Amperage Ratings

[robr]

I have a scale that has to be installed in a industrial blg. It is 120v, 25a, single phase, 100ft. away from panel. The NEC states that this circuit requires a 6ga THHN wires for this. My boss says this will never pull that much amperage. Am I right in what I want to do or do I do what he says which is wrong in my opinion? He wants me to put a 10ga wire on this.

 

[richwaskowitz]

Re: Amperage Ratings

#6 (65 amps per table 310-16)is quite a leap from #10 (30 amps per table 310-16 and 240-3(d)).

How about some more info?

Why did you state that the NEC requires #6?

 

[don_resqcapt19]

Re: Amperage Ratings

What section of the NEC requires #6 for a 25 amp load????
Don

 

[hillbilly]

Re: Amperage Ratings

If voltage drop is not a concern then #10 wire will suffice. At 100' and 25A (120V) load you will see about a 5V drop on #10cu. What is the actual load? 25A seems high for a scale.
Edit: If you are trying to limit the voltage drop to less than 2% then it will require #6 wire. Again this is if the load is truly 25A. What kind of scale is it?
steve

[ March 05, 2004, 11:04 AM: Message edited by: hillbilly ]

 

[robr]

Re: Amperage Ratings

This is a scale/wrapper combo so there is a 25a load on this. If you are running 25a load, 120v at 100ft distance then the book as I read it says you need a 6ga wire for a 3% drop. This was figured out using the voltage drop calculator on Mike Holt's site.

 

[don_resqcapt19]

Re: Amperage Ratings

The code does not cover voltage drop for this type of circuit. That is a design issue, not a code issue.
Don