Looped Power Feed?

[romex jockey]

Tupperware containers. Its not until recently their regs required metal consumer units where they all gripe about a long needed improvement. Wire bending space requirements are still lacking, we took care of that in 1984, even though at the time our panels still had more wire bending space then they do now.

BS are basically IEC standards

NEC takes the IEC a step further (as least we've some initiative)

Their annual Earth Loop Impedance testing would be mandatory here as well, were we to install to such flimsy specifications

This is why under the NEC , where we built it right the first time, it becomes an opinion

~RJ~

 

[romex jockey]

You’ll wait a very long time.

And you'd be goose steppin' to work this morning w/o 'Septics' Mr. Tony

but hey, this country's used to ingrates

seems we collect 'em....

~RJ~

 

[Dennis Alwon]

Maybe it would have been if I would have cited it, but I doubt it. Someone would have to pay for a fact finding report done by someone like UL for my proposal to pass, and that is not likely to happen.

]]


In past years I have experience this ring circuit a few times. I never saw a problem with it but they ran the loop to two breakers on the same phase. My guess is that this was unintentional since it was only one circuit and the house was relatively small.

 

[iwire]

In past years I have experience this ring circuit a few times. I never saw a problem with it but they ran the loop to two breakers on the same phase. My guess is that this was unintentional since it was only one circuit and the house was relatively small.

I have run into that same thing in commercial work but the problem with it is the total overcurrent protection of those rings is the sum of the breakers so somewhere between 30 and 40 amps protecting the 14 or 12 AWG and the receptacles on the circuit.

 

[Dennis Alwon]

I have run into that same thing in commercial work but the problem with it is the total overcurrent protection of those rings is the sum of the breakers so somewhere between 30 and 40 amps protecting the 14 or 12 AWG and the receptacles on the circuit.

Correct and it never caused ab issue in a residence because you hardly ever get more than a few amps on a circuit in bedrooms or living areas. Btw, I would not use 2 breakers but I don't see an issue with one breaker.

 

[iwire]

Correct and it never caused ab issue in a residence because you hardly ever get more than a few amps on a circuit in bedrooms or living areas.

I do not understand that, its the same as installing single pole 40s on a 12 AWG, you would never do it and would point it out as a safety issue.

Now if it was two 10 amp breakers protecting a 12 AWG ring I would not see any safety issue only a code issue.

Btw, I would not use 2 breakers but I don't see an issue with one breaker.

Safety wise neither do I but it is a violation IMO and Dons proposal seems to back that opinion up.

 

[romex jockey]

Their ring circuits would basically be our #14awg made onto a 30A OCPD twice, or what we'd term double tap...

Ampacity being divisible allowed the lesser conductor(s) to be installed

Originally they'd ring a house twice , keep in mind their voltages are higher, thus magnitudes (their term for ampacity) lower

However, it's easy to see how a compromised 'ring' can cause mayhem , which given their 70 yr old debut as well as building construction is a likely bet

~RJ~

 

[SceneryDriver]

My thoughts had nothing to do with shock hazard.

25 amps is more than enough current to be a fire hazard.

But I was not saying your ideas where a fire hazard.





I never said it one run of cable would increase safety.

Your post seemed to perpetuate the myth that low voltage means safe when that is not the case.

As far as what is done in the entertainment industry .... my experiences tell me not to use that as a yard stick of NEC compliance or safety.

I misunderstood where you were going with that. I completely agree that low voltage can still cause fires due to overcurrent on conductors. Amps is amps after all. I've seen the traces on LED tape melt with a bang due to faults where no overcurrent protection was provided. The tape became the fuse. Not good. :blink:

I meant to say that from a touch perspective, a 120VAC ring circuit where an electrician is not expecting it (especially one fed from two breakers) could/would be a shock hazard even if the conductor is capable of handling the current. My response was inelegantly worded.

As for the entertainment industry, I completely agree. Lots and lots of shoddy and sometimes downright dangerous installations. I've somewhat made a career of fixing those, actually.


SceneryDriver

 

[kwired]

How 'bout dem Panthers!

Sooo... the consensus here is ring circuits are a violation (tho probably ok for LV despite it) of the NEC for parallel conductors, they are used mostly in the UK, which is a failed superpower because their breaker panels are too small, everyone still loves AFCI breakers, and receptacles should always be installed ground pin down.

Phew, tough work throwing all of that gasoline (petrol) on the fire!

kwired and SceneryDriver, I could see where a ring circuit here would throw electricians for a loop, so to speak. Even if there were no safety problems, I doubt a GFCI receptacle would work if both Line and Load side were essentially wired to line side. and I could see where mismarked cables, panels changes. or wiring failures might create a whole slew of other potential problems with a ring circuit

infinity's idea of cutting the circuit mid-point is maybe the best code compliant idea thus far.

and iwire; the driver is 300W, so it is capable of putting out 25A@12V. I know the amperage is what kills but I think I'd rather put my hand across a 12V 1000A battery than a 50A 240V range receptacle with the cover off.

If you connected line and load of a GFCI to what is essentially the same lines it will not work as intended. Depending on design you may still have voltage at the receptacle but no GFCI protection. But consider that as long as it is tripped - you have opened the "ring circuit"



Those suggesting we land each end of this circuit on separate overcurrent devices - please note I am not in favor of that practice at all for reasons you suggest it is a problem. My only support of such a circuit is if you have a single overcurrent device that is sufficient to protect the conductor size attached to it, the conductor goes out and makes a loop to all the components supplied and returns back to same point of supply. It may or may not be NEC compliant depending on how you interpret 310.10(H), but is in no way ever going to result in a potentially overloaded/overprotected conductor.

 

[Dennis Alwon]

Let's be clear I am in no way advocating hooking this up to 2 breakers. MY point earlier was that the loads in a house were small so using 2 breakers acted like one breaker in the sense of not overloading the wiring. It certainly could in another situation and I would never do this. I, in fact, have never done a loop wiring system either but, like the others I see no issue if it returned to the same breaker. I am trying to imagine what the problem would be that the cmp is worried about

 

[kwired]

Let's be clear I am in no way advocating hooking this up to 2 breakers. MY point earlier was that the loads in a house were small so using 2 breakers acted like one breaker in the sense of not overloading the wiring. It certainly could in another situation and I would never do this. I, in fact, have never done a loop wiring system either but, like the others I see no issue if it returned to the same breaker. I am trying to imagine what the problem would be that the cmp is worried about

Is the CMP worried about such a circuit?

I can't say I have used such a technique myself, but see no problem with it either. The place I may be most likely to use it is with low voltage lighting for voltage drop reasons.

 

[qcroanoke]

BTW, I dont have to worry about plagiarizing or Copy right. I can post and quote the NEC freely because the law requires its disclosure unlike BS7671 which while applicable to nearly every installation in the UK can not be posted or quoted from directly because its considered copy right in the UK. Its tragic life safety material enforced by law can not be disclosed yet you have the nerve to say we are backwards based on local amendments and that very legal disclosure.

Just like NASCAR's rulebook.

 

[Dennis Alwon]

Is the CMP worried about such a circuit?

Did you read the comment from Don's proposal... They may not be worried but they want substantiation. Not sure how to do that for them other then to say we have seen circuits done that way with no ill effect

 

[kwired]

Did you read the comment from Don's proposal... They may not be worried but they want substantiation. Not sure how to do that for them other then to say we have seen circuits done that way with no ill effect

That was so far back I already forgot about it

But I did go back and read it, and their position doesn't make any sense to me. What does their mentioned grounding electrode conductors in their response have to do with anything, this was not PI for grounding electrode conductor applications:?

 

[don_resqcapt19]

...

But I did go back and read it, and their position doesn't make any sense to me. What does their mentioned grounding electrode conductors in their response have to do with anything, this was not PI for grounding electrode conductor applications:?

That is one of the major problems with the new system used for code changes. They use the same comment for multiple PIs that they believe to be related.

 

[mbrooke]

I have run into that same thing in commercial work but the problem with it is the total overcurrent protection of those rings is the sum of the breakers so somewhere between 30 and 40 amps protecting the 14 or 12 AWG and the receptacles on the circuit.

Id argue if the ring is not broken the wire itself will be ok, but if a fault occurred on an 18 gauge cord good chance it will burn up before a breaker trips. Its the reason why countries that use rings require a bulky, impractical cord cap to contain a fuse which is essentially what our 15 and 20amp breakers do.

 

[mbrooke]

BS are basically IEC standards

NEC takes the IEC a step further (as least we've some initiative)

Their annual Earth Loop Impedance testing would be mandatory here as well, were we to install to such flimsy specifications

This is why under the NEC , where we built it right the first time, it becomes an opinion

~RJ~

That nothing :lol: Did you know? Their testing actually requires unhooking the water, gas, UFER, ground rod, ect grounding electrode conductors at the both ends and then taking an end-to-end ohm reading in order to obtain a certificate of occupancy? Guess defective wire right out of the box is norm.


Starting at 2:32 :jawdrop:


https://www.youtube.com/watch?v=zgZGbzZqTE0&list=PLcvYzDd-Xv7h-eKw9jjhyeiVRrEgNJY1n

 

[Dennis Alwon]

Id argue if the ring is not broken the wire itself will be ok, but if a fault occurred on an 18 gauge cord good chance it will burn up before a breaker trips. Its the reason why countries that use rings require a bulky, impractical cord cap to contain a fuse which is essentially what our 15 and 20amp breakers do.

How is this different from any circuit. The fact that it is a loop does not change the ability to fault. If you brake the loop then why bother having a loop circuit. Now you have two circuit or one circuit spliced in the panel. That would be what Trevor was talking about earlier. The loop is not necessary

 

[iwire]

How is this different from any circuit. The fact that it is a loop does not change the ability to fault.

Dennis, he was responding to my post with two 15 or 20 amp breakers feeding 14 or 12 AWG.

In that case the unbroken ring circuit is protected at 30 or 40 amps. That is different than one 20 amp breaker feeding two homeruns.

 

[Dennis Alwon]

Dennis, he was responding to my post with two 15 or 20 amp breakers feeding 14 or 12 AWG.

In that case the unbroken ring circuit is protected at 30 or 40 amps. That is different than on 20 amp breaker feeding two homeruns.

Yep, my bad-- I should have read the quote