[Steve Burke]

Please advise on the correct way to connect a lighting circuit to a dryer circuit.

We have a small (10x10) outbuildng where the previous owner ran 10-3 (red, black, white, ground) through a 1" rigid non metallic conduit to a small building (10x10') that is a short distance (<10') from the main house. The circuit is used for a dryer. We would like to have a small light in the area and do not want to pull another circuit from the house (while 1" conduit used, the routine is circuitous and pulling more will be a pain).

Is it possible to use one leg (red or black) of the 30A ciruiit to create a lighting circuit?

Thank you.

 

[jbfan]

NO. You need to install a 4 circuit sub panel, then feed the dryer and the light from the panel.

 

[Jim Port]

The circuit should be dedicated to the dryer so IMO adding a subpanel would not be an option if the current setup is used. You could not run a new circuit to the outbuilding as the code prohibits multiple circuits going to outbuildings. You would need a feeder and a panel.

Your idea is incorrect because general purpose circuits for lighting and receptacles are prohibited from being greater than 20 amps.

 

[Steve Burke]

Hmmmm...Two opposing opinions. How do i decide if, and how, to use an existing 30amp service to provide both power (for a dryer circuit) as well as a lighting circut?

 

[bob22]

I dont' think they are opposing.
WOuldn't this building would need to be treated like a detached garage circuit fed by a subpanel and with its own ground rod, neutrals isolated from ground in subpanel?

 

[rjniles]

While it is not to code and I am sure I will be chastised for suggesting it but for a small load like a light:

I would install a small plug fuse holder (with a 15 amp plug fuse) in a 2 gang electrical box immediately next to the 30 amp dryer receptacle. Wire with a piece of 10-2 (a hot, neutral and ground) from the dryer receptacle to the new box. Connect the hot side to the fuse holder, wire the other side of the fuse holder to a switch in the same box. Wire from the switch to the light.

 

[secutanudu]

I dont' think they are opposing.
WOuldn't this building would need to be treated like a detached garage circuit fed by a subpanel and with its own ground rod, neutrals isolated from ground in subpanel?

If he installs a subpanel, yes.

A subpanel, in my opinion, is the only viable option, and even that is questionable because of what Jim said. But I'd do that before doing what rjniles suggested.

Then again, if it were me, I'd run a new 60- or 100-amp service to the building, put a subpanel in (isolated neutrals) and drive ground rods.