6 handle rule, Services

[iwire]

Re: 6 handle rule, Services

Originally posted by jwelectric:
you must have got some motor oil for Father's Day cause you sure are slick today.

Thanks and Happy Fathers day to all.

FWIW I like a single service disconnect.

 

[don_resqcapt19]

Re: 6 handle rule, Services

jw,
While in this case, because we are talking about the serivce panel, the lighting and appliance branch circuit panel overcurrent protection would have to be in the form of a main breaker, in other cases, the code does not require this OCPD to be in the lighting and appliance branch circuit panel. It can be anywhere on the line side of the panel.
Don

 

[jwelectric]

Re: 6 handle rule, Services

Yes sir Don.
This is the point I was trying to make.
The old split bus panels are very dangerous to the unskilled and sometimes the skilled electrician.
We sure don?t need to be tying single pole breakers together on the top side.

 

[George Stolz]

Re: 6 handle rule, Services

Originally posted by jwelectric:
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...

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 residential occupancy.

Uh, Mike, I think it applies inherently.

I walked in circa 2005, the house was built before my parents graduated high school. That's pretty "existing" to me, regardless of what happened in 1958.

[ June 20, 2005, 08:14 AM: Message edited by: georgestolz ]

 

[allenwayne]

Re: 6 handle rule, Services

It`s amazing to see how different parts of the usa have come along electrically.I recentley did a friend a favor he was selling his home circa 1970 and the home inspector cited incoming feeder from meter was burned and needed to be replaced no big deal This was in an old sub division and there was a MLO panel and a meter that was it no disconnect !!!.cut the seal replaced the all the incoming and called for a meter reseal.I was puzzled no disconnect As fae as I can remember there has always been a main from the meter to the panel either besides it for a remote or back to backed on a MBR panel.Has anyone else encountered this ????

 

[bearwires]

Re: 6 handle rule, Services

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?

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.

Unless it's an ungrounded delta service all services should have a ground and/ or a grounded
conductor as part of the service configuration making it a multi wire system, which should be carried through out the feeders and branch circuits.

210.4 Multiwire Branch Circuits.(B) Dwelling Units. In dwelling units, a multiwire branch circuit supplying more than one device or equipment on the same yoke shall be provided with a means to disconnect simultaneously all ungrounded conductors at the panelboard where the branch circuit originated.

210.7 Branch Circuit Receptacle Requirements.
(C) Multiple Branch Circuits. Where more than one branch circuit supplies more than one receptacle on the same yoke, a means to simultaneously disconnect the ungrounded conductors supplying those receptacles shall be provided at the panelboard where the branch circuits originated.

In 210.7(C), specifying a means to simultaneously disconnect the ungrounded conductors is a safety issue that applies to devices (actually, the single yoke) where more than one branch circuit is involved. NEC HANDBOOK

We have to remember what the NFPA stands for in NFPA 70, Not only is to prevent fires. It is also for the saftey of those who fight them And for the people who maintain electrical systems(professionals and Joe home owners espesially Joe home owner).
So when some one says "The breakes is off" they have a resanable epectation it is. (but i always check first )

 

[jwelectric]

Re: 6 handle rule, Services

George

I am going to try as best as I can to explain this. I hope that some of the old-timers will jump in and help me out just a little.

The exception that you have pointed to is a classic case of needing to know past editions of the code in order to understand the present issues. It was found in 384-16 from pre 1975 through 1999 and moved to 408.16 in 2002. It is now found in 408.36 of the 2005.

From the dawning of the electrical age we have been required to have a main disconnecting means.
As electrical services evolved from the two cartridge fuse main to the breaker stage came the birth of the Split-Bus panel.
This panel allowed us to use one breaker as the disconnect for the bottom half of the panel and the rest for any 240 volt two pole circuit such as well, range, water heater or air conditioner. The wording found in 408.14 of the 2002 and 384-14 of prior editions of the NEC stated that there could be no more than 10% of the circuits feeding a 30amp or less load that also used the neutral there fore the dryer could not be wired on this side of the panel.

As time rolled on and the mighty Mississippi reached eternally for the sea mankind (the NFPA) saw the danger in the split bus panel and outlawed them. Here is the insert from the 2002 Handbook that explains this a little better.

-The phrase ?for existing installations? in Exception No. 2 refers to the existing panelboard. It is not intended that a split-bus panelboard used in an individual residential occupancy be replaced if a circuit is added to the existing panelboard. It does mean, however, that for the installation of new panelboards in new or existing residential occupancies, a split-bus six-disconnect panelboard (with more than two circuit breakers or sets of fuses protecting the panelboard) is not permitted for the service equipment.
An individual residential occupancy could be a dwelling unit in a multifamily dwelling where the panelboard is used as service equipment. See the definition of dwelling unit in Article 100.

These are the same words that are printed in the 2005 Handbook. I hope this helps you as well as others understand why we CAN?T tie the handles of single pole breakers to fulfill the six disconnect rule.