Double Taps

Gentlemen forgive me for posting on the Canadian thread without knowledge of your codes.

I have a question though, is there a provision in the code that would allow a manufacturer’s guidelines to be followed?


…realizing it was the Canadian thread.:oops: :oops:

Boy, do I feel silly.#-o

Please ignore my posts or use them in the USA.

All are welcome this is an open board.

I will be checking with the ESA (Electrical Safety Assoc) today.

Most certianly. If a product has been approved for use in Canada, then the manufactures instruction for use apply and superceed that of the codes.

I don’t understand how a Square D can be double tapped in light of the fact that the same conditions will be present on a D as with any other double tap. There is a likely hood of overload if both circuits are utilized at same time. (i.e. two 1500 watt heaters pluged into two different circuits but both circuits are on one breaker, Square D or otherwise.

Have not had a code book for 20 years but do know in the old code Book there was one line that said subject to the individual inspectors interpretation ( Or something close ). this was back when Ont Hydro was the power . If an inspector said some thing and you wish to over ride him it was a lot of work and very difficult . Much easier to go along with what he wanted and it made your future work easier to go with the flow.

Roy Cooke … R.H.I…

Larry please do not stop posting here you are most welcome and you just might give us some great ideas .
Roy Cooke … R.H. I.

My understanding of the ontario code is the only double tap allowed would before the transformer for the house door bell system if mounted on the panel. That is the information I got when takeing the electrical course from Humber.

I don’t think that the load is the problem. My understanding is that even with the same guage wires, it is possible that the clamping pressure may not be equal. This may be from very slight difference in the manufactured wire diameter even though they are the same guage, orientation of the wire under the clamp, thermal differences due to load demands, etc. At any rate, if the clamping pressure is not equal on both wires the wire with less clamping force could come loose. Stranded wire does not have this problem because all the stands are bundled together with the insulation.

The clamp of the Square D is designed to hold both the wire securely at the same time. The amount of load is not the factor. A single wire could run to a junction and then separate into two or more circuits.

Lets say you had a 15amp breaker with two 14 gauge wires double tapped on to it. One circuit is drawing 9 amps and the other circuit draws 7 amps. The amount of draw through the breaker is 16 amps so it trips. Well below and overloading through either of the wires.

I think double tapping has more to do with one of the wires from coming loose. I don’t think it has to do overloading.

I would think that the rule of no more than 12 devices allowed on a 15 amp circuit would be violated if you allowed double taps. It is not out of the realm
of possibility to see more than the allowed limit of devices drawing on 1 circuit breaker. Therefor double taps are a no no imho.


Lets say that you had a double tapped 15amp breaker and each of the circuits were 14ga wire with 10 devices on each wire. That means that you have a total of 20 devices being served by the one breaker (yes against rule 12-3000) but is there any combination(s) of load you can put on the circuit that would cause the wires to overheat or other damage before the breaker trips?

This is the way I see it too.

And thanks guys, I just thought I may have been confusing some with our NEC vs your CEC…wasn’t my intention. :wink:

Many are talking about double taps and how may outlets are permitted and lots of other things including what code it is covered by ,etcetera.
The main thing wrong with double taps is strictly one wire can not get enough pressure to carry the load. Poor connection leads to resistance this leads to heating .Heating leads to more resistance which causes more heat
And eventually a problem . It can be the wire breaks or worse a fire . Number 14 solid and a bell transformer are still double taps . Write them up protest your self. Past experience for me is most people do not follow many of our finding. This is their problem I do my part write hard talk soft miss nothing and Cover my a$$ to stay out of court. Sq D is the only breaker I know in the residential area that permits double tapping ,then the wires must be the same size and both solid or stranded not mixed.
Roy Cooke sr… R.H.I. …

Well the way I see it at least with double taps its black and white. The code says specifically not to. There is no provision for manufactures specific breaker to allow this. Just because Square D makes a breaker that can be double tapped, doesn’t mean it has to be used. How much do three breakers cost? $20-50 tops! How much time to put three breakers in and do it right? Electrician time for an hour to do the work $75-100. That is not an expensive repair and should theoretically should not be a deal breaker.

Right on Ray, I agree two taps on one breaker is a code violation. PERIOD.
When I find one I flag it. “another breaker is required so that the double tap can be eliminated”. If there is any drought as to my clients ability I call for a licensed electrician to fix.
Last year I was called back my a client from the year before and the house had a 14 guage double tapped into one side of the two pole 30 amp dryer breaker. This was a year after my inspection and his purchase. He has not fixed it.

Some people never learn and some still later.

Received an answer from ESA re double taps. Here is the response for your your files and knowledge base, as if we are not already on information overload. :wink:

I am answering your question by splitting it into two questions.

*1. Does the code prevent terminating two conductors to a single branch circuit breaker?

  • The code does not prevent connecting two conductors to a single branch circuit breaker provided that the breaker is approved for that purpose. As you suggest, the Square D 15 - 30 amp single pole Type QO breaker is approved for the termination of two conductors.
  1. Does the code prevent using a branch circuit panelboard enclosure as a junction box or a raceway?*
    The code states that the enclosure shall be permitted to be used as a junction box if wiring is being added to an enclosure forming part of an existing installation and the conductors, splices and taps do not fill the wiring space at any cross-section to more than 75% of the cross-sectional area of the space.*
    Ontario Electrical Safety Code Rules 2-034, 12-3034.

Code Specialist
Electrical Safety Authority

ESA encourages the use of Licensed Electrical Contractors.
**All electrical work requires a Certificate of Inspection from the Electrical Safety Authority.
Original question:
**comments: Two weeks ago I sent a question in via this contact form. I never did receive a response to question lett alone an receipt that this contact form was receive.

My original question was regarding double taps in residential electrical panels, whether they are permitted or not. The ESCode states they are not, but I have been seeing many double taps and there has been a ESA sticker on the panel. I am also aware that Square D breakers allow two wires, but what is ESA opinion?

Thank you.
Raymond Wand

thanks Raymond we are all just a little smarter .
Roy Cooke sr

The point here is not what is ‘allowed’ by codes or what is ‘allowed’ by a panel manufacturer or what realtors ‘want’ to believe (especially if it makes their lives easier).

The point is best practices and safety and serving the client.

I have had many sparkys dress me down for callong out double (and triple!!!) taps.

I stay calm and ask them, “You say it is OK, in writing, on your letterhead and with your license number and insurance certification printed, I have no problem.” They just look at me (kind of confused looking) and say “It’s code!”. I then respond "Hey, guy, you want the liability, you want to take the liability off my, and my client’s shoulders, fine by me! Let’s just get it all good and documented.’

Most times, they just say a bad word and walk away. :mrgreen: :mrgreen: :mrgreen:

Hope this helps.

And what pray tell is the “bad word” they use? If the code says it is not allowed it is not allowed. If you find a double tap and an ESA sticker on the panel I would be calling the ESA and letting them take the liability.

Dear Larry;

I work in the states. We are not nearly as civilized as you are in the Great White North.

Around here (Chicago area) the Unions rule. They think they can get away with this because they own the governments and write the ‘code’. (Try to read the City of Chicago Electrical Code sometime. It is, by far, the most complicated construct of modern man!!!).

So, I put the liability on them. :mrgreen:

Few decide to accept it. \:D/