Will GFCI protection work

[Bill Annett]

I have an outside light that is controlled by a wall switch. The conduit from the light ( still need to install ) goes to a junction box in the basement. Power is brought into that junction box. The switch is on the first floor about 10 feet away from the Junction.

The homeowner did not want to tear up any walls so the switch leg goes up to the attic, across the attic, down an opening around a soil stack and across the basement to the junction box with the power.

The run is about 170 feet. I did a voltage drop calculation for 340 feet and with the size bulbs they have it will be about 3%. Voltage drop

My question is can I GFCI protect this circuit? My concerns are that since the hot conductor goes 340 feet before it gets back to the light and the neutral goes a few feet, I felt that the GFCI protection would not work.

On my next trip, I was going to test it with a pig tail light socket at the junction box. To be honest, I have no idea if it will work.

Any input will be appreciated.

Thanks
Bill

 

[Dennis Alwon]

It should work fine.-- you could set a gfci dead front switch at the basement JB or is the entire circuit gfci. If the gfci is in the panel then you could have issues with the distance

 

[Bill Annett]

Dennis Thanks for the information. I was planning to install a GFCI receptacle in the Junction box and protect it thru the load side of the GFCI Receptacle.

 

[Little Bill]

I have an outside light that is controlled by a wall switch. The conduit from the light ( still need to install ) goes to a junction box in the basement. Power is brought into that junction box. The switch is on the first floor about 10 feet away from the Junction.

The homeowner did not want to tear up any walls so the switch leg goes up to the attic, across the attic, down an opening around a soil stack and across the basement to the junction box with the power.

The run is about 170 feet. I did a voltage drop calculation for 340 feet and with the size bulbs they have it will be about 3%. Voltage drop

My question is can I GFCI protect this circuit? My concerns are that since the hot conductor goes 340 feet before it gets back to the light and the neutral goes a few feet, I felt that the GFCI protection would not work.

On my next trip, I was going to test it with a pig tail light socket at the junction box. To be honest, I have no idea if it will work.

Any input will be appreciated.

Thanks
Bill

If it's just a light, it doesn't need GFCI protection. Is there another reason why you want to protect it with GFCI, such as an outdoor receptacle on the circuit?

 

[hurk27]

Dennis Thanks for the information. I was planning to install a GFCI receptacle in the Junction box and protect it thru the load side of the GFCI Receptacle.

If you are thinking of protection from overload or short circuit like a breaker of fuse does, then no a GFCI does not provide this kind of protection, a GFCI receptacle will pass through what ever the circuit protection device can supply, as for the the protection if someone comes into contact with the hot and Earth then the GFCI will act to provide shock hazard protection only, but there is no code that requires a lamp pose to be protected by GFCI unless it has a receptacle on it.

 

[Bill Annett]

Good Morning, My only reason to GFCi Protect that circuit it to allow the conduit to have only 12 inches of cover ( table 300.5). It is easier to dig for 12 of cover that having to dig a ditch about 19 inches in order to have 18 inches of cover. The older I get the less I like to dig.

Thanks again for all of the information

Bill