Generator disconnect

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augie47

augie47

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Tennessee
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State Electrical Inspector (Retired)
I have a generator disconnect, service rated, located inside the generator cabinet accessible by opening the side compartment with a special wrench. I say this is not "readily accessible" but the definition only supports this by the wording "being reached quickly". Another inspector is of the opinion that as long as the tenant has access to the wrench the breaker is "readily accessible".
What say you guys ?
 
augie47 said:
I have a generator disconnect, service rated, located inside the generator cabinet accessible by opening the side compartment with a special wrench. I say this is not "readily accessible" but the definition only supports this by the wording "being reached quickly". Another inspector is of the opinion that as long as the tenant has access to the wrench the breaker is "readily accessible".
What say you guys ?
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I am on your side due to this
702.12 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 serve or pass through the building or structure. The disconnecting means shall meet​

the requirements of 225.36.

The word within sight would seal the deal for me. If it is behind the cover it cannot be seen from the structure.
Also 702.12 states that it shall meet the requirements of 225.36. 225.36 takes you to 225.31 which leads to this

225.32 Location.​
The disconnecting means shall be installedeither inside or outside of the building or structureserved or where the conductors pass through the building orstructure. The disconnecting means shall be at a readilyaccessible location nearest the point of entrance of the conductors.For the purposes of this section, the requirements
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in 230.6 shall be utilized
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.

The disconnect SHALL BE at a readily accessible location NEAREST the point of entrance.
 
As long as the key or spanner wrench is available to the tenant and the generator set is within sight of the building or structure it serves it would be compliant. The lock or safety latch does not preclude it from being readily accessible unless the generator is mounted above grade requiring a ladder.

702.12 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 serve or pass through the building or structure. The disconnecting means shall meet the requirements of 225.36.


Accessible, Readily (Readily Accessible). Capable of being reached quickly for operation, renewal, or inspections without requiring those to whom ready access is requisite to climb over or remove obstacles or to resort to portable ladders, and so forth.
 
This is kinda grey area on what is considered "Readily accessible", I have had some inspectors accept it behind the cover, others not. The key issue I would contend would be equal to having a padlock on the service disconnect, the disconnect is accessible, but a key would be required if it is locked. Code does not prohibit the installation of a padlock on the service disconnect, but local fire codes may. I have installed Generators that have a flap over the breaker, where it would be accessible without opening the generator door, others have E-Stops mounted on the outside.
 
I read 110.26(F) as permitting the door to the disconnect to be locked, however, the disconnect behind the door at the generator would not be "within sight" from the building and that will trigger a requirement for a disconnect at the building.
 
dwellselectric said:
Who ever runs the gas line to the generator has to put a shutoff at the generator and I've always considered that the shut off. Generator can't run if you shut that off :)
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I have a generator that has a valve to shut off the gas. Once the gas valve is turned to the off position the generator will run for another 15 to 20 minutes. Would this be considered a means of disconnect.
 
jwelectric said:
I have a generator that has a valve to shut off the gas. Once the gas valve is turned to the off position the generator will run for another 15 to 20 minutes. Would this be considered a means of disconnect.
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No it would not, and in any case it would not meet the definition of Disconnecting Means.

Disconnecting Means. A device, or group of devices, or other means by which the conductors of a circuit can be disconnected from their source of supply.
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Even though the "prime mover" is off the conductors are still connected to the source of supply.

Roger
 
don_resqcapt19 said:
I read 110.26(F) as permitting the door to the disconnect to be locked, however, the disconnect behind the door at the generator would not be "within sight" from the building and that will trigger a requirement for a disconnect at the building.
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I don't agree with this. By this train of thought, no disconnect would be "within sight" if it had a door, such as a panel used for a disconnect. If the door was closed it wouldn't be within sight.
If the disconnect housing, or access to it, is within sight of the building, I believe it meets the requirement of "within sight".


Example: A water heater has to have a disconnect "within sight" and a panel (with a door) is "within sight" that is an acceptable disconnect.
 
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Little Bill said:
I don't agree with this. By this train of thought, no disconnect would be "within sight" if it had a door, such as a panel used for a disconnect. If the door was closed it wouldn't be within sight.
If the disconnect housing, or access to it, is within sight of the building, I believe it meets the requirement of "within sight".


Example: A water heater has to have a disconnect "within sight" and a panel (with a door) is "within sight" that is an acceptable disconnect.
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I see a big difference between an electrical panel with a door and an generator enclosure with a door. I would accept the panel with a cover or door as being "within sight" but not the generator enclosure with a disconnect inside a cover or door on the enclosure.
Some generator enclosure manufacturers put a window on the door so that the disconnect can be within sight.
 
don_resqcapt19 said:
I see a big difference between an electrical panel with a door and an generator enclosure with a door. I would accept the panel with a cover or door as being "within sight" but not the generator enclosure with a disconnect inside a cover or door on the enclosure.
Some generator enclosure manufacturers put a window on the door so that the disconnect can be within sight.
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I have to know why ???:huh:
 
If the whole reasoning for a disconnect being "Within Sight" is so you can see for your self that no one is near it while your working on something it's feeding, then i see your point.
You could see someone standing in front of a panel fixing to open the door and turn something on and you could yell at them that "Hey get away from there I'm working on something".

Whereas even if a generator enclosure happened to have a window on one side where you could see the breaker through the window, someone could be hiding on the far side of the generator enclosure and slowly be reaching thier hand inside the generator and around to turn the breaker on and you'd never see them?

In my mind the "Disconnecting Means" being "Within Sight" means just that.
If you cant feel comfortable about knowing that no one is around a disconnecting means that you shut off to work on something, then it's not "Within Site" in my opinion.
 
don_resqcapt19 said:
Some generator enclosure manufacturers put a window on the door so that the disconnect can be within sight.
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And is the breaker "visible" through that window from a distance of 50 feet, the distance stated in the definition of "in sight from"? I think not. Suppose that window is not on the side of the generator that faces the building, but the enclosure that houses the breaker can be seen from the building. Would the install only be compliant if you turned the generator such that the window can be seen from building, even though the breaker itself cannot be seen at that distance? Is the rule saying you must see the breaker itself, or just be able to see the enclosure that houses the breaker?

We need to keep in mind that a "disconnecting means" is not intended to be an emergency shutoff mechanism. It is not there to allow you to quickly turn off power because someone's shirt is caught in a conveyor belt, and you have only about 5 seconds to save the person's life. It is there to establish a safe condition, either for maintenance purposes, or to allow fire fighters to combat a fire. And before anyone tries to point out that fires are emergency situations, I'll point out that it is allowed by code to have the building's only "main disconnecting means" located two floors down from the main entrance, within a locked main electrical room. You cannot quickly turn off power using that breaker or switch.
 
So what is the reasoning for a Disconnecting Means to be "Within Sight"?

Is it so you can keep an eye on it while working on something that it feeds or so you dont have to look more than 50' an any direction to see where its fed from?

Depending on how the above question is answered has a lot to do with wether its within sight or not.

If I'm looking at the back of a 36" wide 72" Tall Breaker Panel, is the disconnectiong means still considered within sight? Not to me its not, the disconnecting means "enclosure" is but not the actual Breaker.

As far as that goes no breakers in a panel with the cover shut to me is "Within Sight". Now if is was a disconnect you could probably see the handle and I would consider it in sight then.

I've probably already said too much.:?
 
Little Bill said:
I don't agree with this. By this train of thought, no disconnect would be "within sight" if it had a door, such as a panel used for a disconnect. If the door was closed it wouldn't be within sight.
Example: A water heater has to have a disconnect "within sight" and a panel (with a door) is "within sight" that is an acceptable disconnect.
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Starts to make you wonder doesnt it.
Technically no the disconnect (Breaker) is not within sight. The Breaker Enclosure is, which is not the disconnecting means.
Now a true disconnect, Yes.

I think this will be an ongoing arguement until it is clarified wether the "Disconnecting Means" or the "Enclosure that Houses the Disconnecting Means" has to be Within Sight.

JMHO.
 
Let's take it to the next level: The means by which the conductors are disconnected from the supply are the breaker contacts. But they are not "within sight," because the breaker handle is in the way. So I guess a breaker cannot be the disconnecting means, and we have to resort to knife switches. :happyyes:
 
charlie b said:
Let's take it to the next level: The means by which the conductors are disconnected from the supply are the breaker contacts. But they are not "within sight," because the breaker handle is in the way. So I guess a breaker cannot be the disconnecting means, and we have to resort to knife switches. :happyyes:
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Technically Yes.
See, we've all been breaking code since day 1.:)
 
and you'd have to bypass the door keep on the disconnect to see the blades disengage so you couldnt use a knife switch either.
 
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