residential generator installations

[iwire]

IMO "Accessible" is a stronger requirement than "Readily Accessible" is.

Something that must be "Accessible" can not be behind a locked door.

Something that must be "Readily Accessible" can be behind a locked door.

225.32

230.70(A)(1)

702.11

All use the term "Readily Accessible" and therefore can be locked.

 

[M. D.]

To my way of thinking, if you have to get past a lock, in order to operate a disconnect, then the disconnect can not be ?reached quickly for operation.? So it?s not readily accessible.

Charlie There are a whole lot of readily acessible disconnects behind locked doors, it is very very commonto do so.

Mike, the way I read it ,the requirement for disconnecting optional Standby systems has been modified by 702.11 in that if one is provided intergral to the generator set and is within 50' and in sight of the building served I am not required to add another one.
If I choose to add another, then the disconnect would need to meet the requirement of 225.31 & 225.36 . If they wanted to they could have refered us back to 225 they did not. Just my opinion.

 

[JohnJ0906]

445.18 Disconnecting Means Required for Generators.
Generators shall be equipped with disconnect(s) by means of which the generator and all protective devices and control apparatus are able to be disconnected entirely from the circuits supplied by the generator except where both of the following conditions apply:
(1) The driving means for the generator can be readily shut down.
(2) The generator is not arranged to operate in parallel with another generator or other source of voltage


What do you all think?

I think for a residential application, both (1) and (2) above apply - at least I always see a gas shut-off at the unit. You may lock the built in breaker, but noone locks the shut off

 

[Jeffnmoe@comcast.net]

Why lock cabinets?

Why lock cabinets?

Because they can. Out of 7 gensets I have inspected,7 have been locked,3 homeowners did not even know where the key was! I am glad to see that my post GENERATED so many response,( ha ,ha ) .I appreciate the input.After reading some of your responses I guess my being told that I sometimes overbuild things might have some valididy!



Thanks for the input to all.

 

[jwelectric]

I am sorry but I am going to have to strongly disagree with you all on this one.

The only thing that I see 702.11 addressing is 225.31 A disconnect for a disconnect.

I don?t see the requirements for outside feeder conductors or any other relief being given in 702.11.
I also see that for this trade for one disconnect for the other it must meet a couple of requirements. One it must be capable of being seen. Second it must be accessible for close approach without having to remove anything.

I don?t see any relief for the required overcurrent protection required for the conductors in 702.11 but if I apply the thinking of what I am reading here the only requirement would be that this generator have a disconnect factory installed and nothing more OR are you saying that 702.11 is relieving only part of the requirements of chapters 1 through 4.

No I am sorry but I think that the requirements found in 225 would still have to be fulfilled meaning that the disconnect in 702.11 would be bound by 225 and 445. This is reinforced through 702.3.

 

[tom baker]

700.9,701.9,and 702.8 state that signage must be placed at service equipment stating that there is an alternate power source and where it is located. As for readily accessible 2005 handbook goes on to say that readily accessible does not preclude of a locked door. Fire fights have an ax I am sure can take care of the lock.

Thanks for posting that sign requirement. I've never seen it enforced.
I don't see anything that prevents a disconnect from being locked on. I do this with outside disconnects for sewer pumps

 

[iwire]

I am sorry but I am going to have to strongly disagree with you all on this one.

The only thing that I see 702.11 addressing is 225.31 A disconnect for a disconnect.

I guess you should take this up with the CMP, they seem to feel differently.

]13-154 Log #2808 NEC-P13

(702-11 (New) )

Final Action: Accept in Principle

TCC Action:

It was the action of the Technical Correlating Committee that this proposal be reconsidered and correlated with the Action on Proposal 4-26a. This action will be considered by the Panel as a public comment.

Submitter: Henry A. Jenkins, Wake County
Recommendation:

Add a new Part IV. Sources of Power to Article 702 for consistency with Articles 700 and 701.

"702.11 Outdoor Generator Sets. Where an outdoor housed generator set is equipped with a readily accessible disconnecting means located within sight of the building or structure supplied, and additional disconnecting means shall not be required where ungrounded conductors enter or pass though the building or structure."

Substantiation:
The new text would permit the disconnecting means for the generator to act as the required disconnecting means for the circuit supplying or passing through a separate building or structure in accordance with 225.31 to be consistent with the same text as provided for generator sets for emergency and legally required standby generators.

Panel Meeting Action: Accept in Principle
Change "…enter…" to "…serve…".

Panel Statement:

See panel action on Proposal 13-124.

Number Eligible to Vote: 14

Affirmative: 14 Ballot Results

And 13-124

13-124 Log #1283 NEC-P13
(700-12(B)(6))
Final Action: Accept in Principle
TCC Action:
It was the action of the Technical Correlating Committee that this proposal be reconsidered and correlated with the Action on
Proposal 4-26a. This action will be considered by the Panel as a public comment.
Submitter: David H. Kendall, Carlon, Lamson & Sessions
Recommendation:
Revise text to read as follows:
(B) Generator Set.
(6) Outdoor Generator Sets. Where an outdoor housed generator set is equipped with a readily accessible
disconnecting means located within sight of the building or structure supplied, an additional disconnecting means
shall not be required where ungrounded conductors enter or pass through the building or structure.
Substantiation:
The new text would permit the disconnecting means for the generator to act as the required disconnecting means for the circuit entering
or passing through a separate building or structure as required by 225.31.
Panel Meeting Action: Accept in Principle
Change "…enter …" to "…serve …".
Panel Statement:
Change is made to proposal to make the wording consistent with text in 225.32.
Number Eligible to Vote: 14
Affirmative: 14 Ballot Results:

Mike you seem obsessed with the requirements in 225.

 

[jwelectric]

I guess you should take this up with the CMP, they seem to feel differently. Mike you seem obsessed with the requirements in 225.

No Bob,
Look again at what I am saying. Look closely at the reference that I made to 225.31 and what the code panel said,

Substantiation: The new text would permit the disconnecting means for the generator to act as the required disconnecting means for the circuit entering or passing through a separate building or structure as required by 225.31.

Nowhere does this statement relieve the other requirements of 225. the only relief is to 225.31 and then only if

an outdoor housed generator set is equipped with a readily accessible disconnecting means located within sight of the building or structure supplied,

For 702.11 to relieve the other sections of 225 then the wording would have to have been,
702.11 Outdoor Generator Sets.
Where an outdoor housed generator set is equipped with a readily accessible disconnecting means located within sight of the building or structure supplied, the requirements in Part II of 225 will not be required where ungrounded conductors serve or pass through the building or structure. The red words are what I changed.

On May 17th at Blue Water Grill 4 Marina Street Wrightsville, NC and again on May 31st at the fire department at 9 Miller Road Skyland (outside of Asheville) NC the NCIAEI will be doing an 8 hour presentation on generators.
Henry A. Jenkins of Wake County NC sits on about half a dozen of the committees for the NCIAEI and works hand in hand with the education committee which is doing these presentations. See NCIAEI for more information.

 

[M. D.]

Mike, for Article 702 to modify it has only to do so, when it come to the requirement for the diconnect it has been modified if your outdoor gen. set is equipped with a disconnect as described , no other is required to be installed by me. I'm not responsible for the process that was followed by the folks who got the thing through whichever testing agencey.

 

[M. D.]

Mike I can't find anything to support what I believe your aguement to be. There is much I can find that supports the idea that a second disconnect is not required if the gen. set meets the requirement of 702.11 .

Please Note: All answers given for the questions below are for discussion purposes ONLY, and are not to be taken as formal interpretations by the Minnesota Chapter IAEI, the Minnesota State Board of Electricity or the employers of the Code Panel members.
The Minnesota Chapter would like to thank the Code Panel members, Michael Buck, Tom Lichtenstein, Mark Earley and Mike Forister for taking time from their busy schedules to participate in this panel, plus the time they have used to research and answer these questions.

35. A permanent generator is installed on the ground outside a building. The generator feeds a computer room and the air conditioning equipment for the building. If the generator is installed inside a locking enclosure, does there have to be a disconnecting means on the exterior of the building for the feeder?

Loads supplied by optional standby systems are loads that if lost can cause physical discomfort, serious interruption of industrial processes, damage to process equipment, or disruption of business. The loads listed in the question seem to fit these requirements.
A generator set typically has an integral circuit breaker that provides overcurrent protection for the generator as well as providing overcurrent protection for properly sized conductors serving the load connected to the generator.
Section 702.11 was added in the 2005 Code which allows a readily accessible disconnecting means on, or part of an outdoor generator set to serve as the disconnecting means required by 225.31 when installed within sight of the building or structure supplied. To be considered within sight the equipment must be visible and not more than 50 feet.
Is the generator set considered readily accessible when installed within a locked enclosure? Ready access is not considered to be denied by a locked door or enclosure. Equipment would not be considered readily accessible if a snow blower, snow shovel, or ice pick were required to get to the disconnecting means.
Ready access in not denied by a lock when authorized persons with keys are readily at hand. An additional disconnecting means would not be required if the generator was otherwise readily accessible.

 

[iwire]

No Bob,
Look again at what I am saying. Look closely at the reference that I made to 225.31 and what the code panel said,
Nowhere does this statement relieve the other requirements of 225. the only relief is to 225.31

Mike, 702.11 does not even mention 225.31 directly

702.11 simply says (more or less) that the disconect required for seperate buildings or structures can be satified with the genrator disconnect.

Thats it end of story IMO and it appears that of the IAEI judging from there book of changes.

Following your logic if I was to use the Genset breaker I would have to provide a miniumum size genertor per 225.39 (Off the top of head)

Mike it is my opinion you want to make a mountain out of a mole hill, feel free if you want but I am not interested in following you down that path. :smile:

 

[jwelectric]

I am not disagreeing with either of you as to the second disconnect or the one required in 225.31 would not be needed.
This is clear and no argument is offered about the DISCONNECT.
In the comment made by the code panel 13-124 it is clear that the disconnect of 225.31 can be replaced by the one in 702.11.
I also agree with the answer given by the IAEI members as outlined in question 35 posted by M. D.

I don?t see anything in either the comment made by the code panel nor by the IAEI members that would relieve the other requirements outlined in 225 for OUTSIDE FEEDERS.
Both the comment of the code panel and the answer given to question 35 are very clear that 702.11 is addressing 225.31 a DISCONNECT and have no bearing what so ever with the FEEDERS.

Substantiation: The new text would permit the disconnecting means for the generator to act as the required disconnecting means for the circuit entering or passing through a separate building or structure as required by 225.31.

Answer to question 35; Section 702.11 was added in the 2005 Code which allows a readily accessible disconnecting means on, or part of an outdoor generator set to serve as the disconnecting means required by 225.31 when installed within sight of the building or structure supplied. To be considered within sight the equipment must be visible and not more than 50 feet

You are trying to take the word DISCONNECT and apply it to the complete installation.
A disconnect can be anything from a cord and plug to a switch gear.

What you are saying is that a molded case switch or a cord and plug can satisfy all the requirements for these feeders. This is far from the truth.
225 will still apply to the feeders. 702.11 addresses the disconnect required by 225.31 not the feeders or any other requirement for the disconnect.

Mike, 702.11 does not even mention 225.31 directly 702.11 simply says (more or less) that the disconect required for seperate buildings or structures can be satified with the genrator disconnect.

It is 225.31 that requires this disconnect that 702.11 is replacing therefore it is directly addressing 225.31.

Thats it end of story IMO and it appears that of the IAEI judging from there book of changes.

I agree that this is the end of story as it concerns the disconnect.

Following your logic if I was to use the Genset breaker I would have to provide a miniumum size genertor per 225.39 (Off the top of head)

Almost except these feeders are required to comply with 702.6

As can be seem here the disconnect on the generator is an on/off switch but the feeders are landing in a transfer switch at the building.
Here the Analysis is very clear that ONLY the disconnect is being addressed.
The feeder conductors will still have to comply with all the articles from Chapters 1 through 4 of the NEC.

 

[M. D.]

Bob, would this disconnect mentioned in 702.11 have to comply with 225.36?

Mike, I did not build the Generator set, your asking the wrong person ,I would think those that build them would be more able to help in this regard .The only thing I have to decide is, is this gen set listed, labled, and otherwise tested and approved for the use and if the requirements 702.11 have been met.

 

[jwelectric]

Mike, I did not build the Generator set, your asking the wrong person ,I would think those that build them would be more able to help in this regard .The only thing I have to decide is, is this gen set listed, labled, and otherwise tested and approved for the use and if the requirements 702.11 have been met.

I agree with you about what you have said above.

When I buy this generator and install it there is something that will require me to install. The generator by itself sitting there in the back yard will do nothing but burn gas unless I install something from this listed generator to the house, feeders.
The listing on this generator does not cover the feeders to the best of my knowledge. I can find generators and transfer switches in the UL listings but I can?t find anything that covers the feeders that supply the building except for the requirements of 225 in the NEC.

445.18 requires that this generator have a disconnect and 702.11 will allow this disconnect in place of the one required in 225.31.
I don?t see how the relief of the required disconnect in 225.31 by 702.11 effects the feeders at all.

There are generators on the market today that have a molded case switch installed instead of a breaker. Some have a kill switch and no overcurrent device at all.
Each of these generators have a disconnect that will comply with 445.18. Will this disconnect relieve the requirement of 445.12 and 13?
How will the kill switch affect the feeders or their requirements?

No I can not accept what you are purposing.

 

[M. D.]

Mike , I think you have you have lost me. If the thing or things equipped with gen. set are considered to be a diaconneting means they are a disconnecting means. What are we disconnecting ? Have you found anything at all that explaines your posistion. an example of some sort?? Other than that of your own creation?

 

[iwire]

Mike, you lost me as well.

We seem to agree that 702.11 allows the generators disconnect to serve as the disconnect required by 225.31.

But I think you feel that 225.36 still applies.

If that is your view IMO you are mistaken.

What are the first words of 225.36?

'The disconnecting means specified in 225.31 shall......'

Once I opt to use 702.11 I am not installing a disconnecting means as required by 225.31 I am using a disconnect as allowed by 702.11.

I don't know why you think that the protection of the feeders to the building has anything whatsoever to do with this discussion?

The over current device located on the generator set provides protection to the feeders, always has, always will.

The disconnecting means in Part II of 225 has to do with protecting the structure it serves, it has nothing to do with feeder protection.

There are generators on the market today that have a molded case switch installed instead of a breaker. Some have a kill switch and no over current device at all.

Show me some that would be used in this type of application we are talking about.

 

[jwelectric]

I do believe that you are about to get it but instead of starting in the middle let?s start at the beginning.

If the generator does not have a disconnect then the whole of 225 would apply including 225.31 but 445.18 requires that a generator have a disconnect.

702.11 Where an outdoor housed generator set is equipped with a readily accessible disconnecting means located within sight of the building or structure supplied,

an additional disconnecting means shall not be required

where ungrounded conductors serve or pass through the building or structure.

As stated in 702.11 if the disconnect is readily accessible and can be seen then the disconnect required by 225.31 can be omitted.
I can?t see how this relives any other sections found in the NEC especially those found in 225.32 through 39.

I don?t understand how you are coming to the conclusion that a disconnect on a generator relieves the requirements for outside feeders.

All that is being said in 702.11 is that the required disconnect of 225.31 can be omitted because the one on the generator that is readily accessible and can be seen fulfills the requirement of 225.32 The location of the disconnect.

That is why 702.11 states; with a readily accessible disconnecting means located within sight of
Remember that the definition of ?in sight of? means that the disconnect can not be hid by panel doors or the lid of a generator housing.

So yes if I choose to omit the disconnect required by 225.31 and use 702.11 then the required disconnect of 445.18 must be rated as service equipment.

 

[M. D.]

I once had an inspector who crouched down at a hot tub acess panel and say that he could not see the disconnect . To see it all he had to do was raise his head just above the rim off the hot tub , like a half crouch .I said are you kidding ,... your kidding right ? after about a 10 min talk he agreed that it was O.K.
Point is the disconnect equipped in the O.P. is readily acessible and as long as it is 50' or less and within sight of the building served , it is good to go.

P.S. That same inspector also wanted me to figure out a way to bond a steel door on a wood frame?? Some sort of bonding spring I guess ?

 

[iwire]

So yes if I choose to omit the disconnect required by 225.31 and use 702.11 then the required disconnect of 445.18 must be rated as service equipment.

Mike, we disagree, I think you can not see the forest for the trees.

 

[jwelectric]

Point is the disconnect equipped in the O.P. is readily acessible and as long as it is 50' or less and within sight of the building served , it is good to go.

It might be to superman but not to the average Joe. How can something that is under a locked lid be in sight or for that matter readily accessible?

Mike, we disagree, I think you can not see the forest for the trees.

Yes Bob we are in disagreement. I think that I am seeing the trees in the forest and you can only see the forest and not what makes the forest.

Here is the proper way to make the installation as outlined in the original post.

The service was upgraded so that the main disconnect would be located before the transfer switch.
The disconnect for the generator is not visible (with-in sight of) with the lid closed mandating the disconnect to be installed on the building.