GFCI for venders

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thanks growler

thanks growler

growler said:
Once the ditch work is finished running the PVC conduit is not only easy it is cheap. So why worry about getting everything in one conduit. Run a second conduit and maybe even a spare for future use.
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Thats a great idea, then I wound not have to loop every conductor through every outlet box
 
Thanks brother

Thanks brother

brother said:
in a 120/240 single phase system, a 3 wire multiwire branch circuit (2 hots 1 shared neutral) the neutral is not counted as ccc for the purpose of derating conductors. ;)
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I believe you but it doesnt seem right , if only one hot is being used on the circuit the neutral carries full load . I guess since the other hot is not being used at same time it is fair to not count the neutrals.
 
brother

brother

brother said:
This was only for the branch circuits. not the main service or feeders.
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And I agree, if you see a 240 volt breaker in my box , there is a 240 volt appliance or sub panel on the other end. Not a circuit where some one saved a few pennies using a 3 conductors instead of 4
 
acrwc10 said:
Why would you do that? Don't you know how to do electrical work correctly? :grin:
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They are suggesting 3 multi wire and one regular branch circuit in the same box, do you realize how easy it would be for some one to add a load and get on the wrong neutral ? Fried neutral :roll:
 
jetlag said:
brother said:
in a 120/240 single phase system, a 3 wire multiwire branch circuit (2 hots 1 shared neutral) the neutral is not counted as ccc for the purpose of derating conductors.
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I believe you but it doesnt seem right , if only one hot is being used on the circuit the neutral carries full load . I guess since the other hot is not being used at same time it is fair to not count the neutrals.
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If both are loaded to 20A, then the neutral is carrying 0A on a 120/240V circuit.

jetlag said:
And I agree, if you see a 240 volt breaker in my box, there is a 240 volt appliance or sub panel on the other end. Not a circuit where some one saved a few pennies using a 3 conductors instead of 4.
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Hey, it's your work, but you're dumping a lot more material in it for no good reason, IMO. I think you're comfortable with what you're familiar with, the forum is a good place to hear about techniques you might not employ now, but might help you in the long run.

jetlag said:
They are suggesting 3 multi wire and one regular branch circuit in the same box, do you realize how easy it would be for some one to add a load and get on the wrong neutral ? Fried neutral :roll:
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Then use handle ties and single pole breakers, if you think someone is going to get confused.

I am not responsible for what idiots do to my installation after I leave. If someone cannot grasp the implications of the multiwire branch circuit, which has been used successfully since Edison, then they have no business messing with it. Every commercial installation involving EMT that I have ever seen (installed prior to 2008) consisted of a mass of multiwire circuits. They are still legal, we just have to simultaneously disconnect all of the poles now. As time goes by, and people get sick of pulling dedicated neutrals for every circuit, I imagine handle ties in new installations are going to be commonplace.

Do you realize how easy it would be for someone to open the neutral on a regular circuit and get the soup knocked out of them? How do you protect that idiot? Why would you want to?

My 2?.
 
ActionDave said:
LOL. It seems to be the way the world is heading. Not only do we have the MWBC- phobes to deal with but now our own code is working against us hold outs as well.
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I wonder whats next?:confused:

All ungrounded conductors run in the same conduit or box's will have to be simultaneously disconnected?:cool:

P.S. Don't spread this around, or it will be in the 2014:mad:
 
jetlag said:
And I agree, if you see a 240 volt breaker in my box , there is a 240 volt appliance or sub panel on the other end. Not a circuit where some one saved a few pennies using a 3 conductors instead of 4
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But the installation done your way is a code violation due to derating requirements, do it as George described and it is code compliant.

MWBCs also reduce voltage drop so take a minute to realize it is not just about saving a conductor.
 
George Stolz said:
If both are loaded to 20A, then the neutral is carrying 0A on a 120/240V circuit.


Hey, it's your work, but you're dumping a lot more material in it for no good reason, IMO. I think you're comfortable with what you're familiar with, the forum is a good place to hear about techniques you might not employ now, but might help you in the long run.


Then use handle ties and single pole breakers, if you think someone is going to get confused.

I am not responsible for what idiots do to my installation after I leave. If someone cannot grasp the implications of the multiwire branch circuit, which has been used successfully since Edison, then they have no business messing with it. Every commercial installation involving EMT that I have ever seen (installed prior to 2008) consisted of a mass of multiwire circuits. They are still legal, we just have to simultaneously disconnect all of the poles now. As time goes by, and people get sick of pulling dedicated neutrals for every circuit, I imagine handle ties in new installations are going to be commonplace.

Do you realize how easy it would be for someone to open the neutral on a regular circuit and get the soup knocked out of them? How do you protect that idiot? Why would you want to?

My 2?.
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It's mostly residential where I don't like the MWBC . On commercial most likely professionals will be working behind you . And saving a conductor on every circuit can add up, on residential around here the 12/3 cost as much as 2 12/2. This is a light commercial but it is a flea market and trailer park thing that is owned and maintained by "all green" .. There will be no MWBC's installed ;)
 
hurk27 said:
I wonder whats next?:confused:

All ungrounded conductors run in the same conduit or box's will have to be simultaneously disconnected?:cool:

P.S. Don't spread this around, or it will be in the 2014:mad:
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lets keep that under raps:grin:
 
iwire said:
But the installation done your way is a code violation due to derating requirements, do it as George described and it is code compliant.

MWBCs also reduce voltage drop so take a minute to realize it is not just about saving a conductor.
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I would rather run 2 conduits to take care of the derate , the second conduit will only go half way , about 30 ft .
 
George Stolz said:
If both are loaded to 20A, then the neutral is carrying 0A on a 120/240V circuit.


Hey, it's your work, but you're dumping a lot more material in it for no good reason, IMO. I think you're comfortable with what you're familiar with, the forum is a good place to hear about techniques you might not employ now, but might help you in the long run.


Then use handle ties and single pole breakers, if you think someone is going to get confused.

I am not responsible for what idiots do to my installation after I leave. If someone cannot grasp the implications of the multiwire branch circuit, which has been used successfully since Edison, then they have no business messing with it. Every commercial installation involving EMT that I have ever seen (installed prior to 2008) consisted of a mass of multiwire circuits. They are still legal, we just have to simultaneously disconnect all of the poles now. As time goes by, and people get sick of pulling dedicated neutrals for every circuit, I imagine handle ties in new installations are going to be commonplace.

Do you realize how easy it would be for someone to open the neutral on a regular circuit and get the soup knocked out of them? How do you protect that idiot? Why would you want to?

My 2?.
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Edison was all DC current , a MWBC would have fried the negative . Westinghouse was first to use AC current. :roll:
 
jetlag said:
Edison was all DC current , a MWBC would have fried the negative . Westinghouse was first to use AC current. :roll:
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While Edison did push all out for DC, later on he did accept the AC principles, and theory's, and also took credit for many of them, Westinghouse also did not develop AC, he was just a financier who backed Nicoli Tesla with the development of the Niagara Falls Hydro generation station, and a few other things, but also ran away with many of Tesla's ideas and patients, leaving Tesla broke and and disenchanted, most likely because Tesla was not an American, and treated very poorly among the scientific community of that time.

But as far as the 3-wire Edison circuit goes, it does work in both AC and DC, Edison used it as a circuit to try to compete with Tesla and Westinghouse, in the big race to transmit power longer distance, we know Tesla won, Westinghouse took credit.


For a DC version of a multi-wire (Edison) circuit place two D cell flash light battery's together positive of battery 1 to negative of battery 2, place 3 conductors at each point: negative of battery 1, between the connection of the two battery's, and at the positive of battery 2.

so we have 3 connections for a load, N__C__P place a lamp of rated voltage between C and N and C and P and if both lights are equal in wattage there will be no current in the C wire to the battery's just like in a AC multi-wire circuit. DC polarized loads would just have to be wired to there respective poles, load 1 would have the - to N and + to C, load 2 would have the - to C and + to P, with the same result if the current of each load is equal.
 
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jetlag said:
I would rather run 2 conduits to take care of the derate , the second conduit will only go half way , about 30 ft .
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That is up to you, but there is no reason to fear MWBCs and many reasons to use them.

The circuit to an electric dryer is a MWBC.
 
Thanks hurk

Thanks hurk

hurk27 said:
While Edison did push all out for DC, later on he did accept the AC principles, and theory's, and also took credit for many of them, Westinghouse also did not develop AC, he was just a financier who backed Nicoli Tesla with the development of the Niagara Falls Hydro generation station, and a few other things, but also ran away with many of Tesla's ideas and patients, leaving Tesla broke and and disenchanted, most likely because Tesla was not an American, and treated very poorly among the scientific community of that time.

But as far as the 3-wire Edison circuit goes, it does work in both AC and DC, Edison used it as a circuit to try to compete with Tesla and Westinghouse, in the big race to transmit power longer distance, we know Tesla won, Westinghouse took credit.


For a DC version of a multi-wire (Edison) circuit place two D cell flash light battery's together positive of battery 1 to negative of battery 2, place 3 conductors at each point: negative of battery 1, between the connection of the two battery's, and at the positive of battery 2.

so we have 3 connections for a load, N__C__P place a lamp of rated voltage between C and N and C and P and if both lights are equal in wattage there will be no current in the C wire to the battery's just like in a AC multi-wire circuit. DC polarized loads would just have to be wired to there respective poles, load 1 would have the - to N and + to C, load 2 would have the - to C and + to P, with the same result if the current of each load is equal.
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Thanks for details on Edison , Tesla, and Westinghouse, my memory is not what it used to be . I was picturing a DC MWBC incorrectly. I was thinking of the batteries in parallel not series , with a pos from each battery connected to a seperate lamp and a single conductor returning the current to both battery neg . My Idea didnt represent a transformer with a center tap .
 
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