4kw 30amp

[ninfan77]

I have a 30amp dryer outlet, 10/3. Is it wise to tape off the white/neutral as I don't need it for 240v or a return of 120v at the outlet?

Secondly, Can I pigtail 10/2 or 10/3 (ignoring the neutral again) to wire up 4 - 240v outlets?

The outlets have 3 lugs, 2 hot, and 1 ground.

The other thought, would be to mount a subpanel, ground it to a cold water pipe (entire house is copper), using the existing 10/3 at the dryer outlet to come into sub panel, and then place 4 - 10amp breakers, and run 14/2 to each (4) outlet individually.

At 4x1000w I should be under the 80% load for a 30amp line as well, staggering start times just to be safer.


The other option I'm thinking:

Wire a 10/2 from 30amp breaker in service panel to a T104 Intermatic Timer. Run that to a dual 240v outlet, and pigtail one more onto that.

Wouldn't that be the easiest solution? With all 4 ballasts turning on at same time, would I run the risk of tripping the 30amp breaker? The outlets are 15amp each, would the first outlet overheat due to pigtail to the 2nd? Or should I just hardwire the ballasts directly to the timer?

 

[PharmaCan]

The question of whether to use the dryer outlet or run a new wire is a matter of proximity, ease and if you think you will want to use the dryer outlet for a dryer. If you don't need the dryer outlet, make your decision based on what would be the easiest to hook up. A wire is a wire basically, so if it is easier to use the dryer outlet, use it. If it would be easier to run a new wire, do that.

If you don't need a neutral, you can use the neutral wire from your dryer outlet for a ground. I'd switch that neutral wire in your panel over to the ground bus, just so it's obvious what's being used for what, and put some green tape on both ends of the wire. (Just barber-pole a few inches of the wire so that it's obvious it's a ground.)

You shouldn't notice any difference between pigtailing to two receptacles as opposed to hard wiring to the timer, as long as all your connections, receptacles and plugs are in good shape. You'd have to run pigtails from your power cords to the timer anyway so it's not like you'd be eliminating pigtails by hard wiring.

4,000 watts at 240 volts is about 17 amps. I really don't know what the surge would be on that, but I'm sure someone here does.

PC

 

[ninfan77]

thanks PC for your quick reply. I won't be using the dryer.

RE: the neutral wire, the 10/3 already has a green ground wire attached at the service panel. I was planning on keeping that green wire as well as the 10/3 i'm adding to extend that branch grounded at the dryer outlet. Wire nutting the red/black together and taping off the white/neutral.

I'm only going about 3 feet across the room and through a sheet of drywall (conduit used), then pigtailing that 10/3 branch off dryer outlet into 4 - 240v outlets, each with a 240v timer.

I figure it like this.

10/3 from dryer outlet - pigtail split to 2 lines, those 2 lines are then each running to 2- 240v outlets. This should eliminate the risk of a set of 2 outlets overheating from just being daisy chained straight through. Each outlet will also be grounded at the box and receptacle.Am i correct?

 

[PharmaCan]

What you are saying is not consistent with what you are saying. lol Let me ask you a couple of questions and set a couple of ground rules and then we can figure this out.

When talking about wire size, you don't count the ground, only the conductors. So 10/2 is romex with black, white and ground wire. 10/3 is romex with black, white, red and ground inside. If you don't need/want a neutral, use 10/2 - unless you just happen to have 10/3 sitting on your shelf than use it.

If abandoning the neutral, cut the exposed end of the wire off and put a yellow wire nut on the end. Taping it is mickey mouse.

How many timers do you intend to use?

PC

 

[ninfan77]

Yep using 10/3, as that's what I have available. don't need the white, nut it off at end.

The timers I found are 15amp, 240v each. I figured i'd need 4, one per 1000w light, they only have one plug on them.

Seeing as one timer is large in size, it hides the 2nd outlet on receptacle, so I figured I'd need 4 receptacles total, with a timer on each.

I assumed i couldn't daisy chain the receptacle- x - x - x -x as the amperage would add up and overheat the 1st outlet. If I'm correct, by splitting the 10/3 into 2 junction boxes, and then each junction box would have 2 seperate outlets, for a total of 4.

That would work, correct?

 

[PharmaCan]

Now I see what you are saying and what you want to do will be fine. (You could actually go to one junction box then from there to the receptacles, but going from one junction box to two junction boxes then to the receptacles isn't going to make a lot of difference as long as you use the #10 or #12 wire from the first box to the second ones.)

PC

 

[ninfan77]

And with what i'm describing, 2 junction boxes, then to the 4 receptacles... will pose no problem as each receptacle is 15A. The first one won't overheat in this scenario, that's my main concern. Thanks PC for all your help.