Accept 4-144: Services to be Outside

[kwired]

If it was customer controlled we would be talking about feeders not service conductors.

I have no experience with indoor utility / transformer vaults. When I say install in vault I may be using term that sets minds differently from what I am thinking.

I am talking about a room that surrounded by 2 inches of concrete or other equivelant and probably a 2 hour door. It may not be that practical vs just putting the service equipment in an outdoor location if that becomes the requirement. But I would sure think it should be an option if the requirement requires the service equipment outside the building. Is no different than the fact we can currently encase service conductor raceways in concrete and consider them outside building. It probably will create other headaches like what penetrations are acceptable to leave the vault to supply the structure?

[T.M.Haja Sahib]

I vote for placing the disconnector outside because the service leads up to the disconnector are not provided with any fuse protection upstream and so any short circuit in them inside the disconnector can result in a fire.

[Joethemechanic]

Probably the most common arc flash incident energy mitigation method I see, is to have a protective device 'remote' from the main service equipment.

But, what do we do when the utility transformer is inside an 'indoor vault'?

My first thought exactly

[sgreany]

I can see the point of a fireman entering a building and wanting a redily accesible means to disconnect energy sources to remove potential hazzards. How about we develop a meter with a disconnecting means that requires a special device that allows autherized personel to disconnect electrical sources . This would also solve the issue of metering personel having to install meters under load.

[kwired]

I can see the point of a fireman entering a building and wanting a redily accesible means to disconnect energy sources to remove potential hazzards. How about we develop a meter with a disconnecting means that requires a special device that allows autherized personel to disconnect electrical sources . This would also solve the issue of metering personel having to install meters under load.

Removing a meter still does not deenergize the service if you have CT metering. For meters that do open the service when removed - firemen are already wearing PPE when they remove them.

[texie]

I have a different angle to this idea that would not only give you the safety for fire personnel to remove power to a building but also make it much safer in pulling a meter to change out a meter.

My idea is to require meter bases with a line side disconnect built in to cold sequence the meter, some POCOs already require this for services, what if we were able to get a requirement that would require only 400 amp and below meters to have a built in feature that would allow the service entrance conductors to be disconnected, this would also increase the safety for POCO employees changing meters, as well as giving a place to kill the power to a building in an emergency.

One. there would be no requirement of relocating the service main disconnect point to the outside of the building because it would not have any OCPD so 4-wire feeder would not be required as an added cost.

Two. it would be a standard available meter base so the cost over a separate disconnect with OCPDs would be minimal.

Now we are offering safety to a wider group of people with a much less cost fiscal impact that can block many codes from being accepted, the exception to this requirement would be if a disconnect with OCPD's were installed.

I'm all for safety but lets keep the cost down when we implement it?

now I would say this approach would require any CT-ed services to be exempt so this would limit this to light commercial under 400 amps single phase or 200 amp 3-phase as these are the largest metered services we can get before our POCO requires CT metering.

I would believe that the design could be very similar to the by-pass meter bases where instead of connecting the line and load together it would just isolate the line lugs from the top meter stabs.

I'm sure that the manufactures of meter bases would jump on this requirment if they think they would make a buck, H'mmm sounds like the AFCI story

Looks like Milbank has a product for you: http://www.milbankmfg.com/products/c...s/PDF/5764.pdf

[petersonra]

New buildings rarely have fires anyway, so my suggestion would be to require these only in buildings that are > 40 years old.

[kwired]

New buildings rarely have fires anyway, so my suggestion would be to require these only in buildings that are > 40 years old.

What happens in 40 years when it is no longer a new building?

Why is there less fires in new buildings?

Newer buildings are designed to standards that help inhibit the spread of fire if you have a fire. Many older buildings are brought up to these standards whenever any rennovations are made. So if you have a fire in a newer building you likley have less damage.

[augie47]

I used to think it was a great idea until I saw some pictures of nothern plains homes with snow
5 ft + deep surrounding the homes (roof high dridts on some sides)....
Outside disconnects are great here in the South, but I wouldn't want to shovel snow to get to mine.

[George Stolz]

Gus, in my area 99% of houses feature an outside disconnect. How often do you have to reset yours?