Author Topic: electrical code question  (Read 9368 times)

Spork

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electrical code question
« on: January 26, 2015, 02:20:58 PM »

I have a tendency to learn bits and pieces of electrical code by observing how previous electricians have done things (and google).  Yes, I know this makes my knowledge a little incomplete -- and makes it dependent on the perfect work of people before me.

I've currently got a hard wired 220v bath heater on a 2 pole 15amp circuit.  The heater is 2000w/9.1 amp heater.

Can I add a second 220v hard wired heater 475w/2.1amp to that same circuit? 

This is clearly under 15 amps, but I have some vague recollection of reading about what percentage of capacity is legal and some vague recollection that there may be different rules for hard wired 220v devices.   My google-fu is just not working finding this.

I've got plenty of space in the panel to add another circuit if I need to.

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Re: electrical code question
« Reply #1 on: January 26, 2015, 03:49:55 PM »
My guess is that you are close enough to not make it a good idea as with both of them running you would be at a higher percentage of the circuit breaker (15 amps) than you would want for continuous duty (Watts = volts * amps). The code requirement is something like 80% of the breaker rating (so 12 amps in your 15amp circuit as a continuous duty ceiling). This also assumes the correct gauge wire was used in the circuit. The problem you are trying to avoid is running too much through the wires and having them overheat and start a fire.

If you will be doing a number of these types of projects, or general electrical work, I suggest buying an electrical code compliance flip book. They have tables for comparing loads to wire size and breakers for compliance, in addition to many of the other little questions that come up.

caveat: I'm not an electrician, so I encourage you to take this with a grain of salt.

Glenstache

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Re: electrical code question
« Reply #2 on: January 26, 2015, 03:51:15 PM »

cn1ght

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Re: electrical code question
« Reply #3 on: January 26, 2015, 03:53:51 PM »
I would strongly suggest waiting until someone else confirms/denies this despite my background...

Circuit breakers should be rated for 125% of the total connected load.
9.1A + 2.1A = 11.2A
11.2A * 1.25 = 14A

I am not personally familiar with 220V hard-wired having anything specific, however I also deal with the industrial side not residential.  I also left my codebook at work...  Also, I really would not trust me without someone else verifying.  With that ("that" refers to yes I think you can add this load to the circuit) being said: heaters and motors have large in-rush currents.  "Large" meaning 6X is not uncommon, and is on the low end.  The annoying answer is you would have to look at the coordination curves of the breaker in question and see if the breaker will trip before the in-rush current settles or not.  The practical answer is that there is a very high chance that the in-rush current is not going to trip the breaker.

DarinC

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Re: electrical code question
« Reply #4 on: January 26, 2015, 11:27:42 PM »
What cn1ght said.

http://ecmweb.com/basics/sizing-circuit-breaker

It looks like most standard CBs are rated at 80%, and a 100%-rated CB is naturally rated at 100%.

I'm not sure what the max inrush/startup current is for the 100% rated CB, but if the load is noncontinuous you can apparently use 100% of the standard CB rating.

Spork

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Re: electrical code question
« Reply #5 on: January 27, 2015, 07:37:22 AM »

If you will be doing a number of these types of projects, or general electrical work, I suggest buying an electrical code compliance flip book. They have tables for comparing loads to wire size and breakers for compliance, in addition to many of the other little questions that come up.


This is probably a good suggestion.  In the past I had an electrician friend that worked just down the hall I'd bounce this off of.

bzzzt

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Re: electrical code question
« Reply #6 on: January 27, 2015, 10:45:16 AM »
Assuming a purely resistive load (coil heater/strip heater), you should be fine. Most branch circuits should only be loaded to 80% of the breaker rating, so keep it under 12A. Only thing that may trip you up is if either heater has a fan and you see in-rush current. Even so, for a small fan, it shouldn't see much in-rush.

Also, make sure that is the only device on that breaker. Often times in residential, people add things to the circuit and don't mark the panel.

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Re: electrical code question
« Reply #7 on: January 27, 2015, 12:28:00 PM »
Assuming a purely resistive load (coil heater/strip heater), you should be fine. Most branch circuits should only be loaded to 80% of the breaker rating, so keep it under 12A. Only thing that may trip you up is if either heater has a fan and you see in-rush current. Even so, for a small fan, it shouldn't see much in-rush.

Also, make sure that is the only device on that breaker. Often times in residential, people add things to the circuit and don't mark the panel.

I know the original heater is the only device... I installed that one a while back.  The existing heater has a tiny (ineffective) fan.  It pretty much only runs when we're showering.  The new low amp heater runs on convection and will probably run quite often.

bzzzt

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Re: electrical code question
« Reply #8 on: January 27, 2015, 01:14:06 PM »
You'll be fine unless it's extremely far from the panel. I am an electrician.

Spork

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Re: electrical code question
« Reply #9 on: January 28, 2015, 03:35:37 PM »
You'll be fine unless it's extremely far from the panel. I am an electrician.

Thanks!   It's very close.  I'd be wild ass guessing, but probably 25 feet of wire or so by the time I drag it.

ImCheap

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Re: electrical code question
« Reply #10 on: January 29, 2015, 08:18:31 AM »
This is the steps of how I would look at it based on the 2014 National Electric Code (NEC)

NEC Article 100 defines continuous load as 3 hours or more.

NEC 424.3(B) notes fixed electric heat to be considered continuous load.

NEC 215.2(A)(1)(a) is where you will find the conductor shall be sized at 125% continuous loads.

NEC 220.51 covers fixed electric space heating, space heating loads shall be calculated at 100%.

(9.1 Amp + 2.1Amps) 125% = 14Amps.

You have one amp left to spare. Just be sure you are using the total load of the heater, some people will look at the heater as a 500watt heater but forget to add the motor fan load if they have one.

You will be fine, Im not a big fan of running heavier continuous loads to the max and would use #12 wire if I was starting from scratch.  The dollars saved from #14 and #12 is peanuts compared to the rest of the construction of a house.

Edit: I should have noted the difference between art. 220 and 215 as that tends to hang up a few people. 220 is for calculating the load while 215 is calculating the feeder ampacity.
« Last Edit: January 29, 2015, 08:24:44 AM by ImCheap »

Spork

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Re: electrical code question
« Reply #11 on: January 30, 2015, 10:02:05 AM »

You will be fine, Im not a big fan of running heavier continuous loads to the max and would use #12 wire if I was starting from scratch.  The dollars saved from #14 and #12 is peanuts compared to the rest of the construction of a house.


The 9amp heater was run with #12 for that reason.
The 2amp will be a home run back to the circuit breaker with #14 since it is such a tiny draw.

ImCheap

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Re: electrical code question
« Reply #12 on: February 02, 2015, 07:52:37 AM »

You will be fine, Im not a big fan of running heavier continuous loads to the max and would use #12 wire if I was starting from scratch.  The dollars saved from #14 and #12 is peanuts compared to the rest of the construction of a house.



The 9amp heater was run with #12 for that reason.
The 2amp will be a home run back to the circuit breaker with #14 since it is such a tiny draw.

Than no big deal at all, I missed that part.

Do you have to run all the way back to the breaker? No opportunity to hit the circuit closer?

You may want to run #12 at this point anyway if you are going all the way back, the only reason I say this is to future proof it a little. You have an existing #12 that serves the 9amp load, if for whatever reason you need to bump that or you wind up a little over with the new load you can't toss in a 20amp breaker unless you upgrade the #14 or pull it off.

In the residential world keep the same gauge wire throughout the same circuit is wise and more so common.  In commercial you start to see more tap rules etc. being used but that's even becoming old hat in many ways. I may use a tap rule in a process plant if I'm pushed into a corner.

paddedhat

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Re: electrical code question
« Reply #13 on: February 02, 2015, 09:15:03 AM »
The last post is correct. Technically it is acceptable to use #14 in this case, but it isn't something that most pros. would do, and it leads to a pretty big red flag for anybody inspecting, or working on, the installation at a later date. Personally, I would use the #12 and spend the $9 for a 20 amp 2 pole breaker. Then the installation is more in line with accepted practice, and you have plenty of extra capacity.

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Re: electrical code question
« Reply #14 on: February 02, 2015, 03:25:07 PM »

Well, too late... already ran it this weekend...  (I can always rework it if that's really needed.)

The home run was much easier than tying into the existing... It's really close to the panel.  These 2 heaters are sort of in opposite corners of the house.

I guess I could have spliced into the run for the first heater... but where I'd have to splice in is in the attic right above the panel where there is a crap ton of wiring.  It just seemed neater to push it the extra 6 or so feet back into the panel.

ImCheap

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Re: electrical code question
« Reply #15 on: February 03, 2015, 10:02:20 AM »
It will be fine Spork, just let it buck. A little unorthodox but I have seen much stranger things than this.

MrFrugalChicago

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Re: electrical code question
« Reply #16 on: February 04, 2015, 10:05:57 AM »
The last post is correct. Technically it is acceptable to use #14 in this case, but it isn't something that most pros. would do, and it leads to a pretty big red flag for anybody inspecting, or working on, the installation at a later date. Personally, I would use the #12 and spend the $9 for a 20 amp 2 pole breaker. Then the installation is more in line with accepted practice, and you have plenty of extra capacity.

Ditto, I would do it with #12 and a 20 amp breaker. Once I get past 10 amps of planned load, I start looking for #12 and 20 amp breaker. I may err on the side of overkill, but it helps me sleep at night.

newideas2013

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Re: electrical code question
« Reply #17 on: February 04, 2015, 08:09:32 PM »

Well, too late... already ran it this weekend...  (I can always rework it if that's really needed.)

The home run was much easier than tying into the existing... It's really close to the panel.  These 2 heaters are sort of in opposite corners of the house.

I guess I could have spliced into the run for the first heater... but where I'd have to splice in is in the attic right above the panel where there is a crap ton of wiring.  It just seemed neater to push it the extra 6 or so feet back into the panel.

How far is your total run? Feet wise? We have code rules in Canada we can't exceed 3% volt drop in a circuit and long runs we frequently boost wire sizes. It's not uncommon for us on 900ft runs in conduit with derating rules to run #6 to back fence plugs for block heaters.

If it's under say 80ft and you're at ~11.2 amps you're fine in my books, I can't remember whether we can't load our circuits past 80% or if that's only for continuous loads. Still the general saying of guys I work with is loads should be 12 amps on a 15 amp circuit, and if the runs were so long you were seeing >3% volt drop you'd have to upsize to #12 or larger anyway.

ImCheap

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Re: electrical code question
« Reply #18 on: February 05, 2015, 07:33:30 AM »

Well, too late... already ran it this weekend...  (I can always rework it if that's really needed.)

The home run was much easier than tying into the existing... It's really close to the panel.  These 2 heaters are sort of in opposite corners of the house.

I guess I could have spliced into the run for the first heater... but where I'd have to splice in is in the attic right above the panel where there is a crap ton of wiring.  It just seemed neater to push it the extra 6 or so feet back into the panel.

How far is your total run? Feet wise? We have code rules in Canada we can't exceed 3% volt drop in a circuit and long runs we frequently boost wire sizes. It's not uncommon for us on 900ft runs in conduit with derating rules to run #6 to back fence plugs for block heaters.

If it's under say 80ft and you're at ~11.2 amps you're fine in my books, I can't remember whether we can't load our circuits past 80% or if that's only for continuous loads. Still the general saying of guys I work with is loads should be 12 amps on a 15 amp circuit, and if the runs were so long you were seeing >3% volt drop you'd have to upsize to #12 or larger anyway.

In the US we have it listed as Fine Print Note (FPN) in the NEC, its suggested but not required.

Branch Circuits This FPN recommends that branch circuit conductors be sized to prevent a maximum voltage drop of 3%. The maximum total voltage drop for a combination of both branch circuit and feeder should not exceed 5%. [210-19(a) FPN No. 4]

Feeders This FPN recommends that feeder conductors be sized to prevent a maximum voltage drop of 3%. The maximum total voltage drop for a combination of both branch circuit and feeder should not exceed 5%. [215-2(d) FPN No. 2]

Section 110-3(b) however notes that equipment be installed in accordance with the manufactures requirements, so they somewhat hang you anyway as most equipment is rated to run within some voltage range.  I don't recall ever being pressed on this issue however.

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Re: electrical code question
« Reply #19 on: February 05, 2015, 03:05:41 PM »

Well, too late... already ran it this weekend...  (I can always rework it if that's really needed.)

The home run was much easier than tying into the existing... It's really close to the panel.  These 2 heaters are sort of in opposite corners of the house.

I guess I could have spliced into the run for the first heater... but where I'd have to splice in is in the attic right above the panel where there is a crap ton of wiring.  It just seemed neater to push it the extra 6 or so feet back into the panel.

How far is your total run? Feet wise? We have code rules in Canada we can't exceed 3% volt drop in a circuit and long runs we frequently boost wire sizes. It's not uncommon for us on 900ft runs in conduit with derating rules to run #6 to back fence plugs for block heaters.

If it's under say 80ft and you're at ~11.2 amps you're fine in my books, I can't remember whether we can't load our circuits past 80% or if that's only for continuous loads. Still the general saying of guys I work with is loads should be 12 amps on a 15 amp circuit, and if the runs were so long you were seeing >3% volt drop you'd have to upsize to #12 or larger anyway.

I'm not sure how you measure here since I was unconventional and made 2 home runs.

Panel -> heater1 -- about 60 ft.  This is the 9 amp heater that runs 1x a day.  Run with #12.
Panel -> heater2 -- about 40 ft.  This is the 2 amp heater that runs off and on all the time.  Run with #14.  (I think I originally stated this was 25 ft.  It was probably closer to 40.)

So... on the whole, its 100ft, but they are both home runs to the panel.

MrFrugalChicago

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Re: electrical code question
« Reply #20 on: February 05, 2015, 04:04:59 PM »

Panel -> heater1 -- about 60 ft.  This is the 9 amp heater that runs 1x a day.  Run with #12.
Panel -> heater2 -- about 40 ft.  This is the 2 amp heater that runs off and on all the time.  Run with #14.  (I think I originally stated this was 25 ft.  It was probably closer to 40.)

So... on the whole, its 100ft, but they are both home runs to the panel.

Both tie into a single 15 amp breaker?

Would splitting them off into a 20 amp breaker for the #12 and keep the #14 on a separate existing 15 amp breaker be out of the question?

paddedhat

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Re: electrical code question
« Reply #21 on: February 05, 2015, 06:44:19 PM »

Panel -> heater1 -- about 60 ft.  This is the 9 amp heater that runs 1x a day.  Run with #12.
Panel -> heater2 -- about 40 ft.  This is the 2 amp heater that runs off and on all the time.  Run with #14.  (I think I originally stated this was 25 ft.  It was probably closer to 40.)

So... on the whole, its 100ft, but they are both home runs to the panel.

Both tie into a single 15 amp breaker?

Would splitting them off into a 20 amp breaker for the #12 and keep the #14 on a separate existing 15 amp breaker be out of the question?

What would the point be? The load is well under 80% of the breaker rating, the #12 is oversized for the branch circuit and breaker rating, and splitting anything would only eat up two more available panel spaces for no logical reason.

newideas2013

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Re: electrical code question
« Reply #22 on: February 05, 2015, 09:44:22 PM »
Pretty sure he said 240V double pole breaker. A bit confused on how you ran it.

If you had large tub heater, 240V you ran #12 to a ~9a load (no neutral) it's just straight 240. You wired another ~3A heater in parallel, should be no return/home run no? Just #14 from the tub heater to new heater? Maybe I'm misunderstanding. Anyway..probably fine. Idk I wouldn't do anything without inspection anyways but I don't know the rules on where you live.

edit: I think I see now... you ran two home runs off the same 2 pole breaker? One set of #12s off in one direction to tub heater (60ft) and one set of #14s to new heater in a different direction (40ft)? If that's the case I would research more about whether double tapping breakers is allowed. I've heard it's a no, but don't have a CEC code reference for that, let alone US NEC, and a very quick google there seemed to be debate about certain manufacturers. We never ever do it in new installs at my company, ever, but as far as code.. I don't know.

In my head I see 2 ways to wire this.. 2 home runs to panel, ie: each being their own seperate 240v circuit, or they're wired in parallel. If 2 home runs to panel I'd just use 2 different 2 pole breakers. If I was a HO doing my own electrical work and didn't have much breaker space left in my main panel I'd install a sub panel somewhere convenient. Just my 2c anyways :)
« Last Edit: February 05, 2015, 09:53:15 PM by newideas2013 »

MrFrugalChicago

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Re: electrical code question
« Reply #23 on: February 06, 2015, 06:49:27 AM »

Panel -> heater1 -- about 60 ft.  This is the 9 amp heater that runs 1x a day.  Run with #12.
Panel -> heater2 -- about 40 ft.  This is the 2 amp heater that runs off and on all the time.  Run with #14.  (I think I originally stated this was 25 ft.  It was probably closer to 40.)

So... on the whole, its 100ft, but they are both home runs to the panel.

Both tie into a single 15 amp breaker?

Would splitting them off into a 20 amp breaker for the #12 and keep the #14 on a separate existing 15 amp breaker be out of the question?

What would the point be? The load is well under 80% of the breaker rating, the #12 is oversized for the branch circuit and breaker rating, and splitting anything would only eat up two more available panel spaces for no logical reason.

If I know anything about how most people do electrical.. these are not the only 2 things on the circuit. Maybe a few lights. Maybe a few empty outlets. Then someone plugs in a vacuum and BOOM.

Circuits are "cheap", no reason to be stingy. Yes you need a big enough panel, but once there adding another one is nothing.

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Re: electrical code question
« Reply #24 on: February 06, 2015, 06:51:10 AM »
If I was a HO doing my own electrical work and didn't have much breaker space left in my main panel I'd install a sub panel somewhere convenient. Just my 2c anyways :)

Why not just tandem breaker it? Legit way to wire 2 loads into 1 breaker slot.

http://www.homedepot.com/p/Square-D-Homeline-2-20-Amp-Single-Pole-Tandem-Circuit-Breaker-HOMT2020CP/202353308?N=5yc1vZbm0f

Spork

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Re: electrical code question
« Reply #25 on: February 06, 2015, 10:53:31 AM »


If I know anything about how most people do electrical.. these are not the only 2 things on the circuit. Maybe a few lights. Maybe a few empty outlets. Then someone plugs in a vacuum and BOOM.

Circuits are "cheap", no reason to be stingy. Yes you need a big enough panel, but once there adding another one is nothing.

These are the only things on the breaker.  I don't have any 240v lights. ;)

paddedhat

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Re: electrical code question
« Reply #26 on: February 06, 2015, 06:27:52 PM »
Pretty sure he said 240V double pole breaker.
edit: I think I see now... you ran two home runs off the same 2 pole breaker? One set of #12s off in one direction to tub heater (60ft) and one set of #14s to new heater in a different direction (40ft)? If that's the case I would research more about whether double tapping breakers is allowed. I've heard it's a no, but don't have a CEC code reference for that, let alone US NEC, and a very quick google there seemed to be debate about certain manufacturers. We never ever do it in new installs at my company, ever, but as far as code.. I don't know.


 I have asked this question to inspectors, and the answer I got was it's fine if it's acceptable to the breaker manufacturer. Now most breakers I use are clearly designed to clamp to conductors, so I never really had an issue. If it was an issue, it's also perfectly legal to make splices in the panel, as the wireway adjacent the breakers is considered a trough. So, two wire nuts and a short single tail to the breaker would pretty much wrap this case up.

Spork

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Re: electrical code question
« Reply #27 on: February 06, 2015, 07:10:09 PM »
Pretty sure he said 240V double pole breaker.
edit: I think I see now... you ran two home runs off the same 2 pole breaker? One set of #12s off in one direction to tub heater (60ft) and one set of #14s to new heater in a different direction (40ft)? If that's the case I would research more about whether double tapping breakers is allowed. I've heard it's a no, but don't have a CEC code reference for that, let alone US NEC, and a very quick google there seemed to be debate about certain manufacturers. We never ever do it in new installs at my company, ever, but as far as code.. I don't know.


 I have asked this question to inspectors, and the answer I got was it's fine if it's acceptable to the breaker manufacturer. Now most breakers I use are clearly designed to clamp to conductors, so I never really had an issue. If it was an issue, it's also perfectly legal to make splices in the panel, as the wireway adjacent the breakers is considered a trough. So, two wire nuts and a short single tail to the breaker would pretty much wrap this case up.

It would be easy to plop a work box in the attic, too.  I guess I was just too uninformed to realize that was the norm. 

I saw two obvious clamps on the breaker and thought it more normal.   

If I go back and mess with it again... I'll probably pull the drop back and splice it above.  I have a limited amount of conduit from attic to panel.  If I am going to splice, I'll free up that conduit.

paddedhat

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Re: electrical code question
« Reply #28 on: February 06, 2015, 07:13:45 PM »
IMHO, I wouldn't do a damn thing at this point. No codes were violated, nobody got hurt, you did the job safely.................time for a new adventure.

Spork

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Re: electrical code question
« Reply #29 on: February 06, 2015, 08:45:18 PM »
IMHO, I wouldn't do a damn thing at this point. No codes were violated, nobody got hurt, you did the job safely.................time for a new adventure.

Thanks... I'll try to let it go.   I'm outside of city enforceable "code" anyway... I just want it to be "right."

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Re: electrical code question
« Reply #30 on: February 07, 2015, 05:59:36 AM »
Yikes. I guess it's your house, but double tapping or splicing in the panel are big red flags here and will not pass inspection. Just wanted to post that up so people who search later don't make the assumption that it's OK everywhere.

paddedhat

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Re: electrical code question
« Reply #31 on: February 07, 2015, 06:39:12 AM »
Yikes. I guess it's your house, but double tapping or splicing in the panel are big red flags here and will not pass inspection. Just wanted to post that up so people who search later don't make the assumption that it's OK everywhere.


Q.  Can I make a splice within a panel?


As. Yes. Section 373-8 states that enclosures for overcurrent devices shall not be used as a junction box or raceways, unless adequate space is provided. Conductors inside a panelboard shall not fill the wiring space at any cross section to more than 40 percent, and splices and taps shall not fill the wiring space at any cross section to more than 75 percent, Figure 1.


 Q. Is it permissible to terminate two circuits on a single circuit breaker?

A. Sometimes. According to 110-3(b) "listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling" and 110-14(a) states "terminals for more than one conductor shall be so identified".

The only time two wires can be installed under a single screw or lug is when the terminal is identified for this purpose. Circuit breakers rated not more than 30 amperes are often identified for the termination of two conductors. This can be verified by reviewing the circuit breaker manufacture's catalog.





All highlighted information is from Mike Holt, a noted educator and authority of the prevailing US electrical code, the NEC. I would add that I have not seen, or used any modern, commonly available circuit breaker, rated from 15 through 30 Amps, that WAS NOT designed for used with two conductors per terminal, in at least a decade.


Now lets turn your response upside down.  The vast majority of readers here, that are located in areas that are NOT in a horrendously corrupt location, such as Chicago or NYC, will have no issue with spices, or double taps in a residential panel. Much of the LOCAL codes is these corrupt areas are based on wasting time and material, while requiring a much higher skill level than reality dictates, to get the job done. For example, metal conduit in residential work, cast iron drain lines, copper supply lines in plumbing, etc....This is a century old practice and a direct result of the corrupt relationship between the trade unions and the local authorities. If you're thinking that this claim is the ranting of a union hater, guess again, I am an IBEW electrician. If you are continuously doing work in one of these areas, and "don't get out much" it can be a real eye opener to see that a hell of a lot of what you are taught to view as serious issues, is in fact, SOP, and perfectly safe in the real world.

The worst example of this that I ever encountered was getting a call from one of my new home customers who had toured their partially completed home with the family, and needed to see me immediately, since their uncle warned them that their home was wired in a dangerous and incompetent manner. When I got to the house, my first question was, "let me guess, your uncle is a union electrician from NYC?" They were a bit freaked out, but answered yes. I then explained that he works in one of the most corrupt places in the country, and the code there requires that all residential work be installed in metal conduit. Not that it might arguably make a better job, but it wasn't required, not something you see in 99.999% of all new homes, and would triple the price of the electrical installation.

As for the "Yikes, it's your home" Yep, it sure is. One with no code violations, or safety issues.

Spork

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Re: electrical code question
« Reply #32 on: February 07, 2015, 08:55:00 AM »

My panel is Square D (residential line) ... It clearly has 2 ears on each lug and clearly had  2 #10-#14 on the side.   I knew enough to look for that.  I just didn't know double tapping was any sort of red flag. 

From the majority opinion here: I'm inclined to leave it as is.

bzzzt

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Re: electrical code question
« Reply #33 on: February 07, 2015, 10:16:52 AM »
If you're thinking that this claim is the ranting of a union hater, guess again, I am an IBEW electrician. If you are continuously doing work in one of these areas, and "don't get out much" it can be a real eye opener to see that a hell of a lot of what you are taught to view as serious issues, is in fact, SOP, and perfectly safe in the real world.

Well, Brother, I guess we will disagree on best practices. It's always a competition between cost and "good enough". As I said in another thread, that is why I don't like to do much resi work. The utility industry would rather see something done in the best way possible so that it's still functioning correctly long after I'm dead.

As far as the conduit vs. NM debate, I guess it's just a bunch of wasteful guys that can come within a couple thousand of a rope house with a piped house and still have raceways for service in future years. If conduit will triple your cost, you need to teach your hands how to install conduit more efficiently. I worked with a 50 yr old "bungalow buster" who could still put up 800'/day new construction.

As far as corrupt codes, having higher standards than the bare minimum allowable used to be seen as a good thing. An electrical system without access is penny wise and dollar foolish in my opinion, but I guess not everyone can see the value added. Cheap, cheap, cheap on all of the buried systems in the house, but I have to have the $3000 worth of crown molding/wains coating/etc... *shrug*

Sorry for the hijack, Spork.

paddedhat

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Re: electrical code question
« Reply #34 on: February 07, 2015, 12:10:58 PM »
LOL, there are dinosaurs among us. Sorry, but as soon as I hear anybody in the trade (and as time passes, there are very few left) flogging the old, "bunch of rope monkies. no way to add circuits later, blah, blah", like most tradesmen in the 21st, I quickly stop listening. I also have no need to listen to a mechanic morn the loss of split rims and inner tubes.

 The alleged access issue is about as far from reality as it get. Any decent residential tradesmen with the proper skills and tools can run Romex anywhere, anytime, for a fraction of the cost of doing a pipe job. The other reason the whole claim is smoke and mirrors is that  the majority of additional work is to new locations, not in areas where "just adding a wire" will get the job done. In my area it is heavily tilted to new fan installations, hot tubs, pool pumps etc.... You might have a usable junction and pipe capacity to the area, but that's all. If your code jurisdiction is still mired in the corrupt 1940's you're pulling sheetrock to run pipe.

Sorry, but the "higher standards" line doesn't was either. Both issues discussed here, double tapping breakers, and the legitimate use of the wireway in a panel to make splices, have nothing to do with higher standards. They are code sanctioned, standard industry practice that you disapprove of since your still operating half a century in the past. Nothing wrong with that, if you have the time and money to waste. That said, doing it your way, and running conduit in new homes,  is so obscure that it isn't even a rounding error when added to the total of new homes wired. Your being dismissive of industry practice that first became standard between the great wars, and had been doing pretty well ever since. As for it being cost competitive, not even close.

Regarding costs, I'm probably low with the 3X comment. There is much debate on this topic on electrician's forums and it is, as you might imagine, typically a battle between Chicago union electricians and the rest of the first world. Bottom line is that 800' is what is typically expected when slamming 1/2" thin-wall in. Or rough 40-60 man hours to rough in a typical, large home in the 'burbs. Problem with that is that the same job typically takes an electrician and a helper a day an a half with Romex. So roughly 24hrs to complete a rough in, ready for inspection, or 40-60 hours to install conduit, the first step of the job. Once the material costs are accounted for, 3x is going to be typically low, particularly in most market areas, when nobody had done it since Roosevelt was president.