Engineer

[joseec]

I would like to know what is the maximum percentage of unbalance load permited by NEC

 

[al hildenbrand]

As stated, your question is vague.

The NEC doesn't give a percentage.

What's the voltage, current, number of phases, reactive or resistive load, depth of your pocket?

 

[dcspector]

Al. Good reply. I was confused as to what..... Neutral balancing.... or what?

 

[charlie b]

Although I don?t know where to find it offhand, I believe there is at least one statement in the NEC to the effect that loads should be balanced as closely as practical among the two or three phases in a panelboard. But I am certain that there is no maximum number stated. You should keep in mind that we can design and install panels that have loads perfectly balanced among all the phases, but the owner can turn on all the loads on one phase and none of the loads on the other phases. The NEC has nothing to say about this.

Exactly what are you looking for?

 

[ptonsparky]

Not be a SA, but when the overloads on your motors start tripping because of the resultant voltage imbalance, you've exceeded the limits.