determine the actual conductor size.

 

[DavidNorth]

Would this help you?? I use it [and others] from time to time.

http://www.google.com/url?sa=t&rct=...es.pdf&usg=AFQjCNEan1JOHCfAAB3jyHWEdxNYcnI7uw

David

 

[de27192]

Perfect, that seems to be exactly what I need.

 

[JD]

Haven't ever thought about this. I guess after enough years you can tell just by the look and feel of the copper.
A fast, low-tech method for questionable sizes would be to grab some crimps as see which ones fit the conductor best. A few years back, I remember being thrown when trying to figure out some speaker wire. I was unaware at the time that 13 gauge was a valid size!

 

[de27192]

Haven't ever thought about this. I guess after enough years you can tell just by the look and feel of the copper.
A fast, low-tech method for questionable sizes would be to grab some crimps as see which ones fit the conductor best.

I appreciate your input but like, the whole reason we're in this situation is because it looks like 6mm to me, looks like 6mm to one of our electricians, but not to the other. "Looks too small to me" isn't cutting it, hence I was after some measurements. I appreciate there's going to be a bit of variation. As I said, not being rude or knocking your input, it's just one of those situations where you have to be watertight about it.

Honestly, the whole 'new installs' business really isn't as easy as you'd like to think. To every common sense precaution you can take, your building contractors will have already figured out a way to skirt around it. They are professional con artists, and they play consumer rights to their favour. I hadn't appreciated it before but it really is a minefield.

 

[Chris15]

It might not solve the situation at hand, but it's worth noting that modern insulation allows for a thinner insulation layer for the "same" dielectric properties, so overall conductor diameter can be reduced to what we become accustomed to...

 

[SteveB]

One solution is to trace back to breaker, if possible.

If installed correctly and even with taps, the wire size at the breaker should be the same in the pull box where you are seeing it. You can usually access the wires in the breaker panel.

 

[JD]

your building contractors will have already figured out a way to skirt around it.

We have flooding in our church... The reason we have flooding is the contractor saved himself a little money and left the last course of block out of the basement structure, leaving the church 12 inches lower than the architect had specified. 25 years of cleaning things up and the contractor has long since gone bankrupt. Yea, watch those contractors!