NEC 210.25 and NEC 225.30 (A) (3)

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wyboy

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NEC 210.25 says branch circuits shall serve only loads associated with that dwelling unit. NEC 225.30 (A) (3) says additional branch circuits are allowed if from an optional standby system.

I have a dwelling unit that has an Emergency panel inside fed from a generator. The owner wants to bring two branch circuits off that E panel and feed two circuits in his guest house (lights and water heater). Is this allowed?
 
wyboy said:
NEC 210.25 says branch circuits shall serve only loads associated with that dwelling unit. NEC 225.30 (A) (3) says additional branch circuits are allowed if from an optional standby system.

I have a dwelling unit that has an Emergency panel inside fed from a generator. The owner wants to bring two branch circuits off that E panel and feed two circuits in his guest house (lights and water heater). Is this allowed?
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I think that you answered your own question in 225.30 A 3
 
wyboy said:
NEC 210.25 says branch circuits shall serve only loads associated with that dwelling unit. NEC 225.30 (A) (3) says additional branch circuits are allowed if from an optional standby system.

I have a dwelling unit that has an Emergency panel inside fed from a generator. The owner wants to bring two branch circuits off that E panel and feed two circuits in his guest house (lights and water heater). Is this allowed?
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Is the guest house a separate structure or the same structure as the dwelling?
 
wyboy said:
NEC 210.25 says branch circuits shall serve only loads associated with that dwelling unit. NEC 225.30 (A) (3) says additional branch circuits are allowed if from an optional standby system.

I have a dwelling unit that has an Emergency panel inside fed from a generator. The owner wants to bring two branch circuits off that E panel and feed two circuits in his guest house (lights and water heater). Is this allowed?
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Yes, 225.30(A)(4) would permit additional branch circuits to supply a building for the purpose of optional stand-by loads.

Chris
 
My opinion is that this i a violation. Art 702.2 defines optional standby system and I don't believe this qualifies as that.
 
raider1 said:
Yes, 225.30(A)(4) would permit additional branch circuits to supply a building for the purpose of optional stand-by loads.

Chris
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Chris does lighting and a water heater fit the bill
702.2 Definition.
Optional Standby Systems. Those systems intended to supply power to public or private facilities or property where life safety does not depend on the performance of the system. Optional standby systems are intended to supply on-site generated power to selected loads either automatically or manually.
FPN: Optional standby systems are typically installed to provide an alternate source of electric power for such facilities as industrial and commercial buildings, farms, and residences and to serve loads such as heating and refrigeration systems, data processing and communications systems, and industrial processes that, when stopped during any power outage, could cause discomfort, serious interruption of the process, damage to the product or process, or the like.
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Dennis Alwon said:
My opinion is that this i a violation. Art 702.2 defines optional standby system and I don't believe this qualifies as that.
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Why would a lighting circuit and a water heater circuit not be permitted to be on optional stand-by power?

IMHO, optional standby power can supply anything that the owner wants to supply and 225.30(A)(4) would permit additional branch circuits or feeders for optional stand-by power.

Chris
 
raider1 said:
Why would a lighting circuit and a water heater circuit not be permitted to be on optional stand-by power?

IMHO, optional standby power can supply anything that the owner wants to supply and 225.30(A)(4) would permit additional branch circuits or feeders for optional stand-by power.

Chris
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I see the error of my way-- thanks. Here is part of my confusion. If I have a generator that is mounted by the dwelling with the panel on the dwelling, then you are saying I can run a unlimited number of circuits from this panel to this separate structure. :confused:

I was thinking you could only have one feeder or branch circuit from the Generator panel to another panel on this separate structure (Guest house). This would in turn feed the circuits for the optional standby system.
 
Dennis Alwon said:
I see the error of my way-- thanks. Here is part of my confusion. If I have a generator that is mounted by the dwelling with the panel on the dwelling, then you are saying I can run a unlimited number of circuits from this panel to this separate structure. :confused:

I was thinking you could only have one feeder or branch circuit from the Generator panel to another panel on this separate structure (Guest house). This would in turn feed the circuits for the optional standby system.
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Here is the problem with 225.30(A). It says additional feeders or branch circuits shall be permitted to supply the optional standby system.

So with the wording in 225.30(A) I don't see where it limits me to adding only a single branch circuit for optional stand-by power. I think it would be a good idea to limit the additional supplys to a single branch circuit but the wording is not real clear to that point.

Chris
 
raider1 said:
Here is the problem with 225.30(A). It says additional feeders or branch circuits shall be permitted to supply the optional standby system.

So with the wording in 225.30(A) I don't see where it limits me to adding only a single branch circuit for optional stand-by power. I think it would be a good idea to limit the additional supplys to a single branch circuit but the wording is not real clear to that point.

Chris
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And I see that as saying additional branch circuits and feeders because there is more than one condition. So, if you had 2 of the special conditions then I see 2 extra feeders.

You are right, the wording is a bit questionable- at least to me.
 
Chris, I did a lot of questioning of area inspectors and a few CMP members about this question. They all feel as I do that the intent is to limit the number of runs to the separate building. Thus if you had 3 situations that fit into the special conditions afforded in 225.30(A) then you could have 4 feeders or branch circuits. One for the standard power and one for each of the special conditions.

Allowing more than one branch cir. for one special condition goes against the grain of what art. 225.30 wants. Of course, this is our opinions FWIW
 
Dennis Alwon said:
Chris, I did a lot of questioning of area inspectors and a few CMP members about this question. They all feel as I do that the intent is to limit the number of runs to the separate building. Thus if you had 3 situations that fit into the special conditions afforded in 225.30(A) then you could have 4 feeders or branch circuits. One for the standard power and one for each of the special conditions.

Allowing more than one branch cir. for one special condition goes against the grain of what art. 225.30 wants. Of course, this is our opinions FWIW
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I agree that the intent of that section is to limit the number of branch circuits and feeders to 1 with an additional one for the special conditions, but the problem is the wording does not specifically say that.

Chris
 
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