15 foot rule?

[scratch 10]

any one ever hear of the 15 foot rule? I had one guy tell me that I can use #8 wire for my

100 amp christmas light sub panel, its about 4 feet from the main panel. I didnt do it, i used #2 (had it laying around). i was just wonder if thats true.

[Tony Furst 0]

I've never heard of the fifteen foot rule. You did the right thing using the #2 wire even with the short distance.

Tony

[Toymakr000 1]

What? That's a weird one! That sounds dangerous...A wire that's undersized will still burn even if it's short in length....Where did that rule come from?

[scratch 10]

thanks i alway like a second opinion. makes me sleep better. thanks again

[Amazingmg 10]

I think he meant the 10-ft feeder tap rule [240.21((1)] —

You don't have to install an OCPD at the tap point of a feeder tap if its length doesn't exceed 10 ft and if it meets the following requirements:

• The ampacity of the tap conductor is not less than the computed load in accordance with Art. 220, and not less than the rating of the device supplied by the tap conductors or the OCPD at the termination of the tap conductors.
  
• The tap conductors aren't extended beyond the equipment they supply.
  
• The tap conductors are installed in a raceway if they leave the enclosure.
  
• The tap conductors have an ampacity of no less than 10% of the ampacity of the OCPD from which the conductors are tapped.
  

You would still need 100A (like your #2) rated wire for the 100A sub-panel or put a 50A main in the sub-panel and use the #8.

[CUTTHEMUSIC 0]

any one ever hear of the 15 foot rule? I had one guy tell me that I can use #8 wire for my

100 amp christmas light sub panel, its about 4 feet from the main panel. I didnt do it, i used #2 (had it laying around). i was just wonder if thats true.

He is absolutely correct about the 15 foot rule. The rule states that if you use the wrong size wire you should stand back 15 feet and watch the fire!

[scratch 10]

He is absolutely correct about the 15 foot rule. The rule states that if you use the wrong size wire you should stand back 15 feet and watch the fire!

I like that

[NH - Dave 23]

Best rule of thumb for wire size is to use the max size that the breaker can take. This info is printed on the breaker itself. Cant go wrong with manufacturers recommendations!

"Step back 15-foot - that's rich!!"

Edited December 3, 2010 by NH - Dave

[thevikester 12]

He is absolutely correct about the 15 foot rule. The rule states that if you use the wrong size wire you should stand back 15 feet and watch the fire!

That right there is worth the price of admission..thanks forthe laugh!