Double Taps... Here we go again

Last week I inspected a 4 year old residence. Upon inspection of the electrical panel I found that the breaker (15 amp) had been double tapped with a door bell transformer and 14 ga. branch circuit. I called it out as requiring improvement. The panel had a ESA sticker on it which more or less stated that the electrical company who did the panel was approved by ESA, but the work by the approved electrician was not inspected but rather ESA audits at random the work.

Subsequently the homeowner and listing agent checked with the electrician he said its no problem. They also checked with the ESA inspector who said it was okay.

As I told my client at the time I suspected the neighbouring homes in the development were all likely double tapped and I see it time and time again. The vendor is willing to fix the problem but by providing alternative proof from higher authority that its okay. I told my client I will check with ESA because I believe ESA is contradicting themselves. ESA states its only a concern if its two branch circuits that are double tapped. Well… if a door bell and the second line under the terminal is not a single circuit. One is feeding the door bell and the other line is feeding off to something else. In all likely hood the door bell transformer will not overload the circuit. I also told my client that ESA has final say as they are the authority having jurisdiction and that I would ask my colleagues via this forum. I have also sent an email to ESA asking the same question as below. Also note below is an earlier inquiry about double tap and ESA reply. They seem to be contradicting themselves and this breaker is not a Square D. I think I am right but I can also understand ESA having final say, but don’t like the fact they are contradicting their own rules!


    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.
  2. 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 Message-----
From: []
Sent: Monday, March 27, 2006 8:31 AM
Subject: ESA email contact form

emaillist: yes
Client name: Raymond Wand
Client e-mail:
Client phone: 519-942-9496
phone: 519-942-9496
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

I heard back from ESA, and they said doorbells are not a concern so far as double taps, and its permissable, due to low current draw.

So thats the last time I will be calling those types of double taps. :slight_smile:

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Raymond I would still call it, as sooner or later someone, ESA, the expert neighbor, the second cousin twice removed or the famous insurance company is going to say different.

If I can jump in, the NEC has a rule against more than one wire under a terminal, but because the NEC givers precedence of manufactures instructions (ofcouse listed), manufactures like Square-D breakers (QO and HomeLine) can have two conductors (“double tap”). For future reference, look at the breaker, it is has torque specs for double conductors, you can be pretty sure it’s allowed.

Now like everything, read the codes, be careful what you read in forums. :wink:

P.S. “Double taps” are notorious for not allowing proper contact with the wires, causing arcing and burning, you cannot draw more than the breaker is allowed to. It will trip.




The problem is that its been demonstrated via the ESA that this is permissable in new construction. I told the ESA inspector that most likely the other homes in the neighbourhood most likely had the same double tapped door bells. The ESA inspector replied that I was likely right.

So why would I call out door bells when ESA says its okay? They have final word. It has caused the vendor, the realtors, and purchaser to fret needlessly. However I must admit not one of the parties said I was over officious.


Well what did I discover at todays inspection? Yes another double tap. Door bell transformer line to Stablock breaker. And the door bell wire was not securely fastened under the terminal! I pulled it right out! I even tried to secure it under the terminal with no luck. So much for ESA and their opinions!

The double tap is bottom left second breaker from bottom.

Follow up:

This is a reply I rec’d today from ESA Code Specialist.

I have also rec’d contrary info from ESA that states that such double taps are permissable.


You will find that even the ESA inspectors disagree with each other on this subject. To add other situations. Many ESA inspectors will overlook surge supression devices for the same reasons. Door bells have been accepted by the majority of ESA and Utility reps as ok for years.

I look at the conection and if it seems to be good and firm, I do not call them double taps, I mention that the door bell or Surge Suppresion device is connected in tandem with another circuit which has been an acceptable practice in the past



I agree that ESA inspectors in the field are okaying and electrician have been installing door bell transformers in this fashion. But the Code Specialist with ESA is quoted as stating:

“Double taps are permitted provided that the circuit breaker is approved and marked for termination of more than one conductor and both conductors are of the same size, material, and characteristics (solid or stranded).”

*"*With respect to a doorbell transformer, my experience is that the conductor is typically stranded and less than #14 AWG in size. Termination of that conductor together with a #14 AWG solid conductor on the same breaker is a violation of the code."

I am finding too many instances in the field were the tap is loose, and there is no way a Stablok breaker will clamp down on two different size wires (8ga vs. 14ga). I also do not like receiving two totally different views from a agency which is now contradicting itself. In reality I am going to persue this further with the code specialist and inform him that there is a concern because these double taps are not always secure.

It will be interesting to see what the reply will be. I also believe this is cost saving measure by electricians in the field.

Thanks for your post.

Assuming the breaker is designed for a double tap ie. Square D, using same guage solid wire as a jumper on the double tap and then using a Marr connector for securing the stranded wire from the door bell to the jumper wire should be OK. A simple fix. What do you think, Roy C.?


Thats the problem, in the field I am finding Stab-Lok breakers, and there is no pigtailing, the wire is directly under the terminal screw.

I have seen the same thing in other homes as well. Door bell or security system transformer leads double tapped to breaker. It can be difficult to get proper compression on mixed wires (stranded and solid) at the terminal.
As you have also found, sometimes the wires are easily pull out the loose connection. I can’t understand why the ESA is not more consistent in calling out these installations.

What bothers me is someone in ESA says one thing while another says something else from the same authority by the book . In other words it can’t be both ways? And the Code backs that up in my opinion. After all we are talking about electricity, possible arching ( I don’t know if door bell would arch with loose connection, … ?)

The arching would take place at the point of connection to the breaker. If the door bell transformer wire (stranded) is preventing the solid wire from making good contact with the breaker terminal you could have arching at that point. (my understanding)