One family dwelling main disconnect interpretation,

[copper123]

How do you guys interpret the readily accessible term for a main disconnect means for a residential home.

Where I live, most homes outside of the city limits are fed from overhead lines that usually incorporates a yard pole. The overhead drop usually feeds to a pole that has an overhead service loop with a meter main on it. The contractor then goes underground directly into the home using USE/RHW insulation wire. What I am seeing is that the contractors are saying that the main on the meter is acting as the main disconnect and that no other means to disconnect the conductors are needed. Sometimes, the yard pole is a fair distance away from the house. So?. What is your interpretation? The city where I work has adopted local amendments that state that a means to disconnect all conductors in the building from the service entrance conductors shall be provided on the buildings exterior. Basically, he always wants to see some sort of disconnect on the outside of the building. That is just in the city, so outside the city limits I am seeing just about everything. Nobody inspects dwelling units outside the city limits, so you are on your own.

So, I guess it comes down to readily accessible. Is a yard pole with a meter main on it readily accessible? Can it be capable of being reached quickly so it may be operated, renewed or inspected without having to remove obstacles or use portable ladders? I got in an argument with a electrical contractor the other day. We can get up to five feet of snow in the winter, and it would be a hard trudge to go out to the meter/main. I don?t think that is readily accessible. I think if you are not going to mount a disconnect on the exterior of the home, the panel needs to be mounted nearest to the point of entrance of the conductors and have a main in it. Also, what about bonding? If these people think the meter/main on the yard pole is the main disconnect, how does the grounding/bonding of the uferground, water pipe, come into play?

Thanks!

 

[hbiss]

Re: One family dwelling main disconnect interpretation,

The disconnect on the pole is the main disconnect required by the NEC. The panel in the house is a sub panel. It is not necessarily required to have a disconnect per the NEC however I would certainly use a main breaker panel regardless of how far the pole disconnect was from the house. Your local codes may modify this.

-Hal

 

[don_resqcapt19]

Re: One family dwelling main disconnect interpretation,

In my opinion, 225.31 and .32 requires the installation of a disconnect at the house. The bonding and grounding at the house should be per 250.32.
Don

 

[copper123]

Re: One family dwelling main disconnect interpretation,

would you consider the yard pole as a structure?

 

[don_resqcapt19]

Re: One family dwelling main disconnect interpretation,

would you consider the yard pole as a structure?

Yes.

 

[tonyi]

Re: One family dwelling main disconnect interpretation,

Article 100 has the "NEC" definition for "structure" and its a little different than what people commonly think of as a structure (i.e. a buildingish kinda thing)

That which is built or constructed.

Fence poles, lawn sculptures, upended car bodies (ala the Cadillac Ranch)... all sorts of odd things fit this loose NEC definition.

 

[itasca_mn]

Re: One family dwelling main disconnect interpretation,

Here in my area most new rural services usually involve a centrally located meter pedestal. It is extremely rare to see a disconnecting means installed at the meter location. As long as the main breaker inside the house is "nearest the point of entrance of the service conductors" (within 6FT is the general rule), it qualifies as the required disconnecting means. Another disconnecting means outside the building has not been required.

 

[explorer]

Re: One family dwelling main disconnect interpretation,

Copper,
My interpretation is you would need another disconnect at the house, either on the house or at the nearest point of entrance inside. 250.32(B)(2) allows you to install a 3 wire feeder from the pole and re-ground the grounded conductor and attach your grounding electrode conductors from your cold water and ground rods at the second disconnect on the house or inside. As long as there are no continues metal paths between buildings or structures involved. This is done as you know a lot on farms where a service on a pole feeds 2 or 3 buildings. As a rule of thumb many inspectors including myself allow the main on the pole to serve as a disconnect if it is located within 10 feet of the house. From what I understand there is talk about putting in the NEC an actual number in terms of feet, but it may never happen. I hope they do put a maximum distance on disconnects outside a building or structure, it sure would take away the controversy.

State Electrical Inspector
John Cosmo

 

[copper123]

Re: One family dwelling main disconnect interpretation,

Thanks Explorer for the reply.
I think the same way. One the lines of the 3 or 4 wire feed in 250.32B2 it talks about no continuous metallic paths bonded to the ground. I have always thought that this bond could include a water pipe that was feeding the building from another building. Do you agree? Basically, if you have any type of path between buildings, you can not run a 3 wire feeder and bond at the service entrance. So, would it not be safe to say, that if you have a combination meter/panel (exterior farm panel)that feeds two builiding from the same meter panel, and those two buildings have a water pipe between them, you could not run a 3 wire feed to each of them?

This is what I have always thought and the reason of course is you could have two paths back to ground in the event of a ground fault or heck at anytime I guess if the grounded conductor is bonded.

Thanks!

 

[copper123]

Re: One family dwelling main disconnect interpretation,

oh, explorer, i forgot to ask. If you allow the main disconnect to be within 10 feet of the house, and lets say its on the pole, do you allow the electrician to bring all electrodes into the panel in the house? Would this not be a violation? Wouldn't all the grounding electrodes need to go the the main disconnect on the pole??