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Re: Max distance of main panel from meter [Re: jdevlin] #192976 03/12/10 11:17 PM
Joined: Mar 2004
Posts: 947
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twh Offline OP
Member
Quote
It's 2 " of concrete not conduit
The likelihood of a typo increases by the square of the number of readers.

I understand the reason for the rule. It's the interpretations that are interesting. The phrase "as close as practicable" has distances and wiring methods attached. It's almost like we still have amendments.

Tools for Electricians:
Re: Max distance of main panel from meter [Re: twh] #199991 03/16/11 06:44 PM
Joined: Mar 2011
Posts: 28
mersadrad Offline
Member
I would say that rule is made considering voltage drop. So "as close as posible" does not seem defined completly. Voltaage drop can't be more that 5%.
From service to main panel 2%.
From main panel to branch 3%.


Now I am still an apprentice so I might be wrong, that is why I like to ask questions. Forgive me if I am anoying.


“If you don't know where you are going, any road will get you there”.
Re: Max distance of main panel from meter [Re: twh] #199995 03/16/11 08:06 PM
Joined: Feb 2011
Posts: 56
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pooL8 Offline
Member
B.C. Directives say that any distance greater than 1.5m is considered unacceptable without prior consultation with Authority.
"To limit the risk of fire, because service conductors lack effective overcurrent protection."

Ummmmmmmm....

I'm wondering why that should be up to us to 'solve'. Afterall aren't conductors supposed to have effective overcurrent protection?

Put overcurrent protection in the meters is an idea. Then we can run them wires as far as practicable smile
Thanks Hydro! (I'll take one of those electric crimpers too)


Re: Max distance of main panel from meter [Re: mersadrad] #199996 03/16/11 08:25 PM
Joined: Jun 2006
Posts: 613
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mikesh Offline
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Originally Posted by mersadrad
I would say that rule is made considering voltage drop. So "as close as posible" does not seem defined completly. Voltaage drop can't be more that 5%.
From service to main panel 2%.
From main panel to branch 3%.


Now I am still an apprentice so I might be wrong, that is why I like to ask questions. Forgive me if I am anoying.


The issue is unrelated to VD in this case. The conductors ahead of the main switch are considered to have no overcurrent protection. You probably have seen fuses on the pole top transformer that supplies the 6 to 10 houses you are all connected to. If one of the ungrounded (hot) wire faults to ground in a service raceway the utility transformer might see that bug bump in current as a load rather than a fault. I have certainly seen a few service panels and raceways burned completely away before the fuse on the transformer or a connection in the meter or triplex opens under the heavy current flow. If this service pipe was inside your walls it might set the house on fire before the fuse on the transformer blows. It is very common for utility transformers loaded to %200 of their rating when connected to residential services. In the case of the panels I have seen burned away I got to the house after the fire trucks.
By encasing the raceway in concrete it is hoped that the concrete will enclose the melting raceway and protect the combustible wall it is inside. Eventually the fuse will open or the raceway will burn away enough to stop conducting fault current.
Then there is the problem of theft from the utility. We have seen more than a few raceways cut open ahead of the meter to tap the utility wires. Pot growers seem to love to do this.

Re: Max distance of main panel from meter [Re: mersadrad] #200000 03/16/11 09:33 PM
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pooL8 Offline
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Quote
Forgive me if I am anoying
Okay... but I won't forgive you for saying THAT!

Dude. Some of us don't look down on 'apprentices' (people). Talk to us, not the ones that do.

Re: Max distance of main panel from meter [Re: twh] #200012 03/17/11 12:20 PM
Joined: Jul 2005
Posts: 183
J
jay8 Offline
Member
If you have a situation where "as close as practicable" is not a good location for your panel, you could consider a fusible disconnect after the meter, then place your loadcenter where ever you need at whatever distance.

This is particularly suitable when the meter is mounted on a garage, so the disconnect can go inside the garage, or where there is room for a fusible disconnect inside the house but not a combination panel.

.

Re: Max distance of main panel from meter [Re: pooL8] #200058 03/18/11 08:32 PM
Joined: Mar 2011
Posts: 28
mersadrad Offline
Member
I did service entrance 400A, 200A, and 100A. I do remember
connecting meter box. It is logic to fuse meter, but I never saw one (not plugged in).
So we need a disconect switch to be as close as posible.




“If you don't know where you are going, any road will get you there”.
Re: Max distance of main panel from meter [Re: mersadrad] #200065 03/19/11 01:23 AM
Joined: Feb 2003
Posts: 939
F
frenchelectrican Offline
Member
I will quote both USA and France side with the max distance from meter to main panel the USA side it will varies a bit depending on which states they use that codes but most of them say short as possible so tyically less than 2 meters from the main meter but few do can go much as 4 or 5 the most.

In France we are limited to 3.5 max distance but most case they are useally on outdoor main disconnect switch.

Merci.
Marc


Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)

Re: Max distance of main panel from meter [Re: twh] #215587 06/06/15 08:46 AM
Joined: Jul 2008
Posts: 98
B
brsele Offline
Member
I'm bringing this back up for a situation that I have now.

A customer is building a house and wants the panel located in a interior room about 35' away from the meter base.

The inspector said that using rule 6-208, that I'd be fine. This would mean that I would bring conduit straight down from the meter base, go below grade, sweep 90 through the foundation wall, run along below the basement slab and sweep 90 up into the mechanical room and straight into the panel.

My concern is 6-300(3).

Opinions please.

Thanks... Bruce

Re: Max distance of main panel from meter [Re: twh] #215588 06/06/15 09:46 AM
Joined: Jan 2005
Posts: 5,316
renosteinke Offline
Cat Servant
Member
There's the "legal" answer, and the "reality" based answer.

The US rule is that the main disconnect must be as close as practical to the meter / service entrance. While MOST places have long understood this to mean either right next to, or on the interior wall face immediately behind, the panel... some places let the rule be stretched to allow the OP's proposed situation.

This has changed in practical terms. It's rare now to have just a simple meter base; most either have a disconnect in them, or are even meter/ disconnect / panel combos ("All in Ones").

For my house, I used a small "All in one" at the service drop. At $45, the unit cost less than most simple meter bases. With only 10 spaces, this panel isn't very large- so I use it to serve a second panel inside the house. The remaining outside spaces are used only for feeding outside loads, like the air conditioner and a receptacle at the service.

I really object to 'stretching' the rule, as proposed by the OP. Sure, he says 'conduit,' but I've seen it done with SER cable. Face the truth: walls are nowhere near thick enough for a proper bending radius with conduit. Are your walls a foot thick?

Here in Arkansas, there have been instances of someone piercing the SER - which has NO overcurrent protection, or means to disconnect power- with a nail. One nasty surprise when you want to hang a picture!

Again, to use my house as an example, I fed the interior panel using a mix of RMC and EMT- surface run to an LB into the crawl space, then under the floor joists and up into the panel. with (nominal) 10" floor joists and hanging the pipe from strut, there was plenty of room for the required radius, and the ability to use another LB had I desired.

My arrangement replaced the original service, which ran unfused in SER through two walls and across one room's ceiling to feed an old panel in a closet. That room had later been covered with paneling, with dozens of nails that were plenty long enough to pierce the SER as it was installed. Only luck prevented a problem.

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