Disconnect breaker outside

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petersonra

Senior Member
Location
Northern illinois
Occupation
Semi-retired engineer
I was talking with another EE today. He had a tale of electrical woe to tell.

He wanted to add service out to his garage, but has no space in his existing panelboard (has electric heat and all the spaces are used up), so he talked with an electrician about this problem.

Turns out he has a 200 CB downstream of the meter that feeds inside to the panelboard inside (that also has a main CB).

The electrician wanted $2000 to run UF cable from this CB in a trench into his garage to feed a new panelboard.

He thought this was a bit excessive so he rented a trencher and dug the trench, put a new panelboard in the garage and hired an electrician friend to connect the UF cable and make sure its done right.

First thing, they open the outside CB. He says it "made an odd noise", and the electrician says "that does not sound good".

Then the electrician loosens the lugs for the wires in the CB enclosure. All but one come loose easily. Electrician applies a bit more oomph to the lug to loosen in, and it comes off with a big chunk of plastic.

So, he calls a supply house and they tell him a std Sq D CB will substitute for the 40 year old breaker in the enclosure. So he runs off to buy a new breaker while the electrician routes the UF cable in the trench and conencts it to the garage panelboard.

He gets back with new CB. They realize they will need to pull meter to replace old breaker. Wait for electric company to show up. After electric company comes they replace breaker and electric company puts meter back in place.

I said " Why would anyone do such a thing in the first place"? He says, electrican claimed an outside OCPD device used to be required after the meter before entering house by REA. This requirement has since been dropped.

I say, why not just remove CB and use CB enclosure as splice box. He says, electrician had same thought after the fact, but by then was done.

I wonder why such an arrangement was once required.
 
Re: Disconnect breaker outside

Possibly the fire marshall or AHJ in that community required the service disconnect outside, so the service could be easily disconnected without requiring a fire fighter or other safety official to enter the home during an emergency.

Or possibly the local jurisdiction ammeded 230.70(A)(1) to not allow the disconnecting means to be "inside mearest the point of entrance of the service conductors".
 
Re: Disconnect breaker outside

for argument's sake,

is this a Service to a building or other structure, and if so, are the wires feeding it 'service conductors'???
 
Re: Disconnect breaker outside

You couldn't take the outside breaker out and make it a splice box,,,,,,,,,there would be nothing to protect the wire from the meter to the new garage panel(around here 5' max).UF is indicated,,,,,,,,what size uf? or was it urd? what did he do at the breaker? did he double up under the same lugs?(i hope not unless they were rated) was the urd 200a rated? (if so I don't see how he got both under the same lugs)The garage would have to be very close if someone is going to start arguing tap rules. This whole thing sounds fishy to me.

[ November 05, 2004, 03:29 PM: Message edited by: jap2525 ]
 
Re: Disconnect breaker outside

You couldn't take the outside breaker out and make it a splice box,,,,,,,,,there would be nothing to protect the wire from the meter to the new garage panel(around here 5' max).
Actually you could. See 230.40 Exception #3.
Don
 
Re: Disconnect breaker outside

Hello all

I think your original question was why or if the outside main disc. is required?

You did not say if the service conduit was run on the outside of the dwelling or inside to get to the main panel before entering the building.

The 2002 NEC. leaves this up to the local AHJ to set the distance you can run your service conductors once you enter the inside with your service conductors without having the main located outside.

See 2002 NEC. 230.70 (A)(1)

Inside nearest point of entrance to me would mean just on the other side of the wall but our building dept. allows 7 ft. and the electrical board changes this distance every few years or so. When I first started it was through the wall only any thing running on the inside of the building further than the wall thickness had to have the main on the outside.

Oh the reasoning of this rule is because of the fire hazard of a bolted fault which could possibly turn your service conductors cherry red before it would clear the fault on the high side of the transformer.This would lower the chances of having your house set on fire because of the main being downstream running through the inside of your house.

Ronald :)

[ November 05, 2004, 05:32 PM: Message edited by: ronaldrc ]
 
Re: Disconnect breaker outside

If the UF is run from the load side of the breaker they are no longer service entrance conductors but feeders, If exception #3 to 230.40 is used then they will be service entrance conductors and UF will not be allowed. But if the panel inside is has no spaces and the disconnect doesn't have lug's for use with two conductors then one of two methods will have to be used.
1. change the cable to the garage to URD or another service cable that would be allowed and use the 230.40 EX. #3, which will still require a tap of these conductors. or
2. Install a R-3 J-Box and tap the feeders to the house panel after the breaker/disconnect Which would allow the UF.
 
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