Double tapping on a circuit breaker
- Thread starter tonymazz
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roger deas
Member
- Location
- North_Carolina
Re: Double tapping on a circuit breaker
Tony, "most" manufacturers breakers through 30 amps are listed for two wires per terminal. So you have probably been in error. You can find this information on their web sites.
Roger
Tony, "most" manufacturers breakers through 30 amps are listed for two wires per terminal. So you have probably been in error. You can find this information on their web sites.
Roger
Re: Double tapping on a circuit breaker
Interesting...the only breaker I know of is the Square D (QO and QOB)and indicate so with a small plate under the screw so that a wire can be secured on both sides of the screw.
As far as double tapping goes I thought it should not be practiced because the mechanical connection between the wire and terminal lug on breaker isn't technically secure with more than a single wire. this can cause arching, excess resistance, heat etc.
Which other breakers are designed for double wires ?....other than say a whole house surge protection...
Interesting...the only breaker I know of is the Square D (QO and QOB)and indicate so with a small plate under the screw so that a wire can be secured on both sides of the screw.
As far as double tapping goes I thought it should not be practiced because the mechanical connection between the wire and terminal lug on breaker isn't technically secure with more than a single wire. this can cause arching, excess resistance, heat etc.
Which other breakers are designed for double wires ?....other than say a whole house surge protection...
roger deas
Member
- Location
- North_Carolina
Re: Double tapping on a circuit breaker
Tony, looking at the Cutler Hammer Quick Selector Catalog the CH 15 to 30 amp plug on breakers with HM or HD suffix are listed for (2) # 14-10, and can be a combination of solid and stranded. Each installation would have to be checked, but there is really no problem if the torque specs are followed.
Roger
[ March 05, 2003, 04:36 PM: Message edited by: roger deas ]
Tony, looking at the Cutler Hammer Quick Selector Catalog the CH 15 to 30 amp plug on breakers with HM or HD suffix are listed for (2) # 14-10, and can be a combination of solid and stranded. Each installation would have to be checked, but there is really no problem if the torque specs are followed.
Roger
[ March 05, 2003, 04:36 PM: Message edited by: roger deas ]
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
Re: Double tapping on a circuit breaker
Roger
You just made me think of something!
If I had "X" brand breaker and it was allowed to be double tapped, could I "upgrade" it, (meaning it has one wire under it properly torqued) and add another wire?
Mike P.
Roger
You just made me think of something!
If I had "X" brand breaker and it was allowed to be double tapped, could I "upgrade" it, (meaning it has one wire under it properly torqued) and add another wire?
Mike P.
Re: Double tapping on a circuit breaker
Mike, why not? I know the board has been through the torque conversation more than once. I personally still use the old method. (feel) The idea that a screw can only be torqued once is not true in my opinion. If this was the case, we would never be able to lift a wire for trouble shooting with out replacing the breaker. Of course this might not be what you're asking.
I've been off track before and I'm sure I will be again.
Roger
Mike, why not? I know the board has been through the torque conversation more than once. I personally still use the old method. (feel) The idea that a screw can only be torqued once is not true in my opinion. If this was the case, we would never be able to lift a wire for trouble shooting with out replacing the breaker. Of course this might not be what you're asking.
I've been off track before and I'm sure I will be again.
Roger
daveselectric
Member
- Location
- Ohio
Re: Double tapping on a circuit breaker
Double tapping defeats the purpose of running the additional purpose. The breaker will be subject to trippng because of the additional load.
Double tapping defeats the purpose of running the additional purpose. The breaker will be subject to trippng because of the additional load.
daveselectric
Member
- Location
- Ohio
Re: Double tapping on a circuit breaker
Sorry about the previous post. It should read..... additional circuit....
Sorry about the previous post. It should read..... additional circuit....
bphgravity
Senior Member
- Location
- Florida
Re: Double tapping on a circuit breaker
Why not make a splice and pigtail one conductor to the breaker? As long as the two circuits don't exceed 210.19 and the panel has enough room for the splice. This eliminates the problem all together.
Why not make a splice and pigtail one conductor to the breaker? As long as the two circuits don't exceed 210.19 and the panel has enough room for the splice. This eliminates the problem all together.
luke warmwater
Senior Member
Re: Double tapping on a circuit breaker
I would say that of all the Home Inspector reports that I've seen, Doubble tapping is one of the most common electrical items(along with 3-prong outlets with no ground). We had a long thread about this on the Old forum. Square D QO and Homeline are both listed for 2 wires and Cutler Hammer CH is also.
We don't just add another breaker if the one installed is not listed for 2 wires. 2 wires does not automatically mean 2 circuts. More often than not it is another convenience outlet added to a circut. Very few times do you ever see two large amp draw devices double tapped. Pigtail the wires is most often all that is needed.
I would say that of all the Home Inspector reports that I've seen, Doubble tapping is one of the most common electrical items(along with 3-prong outlets with no ground). We had a long thread about this on the Old forum. Square D QO and Homeline are both listed for 2 wires and Cutler Hammer CH is also.
We don't just add another breaker if the one installed is not listed for 2 wires. 2 wires does not automatically mean 2 circuts. More often than not it is another convenience outlet added to a circut. Very few times do you ever see two large amp draw devices double tapped. Pigtail the wires is most often all that is needed.
luke warmwater
Senior Member
Re: Double tapping on a circuit breaker
bph, you read my mind, and typed faster too.
bph, you read my mind, and typed faster too.
rick caudill
New member
- Location
- Ohio
Re: Double tapping on a circuit breaker
bph, Why would you want to make additional connections? The most secure and most easily checked connection would be at the breaker lug.
bph, Why would you want to make additional connections? The most secure and most easily checked connection would be at the breaker lug.
Re: Double tapping on a circuit breaker
I am really finding this discussion enlightening. As a home inspector the issues of double tapping was more or less drilled into our analysis of the main panel.
While we are only looking for some obvious issues like;
- Ampacity of the service entrance wires to main breaker size
- Panel capacity
- Branch circuit awg size -to- breaker capacity
- noting any aluminum wiring on branch circuits i.e. home built in the 70's
- double tapping on breakers ....(could be an indication of DIY) but now you guys are saying that it is done for various reasons.....with some disagreement.
- grounding of panel, main system ground
- general condition of the panel, i.e. water penetration, arching, signs of overheated wires, and other hodge podge
Are there other things that you as licensed, trained electricians would like a home inspector to look for on the panel...that may be would trigger a call for an electrician to correct..??
Just wondering...
Thanks for your insight!
Tony
I am really finding this discussion enlightening. As a home inspector the issues of double tapping was more or less drilled into our analysis of the main panel.
While we are only looking for some obvious issues like;
- Ampacity of the service entrance wires to main breaker size
- Panel capacity
- Branch circuit awg size -to- breaker capacity
- noting any aluminum wiring on branch circuits i.e. home built in the 70's
- double tapping on breakers ....(could be an indication of DIY) but now you guys are saying that it is done for various reasons.....with some disagreement.
- grounding of panel, main system ground
- general condition of the panel, i.e. water penetration, arching, signs of overheated wires, and other hodge podge
Are there other things that you as licensed, trained electricians would like a home inspector to look for on the panel...that may be would trigger a call for an electrician to correct..??
Just wondering...
Thanks for your insight!
Tony
bphgravity
Senior Member
- Location
- Florida
Re: Double tapping on a circuit breaker
Rick, if the splice is made in accordance with 110.14(B), then the connection should and will be just as good as if on the breaker terminal. In some cases, the heating effects on breaker terminals causes loosening over a period of time. If a splice is done right, it should never fail. It is only a suggestion and option.
Rick, if the splice is made in accordance with 110.14(B), then the connection should and will be just as good as if on the breaker terminal. In some cases, the heating effects on breaker terminals causes loosening over a period of time. If a splice is done right, it should never fail. It is only a suggestion and option.
bphgravity
Senior Member
- Location
- Florida
Re: Double tapping on a circuit breaker
Tony, a good thing to report is neutral or grounded conductors sharing a terminal space. This is not allowed per Article 408.21 of the 2002 NEC and it can be easily identified within a panel. Proper terminal torquing is usually needed on older panels as well.
Tony, a good thing to report is neutral or grounded conductors sharing a terminal space. This is not allowed per Article 408.21 of the 2002 NEC and it can be easily identified within a panel. Proper terminal torquing is usually needed on older panels as well.
Re: Double tapping on a circuit breaker
bph, I can not think of one time I have ever seen a problem with loosening or heating problems on a double tapped breaker that was designed for this application. If I were going to run a circuit two directions immediately after leaving the panel, I would save the expense of a jbox, cover, connectors, wire nuts, and labor, and simply terminate on the breaker.
Tony,
You would have to look at articles 430 and 440.
Roger
[ March 06, 2003, 04:39 PM: Message edited by: roger ]
bph, I can not think of one time I have ever seen a problem with loosening or heating problems on a double tapped breaker that was designed for this application. If I were going to run a circuit two directions immediately after leaving the panel, I would save the expense of a jbox, cover, connectors, wire nuts, and labor, and simply terminate on the breaker.
Tony,
be carefull here, if you are looking at HVAC or motor circuits, the conductor can be considerably smaller than the OCP per articles 310 and 240 norms.
You would have to look at articles 430 and 440.
Roger
[ March 06, 2003, 04:39 PM: Message edited by: roger ]
bphgravity
Senior Member
- Location
- Florida
Re: Double tapping on a circuit breaker
As a service contractor, I have had to retorque terminals in service panels on nearly every panel over 5 years old that I a have performed work in. The double tapped and single ones alike. The point I was trying to make, is that breaker terminals are not free from potential problems just as wire splicing can have. Expense should be the last concern. Again, either way will work if you have a breaker type that is listed for more than one conductor. Chances are, you don't. So I thought I would provide an option. I am not trying to say you are wrong. 2 opinions, two good ways.
As a service contractor, I have had to retorque terminals in service panels on nearly every panel over 5 years old that I a have performed work in. The double tapped and single ones alike. The point I was trying to make, is that breaker terminals are not free from potential problems just as wire splicing can have. Expense should be the last concern. Again, either way will work if you have a breaker type that is listed for more than one conductor. Chances are, you don't. So I thought I would provide an option. I am not trying to say you are wrong. 2 opinions, two good ways.
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
Re: Double tapping on a circuit breaker
Roger
"I've been off track before and I'm sure I will be again."
Where I was going is: do you cut the wire and strip a new section of wire or do you just reinstall it.
I thought the torque was for the wire and not the screw.
Mike P.
Roger
"I've been off track before and I'm sure I will be again."
Where I was going is: do you cut the wire and strip a new section of wire or do you just reinstall it.
I thought the torque was for the wire and not the screw.
Mike P.
Re: Double tapping on a circuit breaker
Mike, I think if we are talking about stranded it would definatly need to be evaluated. My reference to the screw goes back to my engine building days as far as stretching threads either in the seat or on the bolt. I allways thought that was hearsay too.
bhp, any mechanical connection will change over time. When retorqueing, you would need to go back to the same conditions (ambient temps for example) that were present the day it was first done to get an acurate feel of how much change occured.
Unfortunately, "expense" is a driving factor in competitive bidding. I know you are looking at a single installation, but let's say you have bid a subdivision, you have to look at savings that would be allowed by code. Also
Now let's look back at Tony's question. Yes, by the code, if the breaker is listed for two wires it is not a violation, and if it was written up Tony is wrong.
What this means Tony, is your job has just gotten harder. You must now educate yourself as to which can be double tapped.
Roger
Mike, I think if we are talking about stranded it would definatly need to be evaluated. My reference to the screw goes back to my engine building days as far as stretching threads either in the seat or on the bolt. I allways thought that was hearsay too.
bhp, any mechanical connection will change over time. When retorqueing, you would need to go back to the same conditions (ambient temps for example) that were present the day it was first done to get an acurate feel of how much change occured.
Unfortunately, "expense" is a driving factor in competitive bidding. I know you are looking at a single installation, but let's say you have bid a subdivision, you have to look at savings that would be allowed by code. Also
I agree
Now let's look back at Tony's question. Yes, by the code, if the breaker is listed for two wires it is not a violation, and if it was written up Tony is wrong.
What this means Tony, is your job has just gotten harder. You must now educate yourself as to which can be double tapped.
Roger
charlie tuna
Senior Member
- Location
- Florida
Re: Double tapping on a circuit breaker
tonymazz--- the list you posted concerning home inspections is a joke --- right?
concerning two wires on circuit breakers -- iv'e been in the electrical system infrared inspection business since 1989 and have never come across a breaker overheated due to two wires on a breaker. we see breakers that are overloaded, or that have internal problems--meaning high temp. with little load, a breaker running with a 80 or 90 per cent load should be hot! the two wire thing is an electrical "common sense" issue. there's no difference if two wires are properly torqued under the breaker's terminal screw or a pigtailed with a single wire to the breaker. the load applied to the breaker is the main issue. is there really a problem doubling up the receptacle located under the panel with the corridor receptacle circuit in an office building to gain a circuit for a copier?
tonymazz--- the list you posted concerning home inspections is a joke --- right?
concerning two wires on circuit breakers -- iv'e been in the electrical system infrared inspection business since 1989 and have never come across a breaker overheated due to two wires on a breaker. we see breakers that are overloaded, or that have internal problems--meaning high temp. with little load, a breaker running with a 80 or 90 per cent load should be hot! the two wire thing is an electrical "common sense" issue. there's no difference if two wires are properly torqued under the breaker's terminal screw or a pigtailed with a single wire to the breaker. the load applied to the breaker is the main issue. is there really a problem doubling up the receptacle located under the panel with the corridor receptacle circuit in an office building to gain a circuit for a copier?
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