No lights on SABC rule

[mbrooke]

How do you get from here....


to here?


Cognitive dissonance is the only answer.

You know thats normal for me :lol:

But in all seriousness, I have nothing against a few lights being on the SABC. My worry is that if the code did not set a limit (ie 150 VA) then we could see 1,200VA of lighting on them. Picture the typical breakfast where a 900 watt coffee makers is plugged into the same outlet as a 1,500 watt double slot toaster. An extra 1,200 watts will trip the breaker.

And yes I know all toasters are technically double slot, but I have this in mind:

 

[ActionDave]

You know thats normal for me :lol:

But in all seriousness, I have nothing against a few lights being on the SABC.

No thinking person would.

My worry is that if the code did not set a limit (ie 150 VA) then we could see 1,200VA of lighting on them. Picture the typical breakfast where a 900 watt coffee makers is plugged into the same outlet as a 1,500 watt double slot toaster. An extra 1,200 watts will trip the breaker.....

What you describe right there is a design issue, not a safety issue. Every code cycle the NEC goes further down this road because people like you sit on the CMP and say the same thing. It's a shame and I hate it.

 

[480sparky]

There also was a time when there was no NEC, and a time when man hadn't discovered how to use electrical energy.

This rule AFAIK has been in place for quite a while before I ever started wiring. I don't know when it came into effect, but even here where codes were not enforced that much in dwellings until 1990's, you still find 1950 -1960's homes that seemed to sort of follow that rule to some extent (kitchen receptacles typically have no other loads connected to them), so it was either a rule then or people were just smart enough with design concerns to do it that way anyhow.

The 2 SABC rule was introduced into the NEC in 1962.

 

[mbrooke]

No thinking person would.



What you describe right there is a design issue, not a safety issue. Every code cycle the NEC goes further down this road because people like you sit on the CMP and say the same thing. It's a shame and I hate it.

But in some ways it is indeed a safety issue. A circuit that constantly trips on a UL listed toaster is going to invite DIY rigging. I know you think that I sound like one of those CMP members, but keep in mind this rule is well before the NEC became a design manual. Maybe if the code simply said 4,000 or 4,800VA must be reserved for the counter top?

 

[ActionDave]

But in some ways it is indeed a safety issue. A circuit that constantly trips on a UL listed toaster is going to invite DIY rigging. I know you think that I sound like one of those CMP members, but keep in mind this rule is well before the NEC became a design manual. Maybe if the code simply said 4,000 or 4,800VA must be reserved for the counter top?

What your are saying right here is the same way we get to 2017 code requiring floor recpts in meeting rooms. Where does it end? It ends when the NEC stops approving rules that are design issues.

 

[user 100]

The 2 SABC rule was introduced into the NEC in 1959.

FIFY

and those circuits in 1959's 220-3(B) "shall have no other outlets."

While agree with this....
VVVVVVV

And I would argue 99% of the time two SABC with minimal other loads works without issue.

We still need to think about this...

VVVVVVVVVV

Just remember............ there was a time it was permitted. So perhaps you should research why the exclusion was created in the first place.

But in some ways it is indeed a safety issue.

And if you exclude other outlets from the sabcs, then the risks of safety issues goes down, doesn't it?

There is no reason for the code to be changed here. As pointed out by Growler earlier, its not an issue in new const- only in existing stuff.
Someone needs a light hooked up in their older kitchen then they can pay to have it hooked up correctly and not tapped off an sabc. If its difficult (most of the time it really isn't) to get to another circuit for the new light, its only more $$$ for us- and is that a bad thing?

 

[mbrooke]

What your are saying right here is the same way we get to 2017 code requiring floor recpts in meeting rooms. Where does it end? It ends when the NEC stops approving rules that are design issues.

But again, its been that way for some time, which means that there is good reason. Do you really want to move into a home with all the high hats on the SABC?

 

[ActionDave]

But again, its been that way for some time, which means that there is good reason. Do you really want to move into a home with all the high hats on the SABC?

That is irrelevant.

 

[kwired]

Around here up until the 90s the code was loosely enforced. Electricians knew that and wired more for what worked for them and the area. Its very common to find dinning rooms wired in #14 and to have the range hood and under sink light wired off the SABC. DW and Disposer on the same #12. In so far there are zero problems with this.

I will agree with you that code is antiquated. Ie, it was not until recently they took the term rubber out of describing wire insulation.

My only hold back on allow lights on the SABC is that there must be a listed limit. One or two lights are ok, but if 1,200 watts of high hats gets put on the SABC it defeats the intention of the rule.

But in some ways it is indeed a safety issue. A circuit that constantly trips on a UL listed toaster is going to invite DIY rigging. I know you think that I sound like one of those CMP members, but keep in mind this rule is well before the NEC became a design manual. Maybe if the code simply said 4,000 or 4,800VA must be reserved for the counter top?

still a design issue. If you put 1200 watts of lights on your living room circuit it still doesn't leave much other capacity does it? Now make that living room circuit only 15 amps instead of 20 and you restrict it even more. A good designer won't put that much fixed lighting on a circuit that has receptacles with unknown loading, it is just good design practice, but should the circuit become overloaded anyway - we have overcurrent protective devices for a reason.

 

[user 100]

But again, its been that way for some time, which means that there is good reason. Do you really want to move into a home with all the high hats on the SABC?

ActionDave was ok w/ minimal loads- he wasn't in favor of high hats on SABC's.

 

[mbrooke]

still a design issue. If you put 1200 watts of lights on your living room circuit it still doesn't leave much other capacity does it?

Few living rooms end up with a multitude of 10amp+ appliances. Typical living room only pulls a few amps on average.

Now make that living room circuit only 15 amps instead of 20 and you restrict it even more. A good designer won't put that much fixed lighting on a circuit that has receptacles with unknown loading, it is just good design practice, but should the circuit become overloaded anyway - we have overcurrent protective devices for a reason.

But doesn't code require 3va per foot circuits be evenly distributed among receptacle outlets? To a degree I can see what your saying here- however.

 

[mbrooke]

That is irrelevant.

It is relevant to why code doesn't flat out say the SABC can be used for anything.

ActionDave was ok w/ minimal loads- he wasn't in favor of high hats on SABC's.

As am I. 150-250VA would be ok IMHO. Anything beyond that defeats the purpose of the SABC.

 

[kwired]

Few living rooms end up with a multitude of 10amp+ appliances. Typical living room only pulls a few amps on average.





But doesn't code require 3va per foot circuits be evenly distributed among receptacle outlets? To a degree I can see what your saying here- however.

Some have window AC's or portable electric heaters used in them - that is worse then many kitchen appliances as it is more continuous of a load. Put 1200 watts of lights on a circuit and put in some toast - the toaster only runs for a minute or so and the breaker probably holds even though you were over 20 amps for a bit there.

Put 1200 watts of lights on a circuit and then plug in another 1200 watt heater that won't cycle off for at least half an hour or more and you are going to be in the dark.

Again my own design wouldn't put fixed lights on the kitchen outlet circuits as a general (especially on new construction) rule if NEC allowed it, as I think it is good design decision, but I also still think this is more of a design issue then a safety issue and that NEC shouldn't even address it.

 

[mbrooke]

Some have window AC's or portable electric heaters used in them - that is worse then many kitchen appliances as it is more continuous of a load. Put 1200 watts of lights on a circuit and put in some toast - the toaster only runs for a minute or so and the breaker probably holds even though you were over 20 amps for a bit there.

But that same circuit in conjunction is also supporting a 900 watt coffee maker. Most combinations of small appliances alone load the circuit to 20amps.

Put 1200 watts of lights on a circuit and then plug in another 1200 watt heater that won't cycle off for at least half an hour or more and you are going to be in the dark.

Sure, but with properly designed HVAC that probability goes down. However the odds of a kitchen circuit getting a 20amp combination of counter appliances is almost a given. 1,200= 10amps + 20 amps= 30. A 20amp circuit breaker will easily trip after a few minutes.

Again my own design wouldn't put fixed lights on the kitchen outlet circuits as a general (especially on new construction) rule if NEC allowed it, as I think it is good design decision, but I also still think this is more of a design issue then a safety issue and that NEC shouldn't even address it.

IMHO its both. If you as a code making member knows that a particular circuit will get taxed to the limit 2 to 3 times a day in almost every home in the US, why not impose a limitation on what else can get connected to that?

 

[kwired]

Sure, but with properly designed HVAC that probability goes down.

Are the "Sunheat", "Eden Pure", "Heat Surge" or a few other similar heaters popular in your area?

Don't matter how good the HVAC guy did, those that are sold on them mess the whole system up anyway by using their own "zone heating". I have had customers with new houses and heat pump systems still think their Sunheaters are more efficient, and maybe they are - if you only want to live in one or two rooms of the house.

 

[mbrooke]

Are the "Sunheat", "Eden Pure", "Heat Surge" or a few other similar heaters popular in your area?

Not that I know of. But thats not to say bedrooms (and office cubicles, but thats another story) don't get space heaters.

Don't matter how good the HVAC guy did, those that are sold on them mess the whole system up anyway by using their own "zone heating". I have had customers with new houses and heat pump systems still think their Sunheaters are more efficient, and maybe they are - if you only want to live in one or two rooms of the house.

I get your point, but not every home gets a sun heat- and those that do often have a chance in that resi lighting is not on all at once- or connected to that circuit in bulk.

This is veering off, but FWIW around here builders often did a "general lighting circuit" where the bulk of down stairs lighting got connected to that. So maybe Sun heats weren't showing up in service calls.

 

[kwired]

Not that I know of. But thats not to say bedrooms (and office cubicles, but thats another story) don't get space heaters.




I get your point, but not every home gets a sun heat- and those that do often have a chance in that resi lighting is not on all at once- or connected to that circuit in bulk.

This is veering off, but FWIW around here builders often did a "general lighting circuit" where the bulk of down stairs lighting got connected to that. So maybe Sun heats weren't showing up in service calls.

That is what I typically do as well and why the rule sort of doesn't really matter to me anyway. I usually put all lighting on 15 amp circuits and nearly all receptacle outlets on 20 amp circuits. Sometimes maybe a bathroom light on the 20 amp bath circuit just out of convenience or maybe fan/light over tub is simpler to GFCI protect if needed that way.

 

[ActionDave]

But that same circuit in conjunction is also supporting a 900 watt coffee maker. Most combinations of small appliances alone load the circuit to 20amps.






Sure, but with properly designed HVAC that probability goes down. However the odds of a kitchen circuit getting a 20amp combination of counter appliances is almost a given. 1,200= 10amps + 20 amps= 30. A 20amp circuit breaker will easily trip after a few minutes.







IMHO its both. If you as a code making member knows that a particular circuit will get taxed to the limit 2 to 3 times a day in almost every home in the US, why not impose a limitation on what else can get connected to that?

My house, my wiring, my design- upstairs bedroom has one 15A circuit, in the summer a window shaker A/C gets plugged in, one time my daughter tried to use a blow dryer on her hair and tripped the breaker....A/C down! Blow dryer down! Get me that public input form quick before it gets worse for all of the USA.

 

[mbrooke]

That is what I typically do as well and why the rule sort of doesn't really matter to me anyway. I usually put all lighting on 15 amp circuits and nearly all receptacle outlets on 20 amp circuits. Sometimes maybe a bathroom light on the 20 amp bath circuit just out of convenience or maybe fan/light over tub is simpler to GFCI protect if needed that way.

Why #12? That sucks to work with. But to each his own, I respect that

My house, my wiring, my design- upstairs bedroom has one 15A circuit, in the summer a window shaker A/C gets plugged in, one time my daughter tried to use a blow dryer on her hair and tripped the breaker....A/C down! Blow dryer down! Get me that public input form quick before it gets worse for all of the USA.

No need- because its already been averted in kitchens. Your daughter's hair dryer use is not 2-3 times a day in conjunction with a running AC- and if it was forced to be so- I am willing to bet you would be pulling another circuit.

 

[ActionDave]

I am willing to bet you would be pulling another circuit.

No