dual voltage from ocpd,referencing an old post.

[hurk27]

Re: dual voltage from ocpd,referencing an old post.

BY steve: The problem is that you are using equipment that is not listed for use. You would be trying to protect (OCP) a single phase 120V circuit with a double pole breaker. Not listed for use, and definitely not workmanlike manner

Steve if this were true then we could not use the 2-pole AFCI's that they developed just for exsiting bedrooms that have a shared neutral run to them. And yes they are UL listed for that purpose! as the receptacle that was posted IT IS UL LISTED for shuch use! go the UL's web site and look it up. I would do it for you but I have to get to my IAEI meeting.

[ July 05, 2005, 05:34 PM: Message edited by: hurk27 ]

 

[hurk27]

Re: dual voltage from ocpd,referencing an old post.

Steve I do have a code section:

210.4(C) Line-to-Neutral Loads. Multiwire branch circuits shall supply only line-to-neutral loads.

This say's I can only supply line to neutral load's

BUT!

Exception No. 2: Where all ungrounded conductors of the multiwire branch circuit are opened simultaneously by the branch-circuit overcurrent device.

This say's If I open all the ungrounded conductors by the breaker I can do it!

The only way to open all the ungrounded conductors is by a two pole breaker.
If you can't see this then you are saying this exception was a mistake? with out this exception all 120/240 circuits in a building would be in violation. EVEN THE MAIN BREAKER IN THE SERVICE!

 

[roger]

Re: dual voltage from ocpd,referencing an old post.

Wayne,

Roger

 

[don_resqcapt19]

Re: dual voltage from ocpd,referencing an old post.

Steve,

That is something that should be common sense to someone that understands the basic principles of electricity.

What hazard or safety issue is caused by the use of this type of circuit?
Don

 

[hurk27]

Re: dual voltage from ocpd,referencing an old post.

Wayne, you can't use that because Steve is tired of being made aware that it is in the NEC.

Oh I'm sorry, Did his city eliminate exception 2 to 210.4?

If they did I wonder how they pass a service main (2-pole) because it also feeds 120 volt circuits?

 

[milwaukeesteve]

Re: dual voltage from ocpd,referencing an old post.

What you guys are missing is that Multiwire branch circuits ARE legit. BUT that means only multiwire branch circuits.

You guys keep citing the same reference - exception #2 - but that doesn't explain or allow this type of installation.

You still cannot share a Phase conductor for 2 different types of loads (240/120). Don, Iwire, if you want what the harm is, I just explained that in my last reply.
Exception #2 allows you to group conductors in a multiwire brance circuit, providing that you handletie all phase conductors (all 3 poles for 120v and the 240or208V). I doesn't say anything about putting 2 different circuits on the same pole of breaker. It doesn't say anything about sharing a phase conductor for 2 different circuits. It doesn't say anything about combining 2 different types of circuits.

If the NEC doesn't say you CAN do something, what says then that you CAN'T do something. That arguement is always used in reverse to make your points, but I am going to use it now for MY arguement. I at least have common sense, safety, workmanlike manner and Electric theory on my side to make that arguement.

The NEC doesn't address your particular point, so is it something you can do since your not told otherwise, or something you can't do. If it is not specifically addressed, then this is where we look outside the NEC.

 

[iwire]

Re: dual voltage from ocpd,referencing an old post.

Steve we all have been patient trying to help you out with this. You refuse to see what is in front of you. You are stuck with just your personal dislike of this circuit.

Originally posted by milwaukeesteve:
What you guys are missing is that Multiwire branch circuits ARE legit. BUT that means only multiwire branch circuits.

That is what we are talking about, you have this preconceived idea that multiwire branch circuits can only be used in one way.

Your mistaken

Originally posted by milwaukeesteve:
You guys keep citing the same reference - exception #2 - but that doesn't explain or allow this type of installation.

Steve again you are mistaken, that is exactly what the section allows

Please explain what exception #2 allows in your mind.

Originally posted by milwaukeesteve:
You still cannot share a Phase conductor for 2 different types of loads (240/120).

That is clearly your opinion but again your mistaken

Originally posted by milwaukeesteve:
Don, Iwire, if you want what the harm is, I just explained that in my last reply.

You mean this?

Originally posted by milwaukeesteve:
Iwire, you talk about what the harm is, and also what the difference is between this and a dryer or a range.
The difference is that the dryer has fixed components with no variables. The light on the inside isn't suddenly going to change. Yet, when you have something like this well pump/sump pump thing, there are variables that can change. That is where the safety and/or nuisance tripping or other potential hazards can happen.

What have you explained here?

I agree in a dryer there are fixed loads we agree there.

However back to the combination receptacle I posted. How is the chance of overload any greater for this combination receptacle than a typical small appliance circuit.

Originally posted by milwaukeesteve:
If the NEC doesn't say you CAN do something, what says then that you CAN'T do something. That arguement is always used in reverse to make your points, but I am going to use it now for MY arguement.

Would you like to try that again in plain English? strange I have not seen one person jump in to support you here.

I will try one last time.

You have mentioned 'electrical theory' a number of times in this thread.

Can you please explain how this circuit and electrical theory clash?

Can you also explain why this is not a 'workmanlike' circuit?

And finally can you explain the safety hazard in this circuit.

The possibility for overload is not a safety hazard, any receptacle circuit has the potential to be overloaded, thats why we install overcurrent protection.

By the way (and Mike pay attention ) this wiring diagram I posted earlier

 

[milwaukeesteve]

Re: dual voltage from ocpd,referencing an old post.

A circuit cannot have 2 possible return paths. When you combine two different circuits like this, you are creating a possibility of a return path for electricity that is not designed, nor is correct.

For example: (and I need to do this without the aid of drawings)
If you had the 9A pump and the 9A pump and the circuit trips on overload, theoretically (since all handles are tied together) all breaker poles will trip.
What if the opposite pole doesn't trip internally, since you are only overloading one phase. Now you have 120v from the other pole with a return path that runs through BOTH motors (in series).
Is that what you want? What about your window A/C unit and a Vacuum Cleaner? What about the window A/C and your computer? Which do you suspect would take the most damage?

There is your Basic Electric Theory argument.
There is also a safety argument.
There is also a workmanlike manner because we should know better than to install something like that.

Are you going to trust an FPE, or a Zinsco, or a Pushmatic to actually break both poles on an overload of just one of the poles?

 

[milwaukeesteve]

Re: dual voltage from ocpd,referencing an old post.

If you are asking me what code rules apply to my argument, I will ask you the same thing.

What code rules tell you that you can do this? Since you keep saying nothing says you can't, show me where it says you CAN.
(210.4 (C)exception #2 does not count)
That rule only states that all ungrounded conductors in a MWBC must be handletied together. It says nothing about sharing a common phase conductor for 2 different types of loads.

Show me a code reference that supports your side.

 

[iwire]

Re: dual voltage from ocpd,referencing an old post.

Originally posted by milwaukeesteve:
If you had the 9A pump and the 9A pump and the circuit trips on overload, theoretically (since all handles are tied together) all breaker poles will trip.
What if the opposite pole doesn't trip internally, since you are only overloading one phase.

That is why the NEC requires internal common trip breakers be used in this application, handle ties are not enough.

The same thing could happen on a straight 240 load if one phase ground faults, only one pole would trip if it was not an internal common trip breaker.

Originally posted by milwaukeesteve:
There is your Basic Electric Theory argument.
There is also a safety argument.
There is also a workmanlike manner because we should know better than to install something like that.

Are you going to trust an FPE, or a Zinsco, or a Pushmatic to actually break both poles on an overload of just one of the poles?

Yes I trust that an electrical product used within it's design is a safe installation.

The NEC assumes breakers will work as designed.

If we disallow this particular installation because the internal common trip breaker may not function correctly then we might as well stop installing all electrical equipment. :roll:

 

[peter d]

Re: dual voltage from ocpd,referencing an old post.

Steve,

You are just banging your head against the wall. There are no NEC rules that forbid this, so therefore it is allowed.

Let me share a native American proverb with you:
"There is no man so blind as the one who does not see."

As Bob and others have suggested, take the blinders off, remove your personal dislike and bias towards this type of installation, and you will see quite plainly that this is a perfectly code compliant installation.

 

[jwelectric]

Re: dual voltage from ocpd,referencing an old post.

I can?t take it any longer. I NEED HELP!!!!!!

If I buy me an outside storage building am I going to have to run multiple circuits to this building if I want 120 and 240?

Can I install a 60 amp subpanel and use 240 and 120 out of it?

I don?t want to install but one neutral. How can this be done?

Is this 60 amp breaker that is protecting the feeders the same thing that you are talking about with the exception that they are feeders?

 

[milwaukeesteve]

Re: dual voltage from ocpd,referencing an old post.

jw, no this is not the same.
The 60 Amp feeder that you send out there is 240V/120V, just like the service on your house but smaller.
The distribution breakers are what protect the individual circuits.

In the example that some are not quite seeing right, there is no individual protection for the individual circuits. They are sharing one pole of a 2pole breaker, and sharing one phase conductor for 2 different purposes.

 

[iwire]

Re: dual voltage from ocpd,referencing an old post.

Originally posted by milwaukeesteve:
In the example that some are not quite seeing right, there is no individual protection for the individual circuits. They are sharing one pole of a 2pole breaker, and sharing one phase conductor for 2 different purposes.

Steve I see it just fine and I am sure the others do to.

Steve sharing one phase conductor for 2 different purposes is a very common thing to do.

If I have two 14/2 home runs to a panel, one circuit feeds lights one circuit feeds receptacles. I decide to pigtail these together under one breaker.

It could be overloaded at some point and it is serving different purposes.

Now apply that to a one pole of a breaker feeding one side of both 120 and 240 loads.

Electrically it is the same thing, it is not unsafe and it is allowed.

We should probably leave feeders out of this thread they are not covered by Article 210.

 

[roger]

Re: dual voltage from ocpd,referencing an old post.

Steve, you really are being ridiculous and showing just how badly you hate being proven wrong. You have been shown the applicable code article, devices that are listed for the purpose, examples of this type of circuit and/or feeder, and even a diagram from the handbook that allows it, yet you refuse to admitt what is in black and white.

Your argument is becoming sad. Sorry for being so blunt.

Roger

 

[milwaukeesteve]

Re: dual voltage from ocpd,referencing an old post.

This IS getting rediculous!
I am asking you guys again. Show me where you state this is a good way to do wiring.

Bob, pigtailing several conductors to one breaker is not the same thing. What we are talking about here is feeding 2 different TYPES of loads from one single branch circuit device.

Nowhere in the code does it say you can do this.

Roger, that last comment wasn't nice. I am trying to make a point based on valid reasons. I am not just showing my bias against this type of wiring. I am and have spent several long replies trying to explain something. So far the other side has not except for 'since it doesn't say you can't then you can.' That is not a valid argument in my book.

Can I lay a screwdriver across 2 phases in the switchgear? The NEC doesn't say you can't do it, then why can't I. Because you just don't.

 

[roger]

Re: dual voltage from ocpd,referencing an old post.

Steve, your not even rational in your defense.

Originally posted by milwaukeesteve:

Can I lay a screwdriver across 2 phases in the switchgear? The NEC doesn't say you can't do it, then why can't I. Because you just don't.

I rest my case.

Roger

 

[iwire]

Re: dual voltage from ocpd,referencing an old post.

Originally posted by milwaukeesteve:
This IS getting rediculous!

You are right it is ridiculous.

As Roger has pointed out you have been shown everything and all you can seem to come up with is not workmanlike. :roll:

You are wrong plain and simple.

Bob

 

[peter d]

Re: dual voltage from ocpd,referencing an old post.

Steve, the NEC is about life safety, not what you deem to be "good wiring practice."

Again, how is this installation unsafe and a threat to life safety?

 

[don_resqcapt19]

Re: dual voltage from ocpd,referencing an old post.

Steve,

Is that what you want? What about your window A/C unit and a Vacuum Cleaner? What about the window A/C and your computer? Which do you suspect would take the most damage?

Unless the neutral is also open, the only thing that will happen is the 240 volt load will stop working and the 120 volt load will continue as normal. There is no series path because one breaker pole is open. Yes there will be 120 volts on the load side of this breaker, but no current flow because there is no path. There is no hazard with this type of circuit. It may not be desirable from a design standpoint, but there is no safety hazard or code violation.
Don

My comment above is not correct in all cases. If the OCPD that serves the 120 volt loads opens, there is a series path and possible equipment damage, however, the code requires a common trip device to prevent this problem.

[ July 06, 2005, 11:03 PM: Message edited by: don_resqcapt19 ]