Insualted Equipment Grounding Conductor

[mstrlucky74]

It also has the advantage that the 3-pole breakers are more expensive than 3 1-pole breakers and 1 3-pole handle tie.

I don't think it's much more expensive

 

[Smart $]

I don't think it's much more expensive

Probably twice the cost, or more.

 

[augie47]

Most folks in this area shy away from MWBC on lighting circuits now with the "new" requirements. With the handle ties or a multi-pole breaker, a short in any fixture or circuit or a need to turn off only one circuit by means of the breaker results in a loss of a lot of light.
With a 277v system you can end up with a whole bunch of fixtures that go dark due to one ballast shorting.

 

[ActionDave]

Most folks in this area shy away from MWBC on lighting circuits now with the "new" requirements. With the handle ties or a multi-pole breaker, a short in any fixture or circuit or a need to turn off only one circuit by means of the breaker results in a loss of a lot of light.
With a 277v system you can end up with a whole bunch of fixtures that go dark due to one ballast shorting.

Stupid, stupid new rule. One code change makes a hundred years of safe wiring a bad choice instead of an elegant, cost effective one.

 

[iwire]

Stupid, stupid new rule. One code change makes a hundred years of safe wiring a bad choice instead of an elegant, cost effective one.

Yes, changes made to help the unqualified. It will only get worse, one way or the other I only have 4 more code cycles to worry about.

 

[mstrlucky74]

So using a 3p breaker for 3 separate circuits(as in this case) is a MWBC,correct? They share the same neutral.

if it were one motor utilizing a 3p breaker it would not be a MWBC.

i thought this was a good explanation although very basic for many of you.

http://www.homeinspector.org/resources/journals/Multiwire-Branch-Circuits.pdf

 

[Smart $]

So using a 3p breaker for 3 separate circuits(as in this case) is a MWBC,correct? They share the same neutral.

if it were one motor utilizing a 3p breaker it would not be a MWBC.

...

Yes.

There are other instances of is and not, but no need to complicate the discussion.

 

[fmtjfw]

Most folks in this area shy away from MWBC on lighting circuits now with the "new" requirements. With the handle ties or a multi-pole breaker, a short in any fixture or circuit or a need to turn off only one circuit by means of the breaker results in a loss of a lot of light.
With a 277v system you can end up with a whole bunch of fixtures that go dark due to one ballast shorting.

With handle ties on 3 1-pole breakers it is not likely that a single breaker tripping would trip either or both of the other two breakers. The trip-free feature of the breaker that tripped would probably not have enough energy applied to the handle for that to happen.

Stupid, stupid new rule. One code change makes a hundred years of safe wiring a bad choice instead of an elegant, cost effective one.

No code rule against MWBC that I know of.

Yes, changes made to help the unqualified. It will only get worse, one way or the other I only have 4 more code cycles to worry about.

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.

Handle ties are practical and add a level of safety.

 

[Smart $]

...

Stupid, stupid new rule. One code change makes a hundred years of safe wiring a bad choice instead of an elegant, cost effective one.

No code rule against MWBC that I know of.

...

I think the issue being called stupid is the requirement for handle ties... but there is nothing preventing the use of a wall switch to de-energize only one branch of the MWBC.

 

[GoldDigger]

I think the issue being called stupid is the requirement for handle ties... but there is nothing preventing the use of a wall switch to de-energize only one branch of the MWBC.

And that would be fine to the extent that even an inexperienced electrician should not be using that switch to deenergize the circuit before working on it.

 

[iwire]

Handle ties are practical and add a level of safety.

Handle ties are to aid the idiots doing electrical work. They make servicing MWBCs much more of a problem. It was hard enough trying to turn off a single 277 volt lighting circuit due to the large number of fixtures connected to it. Now it is three times as many fixtures.

It also meant we could no longer make a MWBC out of say circuits 1, 10, and 17 which was very common, safe and handy.


It was unnecessary change with no real substantiation provided.

 

[fmtjfw]

I think the issue being called stupid is the requirement for handle ties... but there is nothing preventing the use of a wall switch to de-energize only one branch of the MWBC.

Handle ties only cost a few bucks. I once saw the same electrician open the MWBC neutral on 120/208Y and blow up about 6 electronic items twice in the span of 2 weeks. He was a grandfathered master electrician and was convinced he knew everything there was to know. 90% of the buildings he worked had MWBC of 120/208 and 277/480. Handle tying all the MWBCs in the building would have cost less than what he destroyed.

It would also prevent him from being shocked on a floating neutral (which he richly deserved).

Unfortunately there are a lot of electricians who quit learning on or before they completed their apprenticeship or formal training. And there are a lot of electricians working today who don't understand MWBCs, Sad, But True.

 

[ActionDave]

Handle ties are to aid the idiots doing electrical work. They make servicing MWBCs much more of a problem. It was hard enough trying to turn off a single 277 volt lighting circuit due to the large number of fixtures connected to it. Now it is three times as many fixtures.

It also meant we could no longer make a MWBC out of say circuits 1, 10, and 17 which was very common, safe and handy.


It was unnecessary change with no real substantiation provided.

:thumbsup::thumbsup::thumbsup:

 

[iwire]

Handle ties only cost a few bucks.

The cost of the handle tie is not the issue.

I once saw the same electrician open the MWBC neutral on 120/208Y and blow up about 6 electronic items twice in the span of 2 weeks. He was a grandfathered master electrician and was convinced he knew everything there was to know. 90% of the buildings he worked had MWBC of 120/208 and 277/480. Handle tying all the MWBCs in the building would have cost less than what he destroyed.

And this means what? That because he was an idiot the rest of us should have to change how we work?

Unfortunately there are a lot of electricians who quit learning on or before they completed their apprenticeship or formal training. And there are a lot of electricians working today who don't understand MWBCs, Sad, But True.

Changing code rules is no way to fix the problem of people not knowing their job.

 

[fmtjfw]

Handle ties are to aid the idiots doing electrical work. They make servicing MWBCs much more of a problem. It was hard enough trying to turn off a single 277 volt lighting circuit due to the large number of fixtures connected to it. Now it is three times as many fixtures.

It also meant we could no longer make a MWBC out of say circuits 1, 10, and 17 which was very common, safe and handy.


It was unnecessary change with no real substantiation provided.

OK, so you make a MWBC out of 1, 10, & 17. How am I, a person who understands MWBCs, supposed to know what to turn off when I need to cut a shared neutral to add a connection? I might wonder about the intelligence of an electrician who would use such a breaker "grouping".

Fixtures to turn off: 277 is most likely florescent lighting. I suppose that now you are going to tell me that the use of little pluggable disconnects in fluorescent fixture is also dumbing down the trade. If not, they are the solution to not turning off any of the lamps except the one(s) you are working on.

 

[iwire]

OK, so you make a MWBC out of 1, 10, & 17. How am I, a person who understands MWBCs, supposed to know what to turn off when I need to cut a shared neutral to add a connection?

Do you own a meter? Do you know how to use it?

I might wonder about the intelligence of an electrician who would use such a breaker "grouping".

Wow, insulting a very large group of electricians you have never met, a bold move.

Fixtures to turn off: 277 is most likely florescent lighting. I suppose that now you are going to tell me that the use of little pluggable disconnects in fluorescent fixture is also dumbing down the trade.

Well, they are a dumbing down of the trade and the fact is I don't feel comfortable plugging in and unplugging these cheesy little disconnects on live circuits particularly 277 volt ones. Once these things start aging and becoming brittle we will see a rise in burn injuries. I prefer to kill the power to the fixture. I might get behind the concept if they required a switch of some sort in place of the junk plastic plugs.

 

[fmtjfw]

Goodbye

Goodbye

Do you own a meter? Do you know how to use it?

What do you think? I am getting tired of your gratuitous insults.

Wow, insulting a very large group of electricians you have never met, a bold move.

I consider it unintelligent to leave a trap for the next electrician in the form of a MWBC scattered through out a panelboard.

Well, they are a dumbing down of the trade and the fact is I don't feel comfortable plugging in and unplugging these cheesy little disconnects on live circuits particularly 277 volt ones. Once these things start aging and becoming brittle we will see a rise in burn injuries. I prefer to kill the power to the fixture. I might get behind the concept if they required a switch of some sort in place of the junk plastic plugs.

Then I guess that you don't follow the NFPA70E Rules when working on a hot circuits. There is generally not enough energy at such a disconnect to burn through a set of goatskin protectors and meterman's rubber gloves.

Unfortunately, you are immune to the "ignore list" function, so I'll do it manually.

 

[ActionDave]

I once saw the same electrician open the MWBC neutral on 120/208Y and blow up about 6 electronic items twice in the span of 2 weeks. He was a grandfathered master electrician and was convinced he knew everything there was to know. 90% of the buildings he worked had MWBC of 120/208 and 277/480. Handle tying all the MWBCs in the building would have cost less than what he destroyed..

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.

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.

OK, so you make a MWBC out of 1, 10, & 17. How am I, a person who understands MWBCs, supposed to know what to turn off when I need to cut a shared neutral to add a connection? I might wonder about the intelligence of an electrician who would use such a breaker "grouping".....

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

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.

I consider it unintelligent to leave a trap for the next electrician in the form of a MWBC scattered through out a panelboard.

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.

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.

 

[iwire]

What do you think? I am getting tired of your gratuitous insults.

Interesting, you have no problem questioning my intelligence and the intelligence of a great many other electricians but you feel insulted if I ask you if you have a meter.

It seemed like a fair question as you stated you did not know how to identify circuit conductors.

Then I guess that you don't follow the NFPA70E Rules when working on a hot circuits. .

Well you guess wrong, but there is no requirement to wear gloves or PPE when there are no live exposed parts. If it was 'hot work' there would be no allowance to do it PPE or not. If I was to break safety rules the company I work for will either give me unpaid time off or terminate me.

Do you know what a experiance mod rating is? The company I work for has a very low Mod rating and they take safety very serious.

http://en.m.wikipedia.org/wiki/Experience_modifier

 

[don_resqcapt19]

...
Unfortunately there are a lot of electricians who quit learning on or before they completed their apprenticeship or formal training. And there are a lot of electricians working today who don't understand MWBCs, Sad, But True.

Why should that become a code rule placing a burden on the "real" electricians?

The handle tie rule accomplished exactly the opposite of what it was intended to do. That is there are more lighting circuits worked on while energized now that before that rule.