Insualted Equipment Grounding Conductor

[fmtjfw]

And I go back to this....
90.1 Purpose.(A) Practical Safeguarding. The purpose of this Code is the practical safeguarding of persons and property from hazards arising from the use of electricity.

So you interpret 90.1(A) as only applying to users of electricity, not to electricians when they are practicing the trade. I interpret it to apply to everyone in all circumstances. We can agree to disagree.

The stated purpose is fulfilled without any rule for using handle ties or three pole breakers. MWBCs present no hazard to anyone using them. The '08 code change moved beyond that purpose to safeguarding bozos working on them. Yea, that's what we need more rules geared toward guys like the fella in your example. Let's do all we can to keep them afloat in the trade.

Like it or not, there are a whole bunch of persons employed as electricians who

(1) don't understand the hazard of opening a shared neutral in a MWBC without removing voltage from all the ungrounded conductors in the MWBC.

(2) don't possess the mystical powers of figuring out all the ungrounded wires' OCPDs while standing at a pre-2008-rules panelboard. I still have not been shown a method that will reliably indicate that without me having to find outlets on each of the hot wires in the MWBC. I'll not even ask for a method of finding the common neutral conductor's termination at the panelboard.

With the 2014 rules I can just walk up to a panelboard and see by the grouped breakers (handle ties or common trip) and / or by the conductor grouping what conductors are in a MWBC.

I'm all for getting the bozos out of the trade. Then I would not have to worry so much about what I may find. I would like to see license testing that included a demonstration of manual skills, continuing education requirements at least for new code cycles, and periodic retesting. I would also like to see a scheme for complaints against licensed electricians that included retraining as an option, rather than the current -- keep your license or lose your license, since taking away a persons livelihood is a serious step (and only done under extreme conditions).

I worked for almost 2 years, to no avail, to get an electrician I worked with either dismissed or trained and certified as having attained the necessary skills not to endanger me with his non-Code compliant work. He was offered a free, work time 9 month course which he refused to take after doing very poorly on the entrance test. He, like I, was a military veteran, but he played the "Veteran" card to excuse all his screw ups. And the bosses took it, hook, line, and sinker. [He had skipped the requirements for sitting for the journeyman's test by playing the veteran's card and went to a cram school (we'll keep pounding the likely test answers into your head until you manage to pass).]

I used to bounce MWBC all over the panel, I didn't, and still don't see it as a problem.

You will need to excuse my extreme ignorance. I have never worked under an NEC version that did not require:

210.4 Multiwire Branch Circuits.
....
(B) Disconnecting Means.
Each multiwire branch circuit shall be provided with a means that will simultaneously disconnect all ungrounded conductors at the point where the branch circuit originates.

It has only been in effect for 3 code cycles, but I guess the "training wheels" are still a sore point for some.

You are free to question my intelligence, I won't be offended. I don't think it is much above average, if at all. I struggle with basic math, couldn't tell the first thing about the magic that makes electrical stuff work once the discussion moves beyond circuitry and wires, shoot man, I can't make a post without using spell check on words with more than five letters.

I can figure out which breakers I need to turn off when working on MWBCs. Depending on where I am working on the circuit I may only need to turn one breaker off and still keep me and any equipment safe. Stupid handle tie rule makes that impossible.

You have a good point, can we come up with a reliable scheme for handle ties that will normally turn off all the breakers tied with the tie and also allow a single breaker to be turned off while leaving the other(s) on. Come to think of it, if the handle tie was supported by a hinge at each end and was placed outside the breaker handles on the "ON" side you could operate it to turn them all off meeting 210.4(B). You could also operate a single breaker to the off position. This would not give you a method for turning them all on at the same time, but that is not required.

I don't question anybody's intelligence if they don't know which breakers to turn off just because they are not grouped. I do question their qualifications.

See above about reliable method.

I resent code mandated training wheels like 210.4(B). They weaken the quality of the trade rather than elevating the importance of education, training, and skill.

 

[petersonra]

If the handle tie is a problem while troubleshooting, how about you just take it out and put it back in when you are done?

 

[iwire]

If the handle tie is a problem while troubleshooting, how about you just take it out and put it back in when you are done?

Some you can, others require pulling the breakers out which would be prohibited hotwork unless you kill the panel.

This demonstrates one of the problems the people making the rules no matter how intelligent or knowlegable they may be are not in the field doing the work. They assume things without really knowing.

 

[don_resqcapt19]

...
You have a good point, can we come up with a reliable scheme for handle ties that will normally turn off all the breakers tied with the tie and also allow a single breaker to be turned off while leaving the other(s) on. Come to think of it, if the handle tie was supported by a hinge at each end and was placed outside the breaker handles on the "ON" side you could operate it to turn them all off meeting 210.4(B). You could also operate a single breaker to the off position. This would not give you a method for turning them all on at the same time, but that is not required.
....

If it is going to be easy to operate one breaker at a time, why have the rule. Just go back to the older codes when this was not a rule.

The rule also as an "anti-green" effect. Because of this rule more designers are prohibiting MWBC requiring the use of more copper and increasing the system losses.

 

[ActionDave]

So you interpret 90.1(A) as only applying to users of electricity, not to electricians when they are practicing the trade. I interpret it to apply to everyone in all circumstances. We can agree to disagree.



Like it or not, there are a whole bunch of persons employed as electricians who

(1) don't understand the hazard of opening a shared neutral in a MWBC without removing voltage from all the ungrounded conductors in the MWBC....

But there are a whole bunch of us who do. I see no reason to lower standards and drag the whole trade down.

I like the idea of better training, evaluations, and continuing ED. Where we are headed now to me feels like a world where these are being replaced by more and more rules that cover for lack of them.

 

[fmtjfw]

If it is going to be easy to operate one breaker at a time, why have the rule. Just go back to the older codes when this was not a rule.

The rule also as an "anti-green" effect. Because of this rule more designers are prohibiting MWBC requiring the use of more copper and increasing the system losses.

No one has convinced CMP 2 remove the rule. If it is such a problem and you guys are opposed to it, just write up a change and substantiation.
It's free, and who knows you might succeed.

I am a great proponent of MWBCs:

1) they use less copper
2) they have lower losses than equivalent individual neutral circuits
3) more capacity fits into the same conduit
a) fewer conductors
b) less reduction in ampacity due to fewer CCCs.

That said, I know of no company failing due to the cost of handle ties.

 

[don_resqcapt19]

No one has convinced CMP 2 remove the rule. If it is such a problem and you guys are opposed to it, just write up a change and substantiation.
It's free, and who knows you might succeed.

I am a great proponent of MWBCs:

1) they use less copper
2) they have lower losses than equivalent individual neutral circuits
3) more capacity fits into the same conduit
a) fewer conductors
b) less reduction in ampacity due to fewer CCCs.

That said, I know of no company failing due to the cost of handle ties.

Rules like this that has a "safety" substantiation are almost never removed from the code.
As far as the advantages of MWBCs, yes I fully agree, but because of the "handle tie" rule, many designers now prohibit the use of them.

 

[iwire]

So you interpret 90.1(A) as only applying to users of electricity, not to electricians when they are practicing the trade.

It should apply to each group at that groups level of training. Most users of electricity have no training in it. Qualified people have training to do the tasks assigned to them.

Like it or not, there are a whole bunch of persons employed as electricians who

(1) don't understand the hazard of opening a shared neutral in a MWBC without removing voltage from all the ungrounded conductors in the MWBC.

So your solution to that real and serious problem is to add a rule that the knowledge people will have to follow and this group of untrained will not understand, not apply and still not understand the danger.

That is a poor solution.

(2) don't possess the mystical powers of figuring out all the ungrounded wires' OCPDs while standing at a pre-2008-rules panelboard. I still have not been shown a method that will reliably indicate that without me having to find outlets on each of the hot wires in the MWBC. I'll not even ask for a method of finding the common neutral conductor's termination at the panelboard.

You are trying to make a simple task into much more than it is. I have been doing this task for about 30 years and it is not that bad. Each situation is different, sometimes it goes quick, sometimes not. But when did the NECs purpose become 'Make it easy'?

With the 2014 rules I can just walk up to a panelboard and see by the grouped breakers (handle ties or common trip) and / or by the conductor grouping what conductors are in a MWBC.

Can you? You have gone on at length in this thread about how so many electricians don't understand MWBCs now you want to count on these same folks to install and label them correctly.

I would like to see license testing that included a demonstration of manual skills, continuing education requirements at least for new code cycles, and periodic retesting. I would also like to see a scheme for complaints against licensed electricians that included retraining as an option, rather than the current -- keep your license or lose your license, since taking away a persons livelihood is a serious step (and only done under extreme conditions).

I am required to take 21 hours every code cycle in MA, 15 hours every code cycle in RI, 4 hours every year in CT. All three states have ways to report electricians to the licensing boards. Yet we are all stuck with the NEC moving toward helping the DIYs.

I worked for almost 2 years, to no avail, to get an electrician I worked with either dismissed or trained and certified as having attained the necessary skills not to endanger me with his non-Code compliant work. He was offered a free, work time 9 month course which he refused to take after doing very poorly on the entrance test. He, like I, was a military veteran, but he played the "Veteran" card to excuse all his screw ups. And the bosses took it, hook, line, and sinker. [He had skipped the requirements for sitting for the journeyman's test by playing the veteran's card and went to a cram school (we'll keep pounding the likely test answers into your head until you manage to pass).

Call me doubtful.

You will need to excuse my extreme ignorance. I have never worked under an NEC version that did not require:

210.4 Multiwire Branch Circuits.
....
(B) Disconnecting Means.
Each multiwire branch circuit shall be provided with a means that will simultaneously disconnect all ungrounded conductors at the point where the branch circuit originates.

That explains a lot of your fears of them.

but I guess the "training wheels" are still a sore point for some.

Yes, poor code changes irk me, but I will abide by them.

No one has convinced CMP 2 remove the rule.

And no one will, it is water under the bridge. Yet I and others don't have to like it. I think we are entitled to our opinions.

I am a great proponent of MWBCs:

1) they use less copper
2) they have lower losses than equivalent individual neutral circuits
3) more capacity fits into the same conduit
a) fewer conductors
b) less reduction in ampacity due to fewer CCCs.

I was as well, first thing I would do with new prints was figure out what circuits I could make MWBC homeruns out of. I used to always carry 12/4 cable to make home runs on service calls. Now it is pretty much all two wire circuits. Our customers will not be impressed if a short on one leg takes one or two other circuits. (Even trip free it is a crap shoot if the handle tie trips the other breakers) The customer would not want the inconvenience of having to shut off equipment X and Y so I can work on equipment Z.

I know of no company failing due to the cost of handle ties.

And no one in this thread has pointed to the cost of handle ties being any part of the problem.