6 handle rule, Services

[George Stolz]

I'm looking at this cross-eyed.

230.71(B) Single-Pole Units. Two or three single-pole switches or breakers, capable of individual operation, shall be permitted on multiwire circuits, one pole for each ungrounded conductor, as one multipole disconnect, provided they are equipped with handle ties or a master handle to disconnect all conductors of the service with no more than six operations of the hand.

I have always seen this as saying that you can tie handles together to meet the six-handle rule. Now, looking closer, it sppears that you can only exercise this option on multiwire circuits, which makes it kinda pointless. Am I misreading this, and does anyone agree that regular circuits should be allowed to be tied together to attain the six handles?

 

[infinity]

Re: 6 handle rule, Services

For 3 phase, it sounds like 18 single pole breakers with handle ties on three poles would keep you within the 6 operations of the hand.

[ June 17, 2005, 08:07 PM: Message edited by: infinity ]

 

[George Stolz]

Re: 6 handle rule, Services

But why only multiwire circuits?

We're talking about disconnecting all loads with six throws of the hand, who cares if some of the circuits share a neutral or not?

 

[iwire]

Re: 6 handle rule, Services

George I think what this section is saying is this.

You have permission to count multiple single pole units feeding multiwire branch circuits as one when the handles are linked.

I doubt the NEC wants to allow us to link all the breakers of a two wire branch circuits together for this purpose.

If you where a homeowner would you be happy to find out to kill the power to one two wire outlet circuit 2 or 3 other two wire circuits had to be killed because of linked handles?

 

[George Stolz]

Re: 6 handle rule, Services

That's a design issue.

Look at it the other way: Imagine almost all the circuits in a house pulled as mulitwires. Overload a leg of a multiwire circuit, and you have another circuit interrupted anyway. If the lights and receptacles are the black leg and the red leg, respectively, then your outlets caused the lights to go out.

That sucks, but the NEC doesn't care about that guy.

I guess I'm just bitter because I lost the argument, the other guy just might not know it yet.

 

[iwire]

Re: 6 handle rule, Services

Originally posted by georgestolz:
That's a design issue.

Yes I agree.

Originally posted by georgestolz:
Look at it the other way: Imagine almost all the circuits in a house pulled as mulitwires. Overload a leg of a multiwire circuit, and you have another circuit interrupted anyway. If the lights and receptacles are the black leg and the red leg, respectively, then your outlets caused the lights to go out.

That would depend if you used common trip breakers or single pole units with handle ties.

Handle ties are not intended to open both breakers on a trip.

Of course that is another design issue.

For what it's worth I find 230.71(B) confusing at best.

 

[infinity]

Re: 6 handle rule, Services

Look at it the other way: Imagine almost all the circuits in a house pulled as mulitwires. Overload a leg of a multiwire circuit, and you have another circuit interrupted anyway. If the lights and receptacles are the black leg and the red leg, respectively, then your outlets caused the lights to go out

I think we need to back up a bit and look at 230.70 and 230.71. The heading of 230.70 is Service Equipment-Disconnecting Means , the heading of 230.71 is Maximum Number of Disconnects . Since this section pertains to service disconnects I fail to see how this would affect multiwire branch circuits feeding lights and receptacles unless the service did not have a main.

 

[iwire]

Re: 6 handle rule, Services

Originally posted by infinity:
I fail to see how this would affect multiwire branch circuits feeding lights and receptacles unless the service did not have a main.

I think that is exactly the target of this section.

You could have a panel with no main but 18 single pole units grouped by handle ties by threes resulting in 6 throws of the hand to kill everything.

Why anyone would choose to do that escapes me.

Wait....it just struck me that the section does not mention branch circuits and a feeder to a panel is a multiwire circuit.

So I guess I have seen this, an MLO service panel with six 3 pole breakers feeding subpanels.

[ June 18, 2005, 09:51 AM: Message edited by: iwire ]

 

[George Stolz]

Re: 6 handle rule, Services

I was in a situation recently in an existing house where I originally believed there were more than 6 handles in an MLO panel serving as the service disconnect. Before I realized it was a split buss panel, where one of the upper breakers served as the disconnect for several of the branch circuits on the lower section of the panel.

Before I fully understood how it worked, I was contemplating installing handle ties to bring the entire panel to under six handles. Fortunately, it didn't come to that.

But I did get into a discussion with another RW that happened to stop by to steal my apprentice, who said I could only tie the handles together on multiwire circuits. Upon review, I agreed, then I read again after he left, and changed my mind. I bumped into him again, and said I was right. Then I came home last night, looked again and saw I was wrong.

It just seems, it complying with this section, the fact that the circuits share a neutral seems highly irrelevant, unless the section's designed to limit the application, for the design problem we've been discussing--plug in a toaster and half the house dies.

 

[jwelectric]

Re: 6 handle rule, Services

408.34 (A) Lighting and Appliance Branch-Circuit Panelboard. A lighting and appliance branch-circuit panelboard is one having more than 10 percent of its overcurrent devices protecting lighting and appliance branch circuits.

408.36 Overcurrent Protection.
(A) Lighting and Appliance Branch-Circuit Panelboard Individually Protected. Each lighting and appliance branch-circuit panelboard shall be individually protected on the supply side by not more than two main circuit breakers or two sets of fuses having a combined rating not greater than that of the panelboard.

After reading the two sections as outlined above I do believe that to tie the handles of single pole breakers together of a multiwire circuit would require that a main be placed in this panel. The fact that this panel board by definition would have more than 10 percent of its circuits employing a neutral as outlined in 408.34 ?A lighting and appliance branch circuit is a branch circuit that has a connection to the neutral of the panelboard and that has overcurrent protection of 30 amperes or less in one or more conductors."

 

[redfish]

Re: 6 handle rule, Services

2005 Code article 230.71 (A) covers the maximum number of disconnects permitted as the disconnecting means for the service conductors that supply the building or structure. </font>

• <font size="2" face="Verdana, Helvetica, sans-serif">I read 230.71(B) as saying that if you have six seperate loads to disconnect, you would need to disconnect each one with one sweep of the hand, so if one or more of the individual loads consists of two or more single pole breakers you may tie the handles in order to disconnect this load with one sweep.</font>

<font size="2" face="Verdana, Helvetica, sans-serif">Long and rambling but what do you guys think?

[ June 19, 2005, 10:26 AM: Message edited by: redfish ]

 

[jwelectric]

Re: 6 handle rule, Services

Redfish
Using the six disconnects rule is okay unless it is breakers that are in the same panel board that have handle ties.
If you had a 12 circuit panel then only one single pole breaker or Circuit could employ the use of the grounded (neutral) conductor. 10 percent of 12 is 1.2 or just one breaker.
If you had two single pole breakers with a handle tie that used a grounded (neutral) conductor then you would have more than 10 percent of the breakers that are lighting and appliance branch circuits. Now you would have to comply with:

408.36 Overcurrent Protection.
(A) Lighting and Appliance Branch-Circuit Panelboard Individually Protected. Each lighting and appliance branch-circuit panelboard shall be individually protected on the supply side by not more than two main circuit breakers or two sets of fuses having a combined rating not greater than that of the panelboard.


[ June 18, 2005, 11:35 PM: Message edited by: jwelectric ]

 

[George Stolz]

Re: 6 handle rule, Services

JW,

NEC-2002, 408.16(A), Exception No. 2: For existing installations, individual protection for lighting and appliance branch-circuit panel-boards shall not be required where such panelboards are used as service equipment in supplying an individual resi-dential occupancy.

This house was built in 1958.

Very nice reference, though! I learned something!

 

[redfish]

Re: 6 handle rule, Services

I thought we were talking about service disconnects. Here in South Texas, my service would consist of a meter,and a service disconnect(adjacent to the meter).If I chose to install an outdoor breaker box then I could disconnect it with my service disconnect.If I was installing a service on a two to six dwelling unit, I would use a meter pack with each indvidual meter having it's own disconnect. If over six meters is required, I would need to install a big main ahead of the meter pack in order to disconnect it. Thats how we do it in Texas

 

[George Stolz]

Re: 6 handle rule, Services

Redfish, the house that I was in, built in 1958 (before Ft. Collins implemented stricter guidelines on such things) had a meter socket outside, then conduit running inside to the panel.

Inside the MLO (Main Lug Only) panel, the top eight spaces were fed from the lugs. One of the breakers fed the lower bus bars. Essentially, the upper eight spaces (which housed three 2-pole breakers) were the "service disconnect."

Look at the definitions in Article 100 regarding Service Equipment, etc. Look at Article 230 again, with this in mind: Until the conductors from the Utility are interrupted by a switch or circuit breaker, you are dealing with the "Service."

The conductors inside the conduit between the meter housing and the panel inside the house I was at are called "Service Entrance Conductors." Read that definition. The Panel indoors is part of the "Service."

Around here, we install metermains that have the disconnect and meter all in one unit, but if you read some of the posts from the guys out east, they tend to be allowed to stretch 230.71(A)(1) for up to 15 feet or better into a structure. They install a meter socket outside, and then install a MDP (Main Disconnect Panel) indoors.

This distance is totally at the discretion of the AHJ. Around here, it's outside, or back-to-back, and that's all we get. In other areas, they have more leeway.

I don't think I've said this yet, so Redfish: Welcome to the Forum!

 

[redfish]

Re: 6 handle rule, Services

Thanks for the welcome and outstanding Code knowledge and input. The way I see it so far, this forum is the best and most interesting way to get familar with the Code . Thanks again for the welcome.

 

[LarryFine]

Re: 6 handle rule, Services

George is pretty close with his "east coast" rules. As with any jurisdiction, the specifics vary a bit with each inspector, but generally speaking, we're allowed up to six feet of unprotected service cable within tyhe building. Back-to-back is preferred, of ocurse.

Anything more, and we need a main breaker where the cable enters the building, typically at the meter itself. Service cable outside seems limitless. Then there's the outside panel, often used with a service upgrade with the old panel used as a junction box.

 

[jwelectric]

Re: 6 handle rule, Services

Let?s think about this for a minute George.

We were talking about using the six disconnects as the MAIN disconnecting means by tying the handles of circuit breakers together.

This must comply with 230.70 and is allowed to be up to six in .71. The top half of your box is a Power Panelboard as defined in 408.34 (B). The minute that you take more than 10% of the circuits that are 30 amp or less that employ a grounded (neutral) conductor you have made the top part a Lighting and Appliance Panelboard and being that it is on the service side of the panel would require a main disconnecting means as outlined in 230.70.

230.70 and 71 stand the same as far back as 1975. This is the oldest book I have at this time.
Your exception for existing installations is for the panelboard only and would not apply to the service main as you described on June 17, 2005 07:56 PM.

 

[iwire]

Re: 6 handle rule, Services

Mike all you have to do to get around that is fill the rest of the panel with spare OCPDs.

[ June 19, 2005, 08:19 PM: Message edited by: iwire ]

 

[jwelectric]

Re: 6 handle rule, Services

Originally posted by iwire:
Mike all you have to do to get around that is fill the rest of the panel with spare OCPs.