Separate Disconnect before Main Panel (new construction)

[72Anthony]

Does it make sense to install a separate disconnect before the main panel for new construction?

In Houston, it is common for the meter box to be installed on an exterior wall of the garage and have the main panel installed on the interior side of the same wall.

In the current house, if I am adding a circuit to the main panel, I can flip the main breaker, but the main lugs are still hot and exposed, especially if routing wire from above.

I am building a new house that will also have a standby generator with automatic transfer switch.

My thinking is that with the separate disconnect, I can more safely isolate the power company's feed when I need to work on the main panel.

If I add the disconnect, does the main panel still allow the neutral and ground wires to be tied together or is it treated like a sub panel, where the neutral and ground are tied together at the disconnect?

Thanks,
Anthony

 

[Gooch]

Does it make sense to install a separate disconnect before the main panel for new construction?

In Houston, it is common for the meter box to be installed on an exterior wall of the garage and have the main panel installed on the interior side of the same wall.

In the current house, if I am adding a circuit to the main panel, I can flip the main breaker, but the main lugs are still hot and exposed, especially if routing wire from above.

I am building a new house that will also have a standby generator with automatic transfer switch.

My thinking is that with the separate disconnect, I can more safely isolate the power company's feed when I need to work on the main panel.

If I add the disconnect, does the main panel still allow the neutral and ground wires to be tied together or is it treated like a sub panel, where the neutral and ground are tied together at the disconnect?

Thanks,
Anthony

you can do that, but you need to bond the neutral and ground at the exterior disconnect and then run 4 wire feed to the interior panel.

 

[JoeFin]

Does it make sense to install a separate disconnect before the main panel for new construction?

Thanks,
Anthony

Short answer - No

In residential you can always remove the meter and that is your disconnect

 

[Norcal]

Lots of PoCo's take a dim view of people tampering with their cash registers, the service disconnect outdoors is fine but then the "main panel" will have to have neutrals (grounded conductors) & grounding conductors separated, here in CA most homes use a "all in one panel" such as the one shown below so the the main & distribution section is outdoors.

 

[Gooch]

Lots of PoCo's take a dim view of people tampering with their cash registers,(pull the meter) the service disconnect outdoors is fine but then the "main panel" will have to have neutrals (grounded conductors) & grounding conductors separated, here in CA most homes use a "all in one panel" such as the one shown below so the the main & distribution section is outdoors.

Never understood the appeal of them. Last thing I want to do is go outside to reset a breaker. Especially during a storm or in the winter.

 

[Norcal]

Never understood the appeal of them. Last thing I want to do is go outside to reset a breaker. Especially during a storm or in the winter.

That's 'cause you live in god forsaken country.

 

[JoeFin]

Lots of PoCo's take a dim view of people tampering with their cash registers,(pull the meter)

No not really

Actually PG&E only claims the wire coming into the socket and the meter it self. If any thing goes wrong with the meter-socket it is the home owners responsibility to repair it.

I had to call them a couple months ago to unlock the meter because I had dropped a screw down there and it was hanging dangerously close to the bare buss bars. I just knew if I banged on the enclosure to rattle the screw down it would have shorted out.

So I called them up and they sent some one out in about 1 or 2 hrs to unlock it

Felt kinda dumb but nothin went BANG so it was a good day

 

[Aceman]

In the current house, if I am adding a circuit to the main panel, I can flip the main breaker, but the main lugs are still hot and exposed, especially if routing wire from above.

I'll throw another option out, wrap the exposed lugs with a mastic pad. It's a thick sheet of insulating material that's sticky on one side and can be formed into most any shape.

http://www.cesco.com/b2c/product/19...81_a_7c19986&gclid=CJ7tn-vL97sCFQeVfgodTkoA0g

 

[EOC_Jason]

Short answer - No

In residential you can always remove the meter and that is your disconnect

LMAO... Only if you want Centerpoint to show up a few days later and install a locking ring on your meter can. They installed smart meters a few years back and now watch things like a hawk. They were getting majorly ripped off in the shady neighborhoods before the upgrade so now they are super paranoid.

Short answer, yes you can install a disconnect between your meter can & breaker panel. In fact, you HAVE to install one (outside) for anything above 200 Amp service (I guess so fire department can throw disconnect then pull meter).

Read the service standards PDF ON THIS PAGE... It has lots of good information and plenty of illustrations of how Centerpoint wants things done.

You can also call up Centerpoint if you have questions. There should be a service rep # in that PDF for your area that can help you.

I remember during Hurricane Ike, since the power was out for two weeks, we took that opportunity to change out our breaker panel. Obviously pulled the meter can since nothing had power to be safe. One of the few times it was possible short of calling them to come out and pull the meter for you.

 

[Norcal]

No not really

Actually PG&E only claims the wire coming into the socket and the meter it self. If any thing goes wrong with the meter-socket it is the home owners responsibility to repair it.

I had to call them a couple months ago to unlock the meter because I had dropped a screw down there and it was hanging dangerously close to the bare buss bars. I just knew if I banged on the enclosure to rattle the screw down it would have shorted out.

So I called them up and they sent some one out in about 1 or 2 hrs to unlock it

Felt kinda dumb but nothin went BANG so it was a good day

The Customer is responsible for furnishing & installation of the meter socket & the only way they can claim ownership of any wiring is if it's a underground service, they still are going to take a dim view of a customer pulling the meter, I have pulled them for a good reason, one time for power off in parts of the house, because of something hitting the meter although it did not break the glass, found only 120 volts ahead of the main, tried to plug the meter back in w/o cutting the seal, which found out rather quickly was not going to work so cut the seal pulled the meter & reset it & told the customer to call PG&E to reseal the meter all was fine, the whole thing was rather strange but the panel was a Sylvania (Zinsco)...

 

[Grumpy365]

I did it.

I have 400 amp service. I broke it into 2) 200 amp disconnects. One disconnect then feeds the house breaker box and the other will feed a shop some day, but now it is just off.

 

[Charles (in GA)]

Short answer - No

In residential you can always remove the meter and that is your disconnect

You can, but the power company does not look kindly on it. In some states, breaking the seal on a meter can become a felony depending on the circumstances.

Many localities, especially here in the south REQUIRE a outside disconnect switch, largely for fireman to use, as the power companies discourage the pulling of a meter by anyone, due to the exposed terminals and possibility of someone getting injured.

In the big scheme of things, an outside disconnect does not add a lot of money to a electrical installation.

Charles

 

[LennyTheLizard]

When I put my shop in, power company installed a new meter box that I thought was pretty slick. It has the disconnects under the meter that allow you to shut off any of 3 loads separately. I only have 1 meter, but my house feed and shop feed can be switched off independently, plus there's an empty slot left over.

Power company didn't charge anything to put it in, but they had to upgrade service anyway when I added shop (200A -> 400A).

 

[EOC_Jason]

Power company didn't charge anything to put it in, but they had to upgrade service anyway when I added shop (200A -> 400A).

Yeah, the power company here many many years ago would give you a meter can, all you had to do was go to their place to pick it up. Now they would probably laugh at you if you asked. I guess why bother giving something away when you already have a monopoly?