pulling 120v off 240v circuit, safely? temporarily.

[vintagespeed1956]

hi guys, first time posting in this part of the forum. i DID sirch but didn't find what i was after... i'll keep it short.

so yesterday i pulled a new circuit to my garage for my weldin'. i installed a 30amp dual pole breaker in the box, ran 10/3 romex to a Jbox and some 10/3 flex down to my 4" outlet box and ran the Red & Black to the outlet along with Green ground to complete the 240v outlet.

now here's where it gets sketchy.. i figured i could pull 120v off this circuit and install a couple outlets to power my other smaller welder and small air compressor, currently they put a strain on my 15amp circuits in the garage. none of them will be on simultaneously and i wont be pulling anywhere near 30amp capacity ever.

i installed a separate 4" box with 2 separate duplex plugs, and connected Red to the brass screw on one 20amp duplex, Black to brass screw on the other duplex, Green to grounds and i ran the White neutrals together to the neutral in the 10/3.

now my questions (i know you probably are already throwing stuff at your monitors!);

1. is this safe as a "temporary" installation until i can run a sub panel in the garage?

2. when i plugged in my cheapo 120v plug tester it says my hot/neutral are reversed, they're not. why?

3. is there any configuration where i can utilize these 120v plugs until i run the sub panel?

i feel like my yesterday's project was only 50% successful at this point. the breaker is off and i'm awaiting your flaming.

it was over 120 degrees up there in the attic yesterday and i had to swim through 2 feet of blown-in just to pull this circuit and i feel like a real dumb dumb for not just pulling some 6/3 for a sub panel instead of wasting time with this. and i'm not ready to get back up there until it cools off this fall.

thanks for the help, sorry it was longer than i thought.

 

[Mustang51js]

You will be ok as a temp,what size wire did you run for 20 amp outlets,if #10 then you won't have any issues for wire,but could overload the outlet,which I doubt will happen. Can't figure out why it says reverse without a picture,could be a loose neutral or not spliced all together. Or they are actually reversed lol

 

[theoldwizard1]

If your long term plan is to put a panel in the garage, buy the size panel you want now. Ignore the size of the main breaker. The 10/3 is protected by the upstream 30A breaker.

To do it your way, you would have to have a NEAM 14-30 receptacle. Then a 14-30 plug and cord going to a pendant box where you can have both 120V and 240V receptacles. This will cost you twice as much.

 

[vintagespeed1956]

You will be ok as a temp,what size wire did you run for 20 amp outlets...Can't figure out why it says reverse without a picture..

it's all 10ga, the hot/neutral aren't reversed. i figured this was maybe because of the shared neutral between the outlets and dual pole breaker? edit: or maybe it's because my tester is only a cheapy 120v outlet tester and can't understand this circuit? i dunno. hell, maybe i did wire them backwards, i was probably heat stroked around that time. i'll double check.

i'm gonna go home and take some pics and probe around with my meter...

If your long term plan is to put a panel in the garage, buy the size panel you want now. Ignore the size of the main breaker. The 10/3 is protected by the upstream 30A breaker...

i'm afraid i'm not smart enough to understand everything you stated, sorry. after the summer i'll be willing to climb up there and tackle pulling 6ga for the sub panel, to power the welder circuit and some outlets. i'll probably put the whole garage on the sub panel at that point.

for now if it's unsafe to use the 120v outlets, i'll just do away with them and use the 240v. i just didn't like what my tester was telling me and i dont want to burn 'er down.

 

[Aceman]

Replace the breaker with a 2 pole 20 and replace the duplexes with GFCI receptacles.

 

[aandpdan]

It's against Code.

The duplex receptacles, a NEMA 5-15 or 5-20, can not be used on a circuit protected by a breaker of more than 20 amps. It doesn't matter the wire size you are using.

Table 210.21(B)(2)

 

[vintagespeed1956]

gotcha, okay well i found the problem. also removed the duplex 120v plugs from the circuit as advised, i'm just running the 240v outlet for now.

when i got home i busted out the MM and started probing, i found 125v on the neutral. so i started digging. all connections in the panel were good so it was time to get dirty and get back up into the attic where the Jbox is located.

the 10/3 romex that i ran into the Jbox from my panel was shorted at the knockout clamp. i over tightened it like an idiot and pinched it enough to short through the jacket. bad move... i redid the connections and really padded up the jacket where it enters the box clamp and didn't crank it down like an idiot. re-tested the 240v plug with the MM and everything checked out proper, 125v on each leg and 245v combined. (edit: and NO volts on my neutral which is now capped and unused.)

plugged in the TIG and boogered up some 3/16" 6061 at 175amps. all is well.

thanks you guys for helping me out and spurring me in the right direction, this was a dangerous situation and with your help, at least i was smart enough not to just ignore the problem and burn down the house. jeez, i can't believe i effed up something so simple. i will be MUCH more careful with those clamps in the future.

beers all around! thank you!

 

[Vegaman_Dan]

I've been wanting to add a 120v lamp to the 220v circuit I have for my air compressor to be a simple power on indicator. I turn it on and off with the breaker switch, but sometimes I'll forget about it and then when the air pressure finally drops enough around 2 AM, the compressor kicks on in the night's silence. Having that visible light over the compressor would be a good reminder for me. For my needs, I think I can just pull off a hot and neutral for a local light.

 

[wyliesdiesels]

I've been wanting to add a 120v lamp to the 220v circuit I have for my air compressor to be a simple power on indicator. I turn it on and off with the breaker switch, but sometimes I'll forget about it and then when the air pressure finally drops enough around 2 AM, the compressor kicks on in the night's silence. Having that visible light over the compressor would be a good reminder for me. For my needs, I think I can just pull off a hot and neutral for a local light.

U need a neutral. Does the circuit have a neutral? If not, then u would have to pull one, if in conduit, or run new Nm...

 

[alfredeneuman]

I've been wanting to add a 120v lamp to the 220v circuit I have for my air compressor to be a simple power on indicator. I turn it on and off with the breaker switch, but sometimes I'll forget about it and then when the air pressure finally drops enough around 2 AM, the compressor kicks on in the night's silence. Having that visible light over the compressor would be a good reminder for me. For my needs, I think I can just pull off a hot and neutral for a local light.

A whole thread on this exact subject is here:
http://www.garagejournal.com/forum/showthread.php?t=296498

 

[Vegaman_Dan]

A whole thread on this exact subject is here:
http://www.garagejournal.com/forum/showthread.php?t=296498

Wow. Three pages of nobody able to agree upon a simple solution. I'm not terribly surprised really. There are some options at least. None simple or clean for a solution, but there are some options.

 

[Orionrising]

Could just replace the j box your flex comes our of with a 6 or 12 slot sub panel for like $25

 

[ripperd]

I've been wanting to add a 120v lamp to the 220v circuit I have for my air compressor to be a simple power on indicator. I turn it on and off with the breaker switch, but sometimes I'll forget about it and then when the air pressure finally drops enough around 2 AM, the compressor kicks on in the night's silence. Having that visible light over the compressor would be a good reminder for me. For my needs, I think I can just pull off a hot and neutral for a local light.

Or if you don't have neutral available, wire up 2 120v lights in series across the 240v. Must be the same wattage.

 

[sberry]

What got past in the other thread was that simply adding wire to an existing circuit may not be legal without other fuses. Put a ball valve on, shut it off, or let the comp come on at 2 or turn it off, fix a leak but one of these days we are going to see a thread about devices to protect from the added safety devices.
The incident we see in the other thread was from something added to the original design.

 

[wyliesdiesels]

What got past in the other thread was that simply adding wire to an existing circuit may not be legal without other fuses. Put a ball valve on, shut it off, or let the comp come on at 2 or turn it off, fix a leak but one of these days we are going to see a thread about devices to protect from the added safety devices.
The incident we see in the other thread was from something added to the original design.

Actually whats not legal is adding a separate conductor to a circuit wired with NM...