GFCI for venders

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jetlag

Senior Member
I have a customer wanting to use storage buildings on skids to furnish small sales places for venders to rent for the day. The buildings will be backed up agaist a fence in a straight row. I am thinking I will install a 100amp outside panel with 7 gfci breakers to supply the 7 buildings buildings with a 120v ,20 amp rec. outlet. The buildings will use a cord and plug . The code says I can install 15 #12 thnn conductors in a 3/4 " pvc . Can I run 7 hot , 7 neutral and only one #12 grounding conductor ?
The reason for the Gfci breakers is so I will only have to bury the conduit 12" , since the customer is going to dig the trench by hand
 

mcclary's electrical

Senior Member
Location
VA
I have a customer wanting to use storage buildings on skids to furnish small sales places for venders to rent for the day. The buildings will be backed up agaist a fence in a straight row. I am thinking I will install a 100amp outside panel with 7 gfci breakers to supply the 7 buildings buildings with a 120v ,20 amp rec. outlet. The buildings will use a cord and plug . The code says I can install 15 #12 thnn conductors in a 3/4 " pvc . Can I run 7 hot , 7 neutral and only one #12 grounding conductor ?
The reason for the Gfci breakers is so I will only have to bury the conduit 12" , since the customer is going to dig the trench by hand



IMO, the 12" rule (if gfi protected) is for residential only, and also, it only applies to a single 20 amp circuit, not multiple circuits in your case.
 

iwire

Moderator
Staff member
Location
Massachusetts
And with 14 current carrying conductors you will need to up size the conductors.

I would use GFCI receptacles not breakers.
 

jetlag

Senior Member
thanks mcclary

thanks mcclary

IMO, the 12" rule (if gfi protected) is for residential only, and also, it only applies to a single 20 amp circuit, not multiple circuits in your case.

Well so much for 12'' trench, I didnt go back and read the code before posting, in that case I will use GFCI rec. outlets and not the breakers. Will the one #12 EGC be enough for all 7 circuits ?
 

ericsherman37

Senior Member
Location
Oregon Coast
Well so much for 12'' trench, I didnt go back and read the code before posting, in that case I will use GFCI rec. outlets and not the breakers. Will the one #12 EGC be enough for all 7 circuits ?

Like iwire said, if you're running 14 current-carrying conductors in one conduit you'll have to derate them per 310.15(B)(2)(a) and thus probably upsize them. If you upsize the ungrounded conductors then you'd probably need to upsize the EGC as well per 250.122(B).

Kinda gettin' into a big ol' wad of wire there.
 

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
Why not install 3 multiwire branch circuits plus one regular circuit?

Assuming 120/240 single phase, of course, you'd be down to 8 CCCs and be back out from under derating. The only difference would be buying two pole breakers instead.
 

jetlag

Senior Member
Like iwire said, if you're running 14 current-carrying conductors in one conduit you'll have to derate them per 310.15(B)(2)(a) and thus probably upsize them. If you upsize the ungrounded conductors then you'd probably need to upsize the EGC as well per 250.122(B).

Kinda gettin' into a big ol' wad of wire there.

Im not sure but he might just have to promise them 1200 watt each . that way can put two recepts on each circuit and reduce to 8 current conductors and 1 EGC. I rather stay away from the multi wire branch circuits when possible.
 
Im not sure but he might just have to promise them 1200 watt each . that way can put two recepts on each circuit and reduce to 8 current conductors and 1 EGC. I rather stay away from the multi wire branch circuits when possible.

*hypnotizing* Look into my eyes, and repeat after me, Shared neutrals are evil, Shared neutrals are bad, shared neutrals are evil. No to shared neutrals!! ;)
 

jetlag

Senior Member
thanks george

thanks george

Why not install 3 multiwire branch circuits plus one regular circuit?

Assuming 120/240 single phase, of course, you'd be down to 8 CCCs and be back out from under derating. The only difference would be buying two pole breakers instead.

Explain, I am counting 11 ccc's that way
 

LEO2854

Esteemed Member
Location
Ma
*hypnotizing* Look into my eyes, and repeat after me, Shared neutrals are evil, Shared neutrals are bad, shared neutrals are evil. No to shared neutrals!! ;)

If you cut the neutral off it will not be shared:grin::grin::grin::grin:
 

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
Im not sure but he might just have to promise them 1200 watt each . that way can put two recepts on each circuit and reduce to 8 current conductors and 1 EGC. I rather stay away from the multi wire branch circuits when possible.

Why would you do that? Don't you know how to do electrical work correctly? :grin:
 

iwire

Moderator
Staff member
Location
Massachusetts
This was only for the branch circuits. not the main service or feeders.

Why?

There is no difference at all electrically.

What I am saying is why does the installation of an overcurrrent device turn the safe practice of sharing a neutral for services and feeders into an unsafe condition with branch circuits?

If a service neutral opens it effects the entire building, if a branch circuit neutral opens up it only effects that circuit.
 
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growler

Senior Member
Location
Atlanta,GA
The code says I can install 15 #12 thnn conductors in a 3/4 " pvc . Can I run 7 hot , 7 neutral and only one #12 grounding conductor ?


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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