Double Taps

[rwand1]

I had a realtor tell me today that electricians are getting peeved at home inspectors for calling out double taps. Yet in the home that was inspected there were three double taps, with room for more breakers. I called it out and suggested the vendor repair prior to closing of title. The building permit was okay, and there was a ESA orange sticker on the panel, but no dates or anyother mark on it.

So what is the story, I like to think those electricians are wrong, because double taps lead to nuisance trips because you have doubled the load?

If the building permit is signed off, and the panel was done by an electrician is it right? I know the electricians are left to their good discretion, but I also know ESA inspectors only inspect a representitive number of new homes, not all of them, they entrust the electrican?

Confused.

[phinsperger]

I write them up also. I also inform the client about how common (I didn't say correct) it is.

[Larry D. Kage]

Originally Posted by rwand1

So what is the story, I like to think those electricians are wrong, because double taps lead to nuisance trips because you have doubled the load?

This seemed like a good explanation that I pulled from somewhere:

Double tapping and lugging can create hot spots on breakers and neutral bars if not tightened to the correct torque and especially if two different size conductors are used. Because the hot and neutral wires are current carrying conductors, the chance is then greater for potential hot spots. If the double tap or lug becomes lose, it begins to arc. As it arcs it builds up carbon. Carbon is then resistance and with the more carbon buildup the more difficult it is for the conductor to make contact....thus increasing the current. End result can be the breaker tripping because of the loose conection (excessive current exceeding the rating of the breaker), or signs of overheating such as discolored wires, melted wires, etc, or worse yet...fire!

110.14(A)..."Terminals for more than one conductor and terminals used to connect aluminum shall be so identified."

[Roy D. Cooke, Sr]

Originally Posted by rwand1

I had a realtor tell me today that electricians are getting peeved at home inspectors for calling out double taps. Yet in the home that was inspected there were three double taps, with room for more breakers. I called it out and suggested the vendor repair prior to closing of title. The building permit was okay, and there was a ESA orange sticker on the panel, but no dates or anyother mark on it.

So what is the story, I like to think those electricians are wrong, because double taps lead to nuisance trips because you have doubled the load?

If the building permit is signed off, and the panel was done by an electrician is it right? I know the electricians are left to their good discretion, but I also know ESA inspectors only inspect a representitive number of new homes, not all of them, they entrust the electrican?

Confused.

I would expect the ESA sticker was put there by the electrictian who did the job. They now only inspect a very small amount of the homes that are wired by an established contractor. It might be a simple thing for the purchaser to call the original contractor and state that a home inspector said that double taps are not allowed in most cases ( SQ D is one ) and that they are wondering if they should call the local hydro authority. I expect the original contractor will fix it for free as he does not want ESA to know he scewed up .
Roy Cooke .... RHI........... Cahpi-on
A HAPPY NACHI member.

[Brian E. Kelly]

Originally Posted by lkage

This seemed like a good explanation that I pulled from somewhere:

Double tapping and lugging can create hot spots on breakers and neutral bars if not tightened to the correct torque and especially if two different size conductors are used. Because the hot and neutral wires are current carrying conductors, the chance is then greater for potential hot spots. If the double tap or lug becomes lose, it begins to arc. As it arcs it builds up carbon. Carbon is then resistance and with the more carbon buildup the more difficult it is for the conductor to make contact....thus increasing the current. End result can be the breaker tripping because of the loose conection (excessive current exceeding the rating of the breaker), or signs of overheating such as discolored wires, melted wires, etc, or worse yet...fire!

110.14(A)..."Terminals for more than one conductor and terminals used to connect aluminum shall be so identified."

Many Square panels allow two same size conductors.

Originally Posted by bkelly2

Many Square panels allow two same size conductors.

But only if the load is not maxed out



I always make note of the fact that there is double tapped circuits, and make recommendation that the electrical panel be inspected by a licensed electrician.

[Larry D. Kage]

Double tapping and lugging can create hot spots on breakers and neutral bars if not tightened to the correct torque and especially if two different size conductors are used.

Originally Posted by bkelly2

Many Square panels allow two same size conductors.

It does say "and"...relating to double tapping/lugging hot spots but you're correct many Sq. D breakers allow two same size conductors.

[rwand1]

Thanks guys. I will be contacting ESA this week and see if I can get a policy statement from them in regards to double taps.

Unfortunately it is the realtors who have to take the word of a licenced electrician over that of a home inspector. Still don't understand how a Square D double tap can be any different from any other double tapped breaker as it is still possible to double the load, thus resulting in tripping.

Thanks again.

[phinsperger]

Originally Posted by rwand1

Thanks guys. I will be contacting ESA this week and see if I can get a policy statement from them in regards to double taps.

Raymond, If they provide you with a statement please post it for all to see.

[rwand1]

To quote Roy Cooke Sr., "you bet ya!"

[Larry D. Kage]

Originally Posted by rwand1

Still don't understand how a Square D double tap can be any different from any other double tapped breaker as it is still possible to double the load, thus resulting in tripping.

Most breakers aren't made for two wires like this Sq. D pic:

I can go by what I see such as whether the manufacturer allows 2 wire on a breaker but I don't do load calculations for the 2 wire loads.

[jwortham]

I call out the double-taps.

If the electrician then says they are fine, and signs off on them, not my concern. I've done my job advising my client.

I don't tell a realtor how to sell a house. They don't get to tell me how to inspect one.

[Brian E. Kelly]

Originally Posted by lkage

Most breakers aren't made for two wires like this Sq. D pic:

I can go by what I see such as whether the manufacturer allows 2 wire on a breaker but I don't do load calculations for the 2 wire loads.

Nice picture Larry, many times you can read the wiring diagram in the panel showing whether two conductors are allowed or not. I believe if they are allowed than it is not a double tap.

[Larry D. Kage]

Originally Posted by bkelly2

I believe if they are allowed than it is not a double tap.

Same here, Brian. I don't care to pay for the electricians trip out for no reason.

[Vern Mitchinson]

Rule 6-212 & 12-3034 Says "It is not correct to connect two or more wires to a circuit breaker or fuse."
From 7th edition of Alberta Book 1, Electrical code simplified (residential wiring)
Based on the 18th edition of the Canadian electrical code and Alberta amendments.
This code was printed in 1999. It may have changed in later editions.
I drought it. If anyone has a later edition that says something different I would like to hear it.
Anytime I see a double tap I flag it for a licensed electrician the repair.