225.32 question

[ceb58]

I am having a hard time wrapping my head around part of 225.32. The reason being is a discussion I had/am having about a generator install.
The discussion is about the gen. set disconnect. My point of view is the breaker on the gen.set doesn't meet 445.18 or 225.36 and I think that there is a large group here that concur. That said 225.32 says that the disconnect can be located inside or outside the building or structure it serves. But it also goes on to say it shall be in a readily accessible location nearest the point of entry. The nearest point of entry is what I am scratching my head about. I know what 230.70 A 1 states as to service conductors and I agree with having the least amount of unprotected conductors entering the building. But 225 covers branch circ. and feeders. I cannot see the point of having the "nearest point of entry" wording for the feeders. The feeders are protected by the OCP on the gen.set even though it may not be considered the disconnecting means the feeder conductors are still protected.
Here is a set up to illustrate what I am speaking of.
If you were to mount a SE rated ATS it would need to be located at the closest point of entry to the service conductors to comply with 230.70 A 1. Then you brought in the feeders from the gen set and because of location your run was 20 ft inside the building. By the wording of 225.32 you could be failed on the install. The only course would be to add another disconnect at the point of entry of the feeders which would be redundant. Dose this make sense or has the pain killers for my back kicked in yet?

 

[Smart $]

Yes, one can consider it redundant... but rules regarding this matter are not made to be broken

Moreover, adding another disconnecting means is not the only solution (though it may well be both the most practical and practicable).

 

[suemarkp]

The state of Washington fixed that with this local code mod: WAC 296-46B-225 032 (2) The building disconnecting means required by NEC 225.32 must be provided to disconnect all ungrounded conductors that supply or pass through a building or structure per the requirements of NEC 225.32 (except for Exceptions 1, 2, 3, or 4) in accordance with subsection (a) or (b) of this subsection.

(a) Outside location: Except for an outdoor generator set described in a NEC 700, 701, or 702 system, where the feeder disconnecting means is installed outside a building or structure,...

(b) Inside location: The feeder disconnecting means may be installed anywhere inside a building or structure when there is a feeder disconnecting means, located elsewhere on the premises, with overcurrent protection sized for the feeder conductors.

Perhaps you have local code mods?

 

[jwelectric]

If there is a service rated transfer switch and both the service and the generator are supplied to the transfer switch then the transfer switch would be the disconnecting means outlined in both 230 and 225.

If either of these conductors entered the building before hitting the transfer switch then an additional disconnect would be required either outside or inside nearest the point of entrance of the conductors. In this case the service overcurrent devices would be required to be an integral part of the service disconnecting means or located immediately adjacent thereto.

If in your case the generator conductors enter the building 20 feet before hitting the transfer switch then a disconnect would be required to be installed as outlined in 225.32.

The disconnect located on the generator as outlined in 445.18 would be required to be rated as a service disconnect as outlined in 225.36 and must also be visible from the building with all doors and panels closed as outlined in 702.11.

On a side note; A lot of generators come with a disconnect that looks like a breaker that has an amperage rating marked on the handle. These are not overcurrent devices. The disconnecting means (this thing that looks like a breaker) is labeled at its current limitations not its overcurrent capabilities. These are not breakers!! They do not open in the event of a short circuit, ground fault or overcurrent situations. They are disconnects only.

 

[augie47]

ceb58, In you post, you mentioned Art 225 and Art 445. When looking at this you do need to take Mike's reference to 702.11 into account although I've seen few installs where the generator breaker fits the bill.

 

[Dennis Alwon]

If there is a service rated transfer switch and both the service and the generator are supplied to the transfer switch then the transfer switch would be the disconnecting means outlined in both 230 and 225.

If either of these conductors entered the building before hitting the transfer switch then an additional disconnect would be required either outside or inside nearest the point of entrance of the conductors. In this case the service overcurrent devices would be required to be an integral part of the service disconnecting means or located immediately adjacent thereto.

If in your case the generator conductors enter the building 20 feet before hitting the transfer switch then a disconnect would be required to be installed as outlined in 225.32.

The disconnect located on the generator as outlined in 445.18 would be required to be rated as a service disconnect as outlined in 225.36 and must also be visible from the building with all doors and panels closed as outlined in 702.11.

On a side note; A lot of generators come with a disconnect that looks like a breaker that has an amperage rating marked on the handle. These are not overcurrent devices. The disconnecting means (this thing that looks like a breaker) is labeled at its current limitations not its overcurrent capabilities. These are not breakers!! They do not open in the event of a short circuit, ground fault or overcurrent situations. They are disconnects only.

Nice post Mike. Hope all is well.

 

[ceb58]

ceb58, In you post, you mentioned Art 225 and Art 445. When looking at this you do need to take Mike's reference to 702.11 into account although I've seen few installs where the generator breaker fits the bill.

Gus, Yes there are installs that fit 702.11 if the unit complies with 225.36 which leads back to 225.31.
My point to the OP was the wording in 225.32 for the feeders. In particular the wording that requires the disconnect at the nearest point of entry. I know 230.70 states this for service conductors as they are unprotected. What I am looking for is an opinion as to why feeder conductors would need the same wording. Example:
#1 If you have a MDP in a basement you can install SER cable on a OCPD then run 60 ft to the second floor to a MLO panel and your OK.
#2 A gen set outside SER is installed on OCPD it comes into building then runs 20ft inside to a SE rated ATS. But by the wording of 225.32 a disconnect would be requried outside or inside at closest point of entry.

The only difference between example 1 & 2 is that 1 originates in the building and doesn't leave the building. But in both cases the feeder is protected by OCP. Why would entering the building make a difference for a feeder?

 

[Smart $]

... Why would entering the building make a difference for a feeder?

Add a third example, feeder to a second structure, then compare...

 

[jwelectric]

Maybe it would be easier to explain this if I could get you to explain something to me.
If you can explain to me why I would need a disconnect at things such as heat pumps, air conditioners, air handlers, motors, and the list go on and on it would help me to explain why the disconnect is required at a remote building.

We all know that those conductors have branch circuit protection and a means to disconnect current from the appliance at the panel so why is there a need for a disconnect for these items within sight of the appliance?

 

[ceb58]

Maybe it would be easier to explain this if I could get you to explain something to me.
If you can explain to me why I would need a disconnect at things such as heat pumps, air conditioners, air handlers, motors, and the list go on and on it would help me to explain why the disconnect is required at a remote building.

We all know that those conductors have branch circuit protection and a means to disconnect current from the appliance at the panel so why is there a need for a disconnect for these items within sight of the appliance?

Mike, I appreciate your answers and I know and see why for items you listed on branch circ. the requirements for disconnecting is needed.
My only point was in the hypothetical situation of the feeders coming into a building and running 20 ft to a SE rated ATS was the need for redundant disconnecting. In a real life situation the problem would/could be solved by the wording in 225.32 " closest point of entry" Same as 230.70 for service conductors.
By the way I have went back and reread your post on this subject from Sept. 08 very good info keep up the good work.

 

[jwelectric]

As a code enforcement official I would in all likelihood for a scenario such as you have posted pass the installation without requiring an additional disconnect if the line of sight from the point of entry to the transfer switch was unobstructed.

The wording of the NEC is what I teach and the letter of the NEC without exception would require a disconnect.