# 110 and 220 in same conduit?



## puttster (Apr 30, 2012)

Right now I have a 110 plastic conduit running under the driveway to charge the gate opener battery. The plug-in electric car we are getting has the plug on that same side of the driveway, so I will have to run the 220 over to that side. 

Question: Should there be an issue with pulling the 220 through the existing conduit?

puttster


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## MikeFL (Nov 14, 2016)

The rule on different voltages in the same raceway (conduit) requires the insulation of all conductors to be equal to or greater than the highest voltage present.

You'll be fine. There's not anything on the market for line voltage with insulation lesser than 300V.


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## DexterII (Jul 14, 2010)

You need to know the size of the conduit, the size of the existing conductors, and the size of the new conductors, to ensure that you do not overfill the conduit. Also, you will want to know the depth of the conduit to ensure that it is deep enough.


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## joed (Mar 13, 2005)

You will only need one ground wire. It needs to be sized to the largest circuit using it. The existing wire may be too small for the new circuit and may need to be upgraded.


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## darren (Nov 25, 2005)

Yes you can pull 240V into a pipe with a 120V circuit. Remember a 240V load is two 120V circuits.


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## puttster (Apr 30, 2012)

The Tesla calls for a nema 14-50 outlet. Our house is new so assuming the wire in conduit now has a ground wire, can I use that ground for the 220, thus saving me one wire? 

I'm thinking I need to skinny up the new cable to pull it through the conduit even though I have no idea yet how I will be able to do it.


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## MrElectricianTV (Nov 13, 2014)

puttster said:


> Right now I have a 110 plastic conduit running under the driveway to charge the gate opener battery. The plug-in electric car we are getting has the plug on that same side of the driveway, so I will have to run the 220 over to that side.
> 
> Question: Should there be an issue with pulling the 220 through the existing conduit?
> 
> puttster


The wires for the electric car will be much larger than the circuit for a battery charger. Electric car charging circuits can be 40 - 100 amps at 240 volts.

You can use a smaller circuit on some models however your charging time will be much longer.

What size is the existing conduit?


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## joed (Mar 13, 2005)

14-50 plug needs a 50 amp circuit. The ground will need to be #8. If your existing ground is #8 then you can keep it. If it is not then you need to pull it out and replace it with #8. Use the old ground to pull in the new wires.


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## Jim Port (Sep 21, 2007)

puttster said:


> I'm thinking I need to skinny up the new cable to pull it through the conduit even though I have no idea yet how I will be able to do it.


How do you ,plan to make a cable smaller? :vs_worry:


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## Oso954 (Jun 23, 2012)

The probability of pulling a 50 amp circuit thru the same conduit is some where between slim and none.

Until the OP supplies the requested info on the conduit size and the wires or cable that are existing, he might as well be thinking about installing a new conduit.


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## puttster (Apr 30, 2012)

The circumference of the conduit under the driveway is 3 3/8." 

I do believe by now it would be slim to none pulling an additional cable with one still in there. This conduit has some 90 deg. Would it be better to pull existing back out and then pull two cables through at the same time, or would that still be too tight? What about using existing to pull a nice flexible multi wire cable through, one that will serve both outlets? Would that be easier?

My concern about pulling the existing cable out is I couldn't get one back through there, even one skinny enough just to operate the gate.


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## csab_ (Aug 16, 2011)

You probably measured outside diameter, and it's in fact a 3 inch conduit. In any case, that is plenty large for your new circuit, and it would be a pretty easy pull. I never tried to pull a new wire into a conduit with a wire already in it, but if you pull out your old wires, and then pull the whole bundle in, it should be easy.

Don't mess with cables. Just use wires. Some cables are not even allowed in conduit, and the pull is definitely harder.


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## sestivers (Aug 10, 2007)

Is the charging connection on one side of the car, is that what you mean in your first post? What if you backed in to your driveway instead of pulling in headfirst, would that put the connection on the side you need, and remove your need to route the 220V cable to the other side of the driveway?


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## puttster (Apr 30, 2012)

For a reason not clear to me, the driver cannot back into the driveway, can only back out.

Good idea using wires! I love this place. So under the crawl space on the house about 75 feet from the breakers I have my two cable ends, a 220 with 4 wires and a 110 with three wires. In a weatherproof electrical box, connect these to seven individual wires, pull those through the conduit ten feet to the other side where the conduit Tees. One Tee sends three wires up into the gate box. The other T runs horizontally for a bit, then into a box where its 4 wires connect with a nema 14-50 outlet.

That really sounds doable!


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## puttster (Apr 30, 2012)

csab_ said:


> You probably measured outside diameter, and it's in fact a 3 inch conduit. In any case, that is plenty large for your new circuit, and it would be a pretty easy pull. I never tried to pull a new wire into a conduit with a wire already in it, but if you pull out your old wires, and then pull the whole bundle in, it should be easy.
> 
> Don't mess with cables. Just use wires. Some cables are not even allowed in conduit, and the pull is definitely harder.



Sorry I just saw you thought my measurement was diameter, it was circumference. Can I still easily get the required wires through?


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## csab_ (Aug 16, 2011)

OK, so then it's probably a 1 inch conduit. You are almost certainly still fine. What is the size of the existing wire? Even if it's #8, you would have 3 #6 wires and 3 #8 wires, which is still only about 30% fill. You are good below 40%. But do check your existing wire size.


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## Oso954 (Jun 23, 2012)

Sounds like 3/4 to me.

1.050 (od of 3/4) times 3.14 is 3.297.


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## csab_ (Aug 16, 2011)

Oso954 said:


> Sounds like 3/4 to me.
> 
> 1.050 (od of 3/4) times 3.14 is 3.297.


I bet you are right.

We are getting close to having a problem here. But if OP uses #10 ground and the existing is #12 or #14, I think he/she is still OK.

Enough of speculation. We need conduit size and type and the gauge of the existing wires.


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## puttster (Apr 30, 2012)

csab_ said:


> I bet you are right.
> 
> We are getting close to having a problem here. But if OP uses #10 ground and the existing is #12 or #14, I think he/she is still OK.
> 
> Enough of speculation. We need conduit size and type and the gauge of the existing wires.


There is not much more information I can provide. The circumference of the conduit under the driveway and into the Liftmaster LA400 gate control box is 3 3/8", it is made of gray plastic and has two 90 degree elbows. I don't know the gauge of the wires in the conduit now but they are used for keeping two 7ah 12v batteries charged. Since I will be pulling those wires to pull now ones, I could easily replace them with something more appropriate to the job, or maybe even move the transformer and run a DC through the conduit.

What I am hearing is my plan to power both the gate and the nema 14-50 should be to pull six or seven individual wires through (not sure what gauges).


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## Oso954 (Jun 23, 2012)

Assuming that the existing wires and the new wires are both THHN/THWN, the fill calc comes out OK, if your conduit is 3/4 schedule 40.

If it is schedule 80, you need a 1 inch to meet the fill.

If a cable (eg UF) was used in the existing conduit, you would also need either a larger conduit, or you would need to repull the existing circuit.

Things are so tight on the fill, you need to ID what you have or get someone that can. Otherwise plan on a new conduit.


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## AH64ID (Feb 27, 2017)

It sounds like you have 3/4" conduit, and to keep what you have and run the NEMA 14-50 will take 5 current carrying conductors and a common ground. 

With 5 current carrying conductors you will need to derate the wire going thru the conduit so the NEMA 14-50 will need 3 6 Ga wires (R/B/W) and a 10 Ga ground. IF the PVC you have is sch 40 AND your other 2 wires are 14 Ga it will work as it's wired now

If you either have SCH 80 OR larger than 14 ga wires are needed then it's a no go without a sub panel.

If you have sch 80 you don't even have room for 3-6's and 1-10 for the NEMA 14-50 circuit. 

You need to measure the wall thickness of the PVC conduit and find out the wire size needed for your other circuit. 

So I'd go measure your wall thickness and see where you are at, or uncover it (if possible) and see what's written on the side. Sch 80 will have a .15" (~5/32) wall thickness and Sch 40 will have .11" (~7/64) 

DC thru the conduit will take more room, so stick with AC. 

What size breaker is the current charger on?



joed said:


> 14-50 plug needs a 50 amp circuit. The ground will need to be #8. If your existing ground is #8 then you can keep it. If it is not then you need to pull it out and replace it with #8. Use the old ground to pull in the new wires.


Per Table 250.122 he only needs a 10 ga ground for 50A service. 10 ga is acceptable for up to 60A, and 8 ga is for up to 100A service.


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## Hurst (Feb 28, 2017)

You said the gate runs off of a 24v battery? What about eliminating the power to the battery and having a 24v solar panel to charge the battery. I'm not sure if that would work with your setup, but it could eliminate the need for the additional wires and save you a little money.


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## puttster (Apr 30, 2012)

Thank you: three 6 ga, two 14 ga and one 10 ga ground if the conduit is schedule 40 (and only two 90 deg elbows?). For the 14-50, would if be acceptable to run 6 gauge under the house and then switch to 8 ga for the pull through the conduit to the receptacle?

Alos, thanks for the idea about a solar panel. Might be a good way out if I get stuck.


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## AH64ID (Feb 27, 2017)

puttster said:


> Thank you: three 6 ga, two 14 ga and one 10 ga ground if the conduit is schedule 40 (and only two 90 deg elbows?). For the 14-50, would if be acceptable to run 6 gauge under the house and then switch to 8 ga for the pull through the conduit to the receptacle?
> 
> Alos, thanks for the idea about a solar panel. Might be a good way out if I get stuck.


You need to stick with 6 ga the whole way.

Another option is just the 3 6ga and 10 ga ground and put a 50A sub panel at the fence and then have a 50A breaker for the NEMA 14-50 and a 10A breaker for the fence charger. 

But if you have SCH 40 it's just cheaper to run what you said above, and stick with 6 ga.


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## csab_ (Aug 16, 2011)

puttster said:


> For the 14-50, would if be acceptable to run 6 gauge under the house and then switch to 8 ga for the pull through the conduit to the receptacle?


The point that was made earlier: if you have more than 3 current carrying conductors in the conduit, then you need #6 for 50 amps in the conduit. No way around it.


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## puttster (Apr 30, 2012)

Thanks, all. Some good info here.
Putts


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