Went into addition friend of mine is doing and he had a 125a sub panel w/no main breaker.It was feed from a 200 amp panel.He says the builder told him that since he only had 3 wires coming to the 200a panel all he needed was 3 to the sub.I`m I correct in that if the panel he`s feeding from has more than 6 breakers he needs the main?He also needs 4 wire to the sub panel.Thanks in advance.

Talk to an electrician. Talk to an electrician. Talk to an electrician.

The sub-panel does not need a main breaker in it. The number of circuits doesn't matter.

The wires feeding the 125A sub-panel DO need a breaker in the 200A main panel.

There must be 4 wires from the main panel to the sub-panel (2 hots, neutral, and ground), unless the feed is in grounded metal conduit.

JBD did your enter key get stuck or you just not having a good day.That was the purpose of the post was to ask an electrician.Sorry if the question somehow bothered you.I detect sarcasome in the post. If it did why even respond.ThanksThanksThanks.I just wasn`t sure about the main.I`ll get a code book and find what had me confused something about if the panel feeding from had 6 ocp`s the panel would need a main but seems I`m wrong.Quess thats why I`m but a we helper maybe one day I`ll be a code wizz like you guys.Maybe I`m not having a good day
Sorry

Im with JBD Im with JBD Im with JBD

read 408.16, 230.71
read 408.16, 230.71
read 408.16, 230.71

Oh c'mon guys, Reel-Break's one of us ain't he?



I mean: I've asked some fairly elementary Q's about control work cuz I ain't done much of it, give 'em a break on the resi Q's...

We're all on the same side here!




[This message has been edited by sparky66wv (edited 08-06-2002).]

Reel-Break

I always think it's a good idea to have a main in the sub panel, but you may be thinking of 230.71(A) which talks about when a Main is required for the Service. Take a look and see if that's what you're thinking of.

Bill

Bill

Is installing a main breaker in sub panels pretty standard for your area or is it something you just like to do? Out here on the west coast you almost never find a main breaker in a panel unless its the service or connected to a xmfr. Most of our residential services are combination panels (meter, main and load center). I have noticed that most of the load center in mail order catalogs have main breakers. Out here the supply houses stock very few with mains. If a main breaker is needed you usually have to back feed one with a retainer clip.

Curt

Curt,

Retail stores really only carry MB panelboards or smaller MLO (4 to 12 cir). We don't put loadcenters outside houses here. I've never seen one. Maybe no one wants to go outside in the snow ??

Meter-Mains aren't very common either. They are generally only used when they have to be because a 200A Meter-Main runs over $400 and I've paid as much as $8 /ft. for 2/0 SER cable (Copper here) So that means the the main must be in the Panelboard.

Many times when I've installed residential sub panels it it for a Workshop or Apartment. I think that most people generally like having a Main for the panel, especially nowadays when more people are attempting varying degrees of electrical work. It's just a bit more convenient I think and maybe a little more feeling of security if they don't have to worry about someone turning the power back on from another location.

Some of the GE panels are convertible from MLO to MB with a little kit too that goes on top and screws right into the lugs.

Bill

Sub-panels over here usually have a main switch (not a main C/B) on them as well, at least in residential work.

Yeah , Virg is right..sorry Reel-Break, just goofin'...

on topic...

If i'm 'let' to do a quality job, i'll do a meter/main and have mains in all subs, and TVSS on all the mains

(This is where you guys may differ)

This is just my technique .....the 'let thru' is then a combination of the mains in series....helps all those frail AFCI's survive...

Ok I read the articals and I`ll asure you I`ll remember this one.I don`t want to be removed from the board but why If someone ask a question if it is to elementary for a good responce or should I say a positive one why would you bother to reply.I went back last night and searched everyones past post and questions and to be honest I knew some of the answers and even thought to myself hey I`m not to stupid after all.Well lets stop the mud slinging. I`m sorry for the negative remarks to JBD posted yesterday.
Back to drillin and pullin wire.

Reel-Break,

I ment to be only a little sarcastic. This comment was really intended for your friend.

As I read your post it looked like your friend wanted us to defend ourselves against the builder.

May be its time for a group hug.
Jim

Awwwww!

*group hug*

'66wv—

Would you please email me one of those little plastic-lined bags from an airplane? I think I'm going to barf any moment now. ;-)

Seriously, this discussion sounds a lot like another “regional differences—local customs” thing. Seems in this area [NorCAL] most always NEMA 3R meter/main/branch-circuit combinations for residential are the norm, but then snow fell for a couple of hours last February, and a taking a leak on the sidewalk got rid of it. 1976 was the last one before that.

Although it’s not against local/national codes, inspectors would wig out not seeing at least a main disconnect at the meter. {“What if there’s a fire?” they’d say.} The house I’m in has a cheeseball 125A Murray everything/combination box that came with air-conditioning in 1979, and next to it is the original double-plug-fuse-main gutted-for-a-jbox-now from 1935. Wall-hung/all outdoors is routine for up to the 400A bolt-on meters.

please,Bjarney...i've been barfed on enough in EMS....


All these Genny's & T-switch deals out there the customers show up with, never know if thier service rated, AIC , etc....

I guess i'm just a meter/main advocate.

We have one ( of many) local poco's that asks for meter/mains...

asks... not demands.....

Reel Break, I'll try to answer your question. I am assuming yor 200A panel has a MB and is the service equipment. The six circuit rule is often misunderstood. This comes from 230.71 that states that up to six discos, switches or breakers may be grouped together with out a main at the service equipment. This rule has nothing to do with your 125amp sub panel. Yes you will have to take a fourth grounding conductor to the panel. You are not required to have a main in the sub panel but I know of inspectors that require factory installed (bolt in, not back fed) mains in all subs for safety reasons.

Hope that helps.

Arseegee, these inspectors that require this, are they under the NEC? there is no requirement for a main breaker in a "sub panel". If these inspectors are under the NEC they have no right to require anything over and above regardless os their views on safety or such. I know this is off the topic but I will never accept inspectors making up the rules as they go. It is not right and it is counterproductive to everything that the NEC is.

E-scott, I went round and round with an inspector in a neighboring county over this, I drilled him on the code and finally got him to admit that I was right. He then stated that the NEC is the minimum requirements for an electrical installation and that he was requiring a main in the sub panel. I then walked away shaking my head knowing that I would have to play his game to get passed.

arseegee ---

The local code (NEC) is the minimum you can build to. It is also the maximum the AHJ can enforce.

To resolve this problem with the inspector, have him write a violation notice, appeal to the appeals board, and the appeal to the local court. (I suspect that is the appeals order in most juristictions.)

Appeals to the local court are often free if you win.

Drill the inspector in court with the same questions and you will prevail.

The inspector will not mess with you in the future.

George, if it was a bigger issue I would have done that, but this guy was a p*cker head and wasn't worth the time. I slammed him and he knew it but I wanted to move on. I do over a 100 dwellings a year and don't have much time for bickering with a guy who has only had about two weeks worth of class on the code. But perhaps I'll have the pleasure of working in his jurisdiction again one day.

GRRRRR

Electricmanscott said GRRRRR

I am with him all the way on that.

I recently went the two rounds with an AHJ over the outside mains issue. I had installed a twelve slot, 200 amp, MLO panel as service equipment on the exterior and used double pole breakers to supply the water pump, the sewage lift pump, two outbuildings and two panels in the main building. The insurance company wanted only one disconnect between the water pump and public power because of the domestic water piping also serving residential automatic sprinklers. The first round was with the inspector himself. He was really angry when I would not yeild and truly furious that I would demand a written notice of violation quoting chapter and verse. The second round was with the supervisor but as soon as it became clear that I would appeal any demand that I install a main breaker they claimed that the fire department wanted it. I told them to ask the fire department how it feels to want because by know I was really ticked off. The chief electrical inspector for the state board was telephoned at my request and asked the local fellas how many breakers there were and when they answered six he said "you will loose any appeal that the installer brings to the state board." They then agreed to sign off on the job.
--
Tom

So, ignoring the other violations, such as the lack of marking the GC white (or gray), and assuming less than 6 CB's, then this installation is OK?

Even with the bus unprotected up to the 4160V fuse before the X-former?



[This message has been edited by sparky66wv (edited 08-15-2002).]

sparky66wv

If the panel is listed as service equipment then yes that is a code compliant way to install a service. More importantly it is a superior way to supply a water pump on rural property were the occupants are on there own until the FD can reach them after a long run. The last thing you want is to have a fault caused by the fire to deprive you of the only water for fighting that same fire.

The issue of the faults to which the service equipment may be exposed is not new. They are what fault current calculations are all about. As long as the withstand listing of the equipment and the breakers installed in the service meet the available fault current all is well. Why should we believe that the buss bars being part of the service entry conductors makes those problems any worse.
--
Tom

[This message has been edited by tdhorne (edited 08-16-2002).]

OK, I'm trying to follow you here...

Let's assume it's listed for service equipment. There is no Breaker upstream of the branch circuit breaker for the pump, so nothing protects the exposed parts of the bus. I can't see how the best OCPD can protect upstream of a fault, and I realized that service cable is under the same risk, but it is covered with insulation, the bus isn't.

Some bus designs, particulary SQ D Homeline, present the hazard of getting across 240V while working on a hot panel. Many people don't like GE, but the buses in GETHQLs are much better protected from accidental contact.

I have more to learn before becoming an inspector; I would have tagged it and I would have wanted a main.

[This message has been edited by sparky66wv (edited 08-16-2002).]

There are many arrangements of service equipment that do not provide overcurrent or fault protection to buss bars. Sectional switch gear with six main switches is a good example. We have all seen multiple disconnects used as service equipment. The tap conductors from the service conductors to each disconnect are also without any OCPD. The Buss bars are insulated from contact with other conductors and grounded surfaces by air. That is why they are rigidly held in place. They are protected fro accidental contact by the enclosure dead fronts instead of insulation that covers the conductors.
--
Tom

I just recently done a 125amp sub panel here in fayetteville, nc and the inspector said now we wire it just like a service. over six disconnects, has to be a main.
also we do not have to run the fourth wire with the feeder. we had to install a ground rod. like we say it is up to AHJ in differnt locations. we just have to passify them to get what we want sometime.
wayne

Wayne, Electricmanscott said it all on this issue:

true...

One of the positive things about a min/max state is that they have a state appeals board. Since the state appeals board hears nothing but appeals from local boards and you can argue the appeal yourself as a licensee the local boards quickly become reluctant to appear incompetent to the state board. This eliminates the tin pot god syndrome that can develop in one and two person inspection offices.
--
Tom

[This message has been edited by tdhorne (edited 09-01-2002).]

Was the sub panel in a building attached to the main house or detached? Was there a ufer ground at the sub panel?

To the point: two issues are raised.
First, there needs to be a fourth (ground) wire connecting the main panel with the sub-panel.
Second, the code conflicts here with common useage. The "main disconnect" breaker in a panel is not the same as what the code calls a "main disconnect." The NEC 'main disconnect" refers to the point where the utility lines ("main service") arrive at the meters. There can be no more than six meters without there being a single handle to disconnect all of them.
Everything after the meter is either a "feeder" to a sub-panel, or a "branch circuit." A sub-panel must have a disconnecting means, but this need not be at the sub-panel (it can be at the source panel). Under certain circumstances (called "tap rules") the overload protection need not be at the source.
As you can see, a journeyman is paid for his training, experience, and judgement- as well as his time. You've got to respect him for that.