240 20 amp socket
- Thread starter Chucktin
- Start date
Dustball
Well-known member
What you received is a 30 amp twist lock receptacle. Just curious- what size circuit breaker was installed for this circuit?
Well duh!
So I shut off the breakers (double) and pulled the receptacle to find that they used an industrial grade stranded wire, 4 conductors - Black, Red, White and Green. I checked with a non-contact probe and both Black and Red were hot. What I expected. But with that receptacle installed the circuit tester kept showing the White, should be Neutral, was also hot at the screw. WTF?
After I shut off the breakers and disconnected the receptacle the White was not hot. As I expected it to be. The Black and Red were hot, and the Green was a ground as it should be (I could see other greens spliced on in the box).
Maybe I was fooled by something but I did check the probe on other 110/120 receptacles and the breaker panel and it glowed red for hot, green for safe every time.
So I shut off the breakers (double) and pulled the receptacle to find that they used an industrial grade stranded wire, 4 conductors - Black, Red, White and Green. I checked with a non-contact probe and both Black and Red were hot. What I expected. But with that receptacle installed the circuit tester kept showing the White, should be Neutral, was also hot at the screw. WTF?
After I shut off the breakers and disconnected the receptacle the White was not hot. As I expected it to be. The Black and Red were hot, and the Green was a ground as it should be (I could see other greens spliced on in the box).
Maybe I was fooled by something but I did check the probe on other 110/120 receptacles and the breaker panel and it glowed red for hot, green for safe every time.
Did you check the white with a meter or just a non contact voltage tester?
Obviously nobody took the time to communicate what kind of receptacle you actually wanted, you or the electrician. There are about 3-4 different kinds of 240v 20A receptacles. You could have told them you wanted a 6-20R or showed them the end on your table saw. The electrician should have asked also since you weren't specific.
Obviously nobody took the time to communicate what kind of receptacle you actually wanted, you or the electrician. There are about 3-4 different kinds of 240v 20A receptacles. You could have told them you wanted a 6-20R or showed them the end on your table saw. The electrician should have asked also since you weren't specific.
rlitman
Well-known member
No, but you can't trust a non-contact probe for that purpose. Measure the actual voltage across everything.
You also can't trust a DMM if your wire runs are very long, their input impedance is usually several megohms so they don't load down what you're testing - I've measured up to about 90 VAC (using a DMM) on wires that were abandoned (neither end connected to ANYTHING) but not removed; but when I loaded them down using a Wiggie the voltage dropped to ZERO.
Inductance isn't ALWAYS your friend, and it pays to have (and understand) more than one test device... Steve
Inductance isn't ALWAYS your friend, and it pays to have (and understand) more than one test device... Steve
sberry
Banned
So,,, now what?
wyliesdiesels
Well-known member
If you asked for a 240v 20a and he put in a 120/240 30a TL on a 15a breaker, why did you not call him back to fix it?
Didn't want him to fix it rather DIY and learn something new and three were other concerns.
As to which receptacle I was needing, 1) the saw and it's motor were right there and 2) I was promised more than once that I'd have the correct receptacle when done. Wiring a 24x36 barn took over a week. The single circuit for the saw was the only "odd" request. Everything else was lights, switches, and plugs.
My concern with the White/Neutral being hot is me wondering if that 30 Amp receptacle is supposed to read that way or is there an internal short
As to which receptacle I was needing, 1) the saw and it's motor were right there and 2) I was promised more than once that I'd have the correct receptacle when done. Wiring a 24x36 barn took over a week. The single circuit for the saw was the only "odd" request. Everything else was lights, switches, and plugs.
My concern with the White/Neutral being hot is me wondering if that 30 Amp receptacle is supposed to read that way or is there an internal short
sberry
Banned
A short would trip the breaker, should anyway.
Since you want fix his mistake.....you will need to end up with:
6-20R recept (based upon your pic in post 2)
2 Pole 20A cb in panel
#12 wire (minimum size) between cb and recept
Neutral wire-nutted in the outlet box
why not swap the cord end on the saw or wire up an adapter? it's easy to build-a-bear that caps off a wire inside, not so easy to make a neutral out of nothing.
My Garage heater has a 14-30P appliance cord on it. neutral is capped off inside. welder is the same way but 14-50P. figure it'll make "electric car ready" for the next owner super easy. for me, It makes the outlet more versatile.
My Garage heater has a 14-30P appliance cord on it. neutral is capped off inside. welder is the same way but 14-50P. figure it'll make "electric car ready" for the next owner super easy. for me, It makes the outlet more versatile.
PhysicsDude
Well-known member
If it were me, I would change the ends on my 240v tools to all be L14-30R twist locks. They're a superior receptacle design.
wyliesdiesels
Well-known member
If the saw came with a 6-20p from the factory i would not change it. Theres a reason the manu put that on.
sberry
Banned
Agree.
alfredeneuman
Well-known member
^^^^^^This^^^^^
Call the electrician back to change the receptacle and breaker.
It should be free of charge because he agreed to install the receptacle for the saw.
Call the electrician back to change the receptacle and breaker.
It should be free of charge because he agreed to install the receptacle for the saw.
sberry
Banned
I say do it, get it done. Good place to learn a little.
wyliesdiesels
Well-known member
The neutral may not be hot. You couldve been seeing induced or ghost voltage.
Try testing with a solenoid tester such as a wiggy.
rlitman
Well-known member
The resistance of the neutral back to ground should be low enough that a DMM should be reading under a couple of volts no matter the circumstances between neutral and ground. Anything more than that, and perhaps there is a problem with the grounding system (unless you have something like an old light switch or dimmer that doesn't use a neutral).
Yeah, a wiggy is less likely to give false positives to a untrained eye, but a DMM can be just fine too. However, a non-contact probe will give false positives all the time, and this is a great example of the most common type.
I see what you got, I see what you were hoping/paid for. The electrician really needs to replace the breaker and the outlet for free. There might be oversized wire that he will just leave in the wall for free.
What size breaker/wire did you get feeding what you got. Can you show us a picture of your panel pointing to the breaker that you feel is the disconnect for the outlet you had installed?
If they ran the circuit properly(waiting on pictures), I would just leave it. I personally don’t like cutting off manufactured plug-ends... but you can buy dog bone adapters.
DIY, replace the breaker to a 20 amp double, the plug outlet to a 6-20 or L6-20. This retrofit will cost you between $40-$60 (depending on the outlet).
What size breaker/wire did you get feeding what you got. Can you show us a picture of your panel pointing to the breaker that you feel is the disconnect for the outlet you had installed?
If they ran the circuit properly(waiting on pictures), I would just leave it. I personally don’t like cutting off manufactured plug-ends... but you can buy dog bone adapters.
DIY, replace the breaker to a 20 amp double, the plug outlet to a 6-20 or L6-20. This retrofit will cost you between $40-$60 (depending on the outlet).
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sberry
Banned
I got to wonder sometimes, the op said he was gonna have the right recept, the one he wanted and didnt, how would the working pro's feel about this,,, well,,,, some guys on the net said You should stop what you are doing and come back and change this for free. Bet we would hear about that.
mike93lx
ALLIANCE MEMBER
Why is everyone assuming the electrician made a mistake? The op said he "expected" a different plug. If it wasn't specified, I'd say the electrician went above and beyond to run a 4 wire circuit
OP requested a 20A recept, received 30A. That's not the same.
3w vs. 4w - agreed not spec'd.
locking vs. non-locking - agreed not spec'd.
If a 30A recept is on a 15a cb, that's quite less than going beyond.
OP still needs to confirm cb and installed wire size to determine correction possibilities.
I can see why this install didn’t end well...
I clicked on this thread to see what the hell a 240 20 amp “socket” was...figured I may learn something about something I never heard of...oh well.
OP may want to hand the electrician the saw plug...and state...I want something to plug this into!
I clicked on this thread to see what the hell a 240 20 amp “socket” was...figured I may learn something about something I never heard of...oh well.
OP may want to hand the electrician the saw plug...and state...I want something to plug this into!
I can see why this install didn’t end well...
I clicked on this thread to see what the hell a 240 20 amp “socket” was...figured I may learn something about something I never heard of...oh well.
OP may want to hand the electrician the saw plug...and state...I want something to plug this into!
Are you saying sockets, plugs, plug-ins, outlets and receptacles aren’t all the same?
Are you saying sockets, plugs, plug-ins, outlets and receptacles aren’t all the same?
Yes, yes I are
Last I learnt...sockets are what you screw a bulb into or use on your ratchet wrench.
That..and I wanted to see how big that 20 amp bulb is...that thing has got to be huge. Either that...or how you screw that bulb into that thar outlet...
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Thanks for all the comments. To be as clear as possible I told them I wanted a 220/20 amp receptacle to piwe a table saw. I guess he was thinking a of what I'd call a "cabinet" saw. When I saw the receptacle I said wait that's too heavy all b neexis this. The electrican said he didn't have one in his truck but would be back with one. This king to save him some extra effort I volunteered to go down town and get the correct receptacle. He said that wasn't necessary. As things worked out I was not in a hurry to to finish the shop portion, we wanted the barn lights and switches completed first and the company needed him on another job for a week. 10 days, 2 weeks, later he came back to finish the job. By then we were up to our ears with hanging the walls and ceilings. Rather than cause them, the company, any other pain we signed off on the job as completed.
wyliesdiesels
Well-known member
You signed off on the job as being completed when it wasnt? Whoops!!
Did he forget to swap out the receptacle? Dunno. Figured I could cope with the swap.
Guess I wasn't clear enough.
My concerns -
why was I seeing the tester telling me there was current on the Neutral/White when I wasn't expecting any.
And
Should I install the "correct" (230/29amp) receptacle on that stranded cabling or swap the plug to fit the receptacle.
I was hoping (silly me ([emoji2955])) that somebody would comment on what kind of a circuit that "twist-lock" receptacle was _appropriate_ for, surely not mine, and whether or NOT my solution was appropriate AND safe.
Guess I wasn't clear enough.
My concerns -
why was I seeing the tester telling me there was current on the Neutral/White when I wasn't expecting any.
And
Should I install the "correct" (230/29amp) receptacle on that stranded cabling or swap the plug to fit the receptacle.
I was hoping (silly me ([emoji2955])) that somebody would comment on what kind of a circuit that "twist-lock" receptacle was _appropriate_ for, surely not mine, and whether or NOT my solution was appropriate AND safe.
You have received that information within these 36 posts in several replies as well as follow-ups for you to determine what can be done to properly correct what they installed.
If you are still asking these q's after all this, you should leave this alone and call them back.
Just buy a dog bone electrical connecter.
https://www.amazon.com/dp/B06WRT9LLP/?tag=atomicindus08-20
https://www.amazon.com/dp/B06WRT9LLP/?tag=atomicindus08-20
Attachments
sberry
Banned
Buy the recept you want. Check the breaker. It and the recept need to match. It needs 12 or better for 20. The breaker needs to match the plug on the machine if its factory. No adapter in this case.
There is a place for some of them, this isn't it. There is 50 4 wire to 30 3 wire for travel trailer. There are 15 to 30. There may be there legal other guys can comment without hurting my feelins.
There are some conditions custom ends and cords are installed on machines.
But factory cord end is the max allowable breaker and in some cases the equipment may require full power of that. circuit. I believe to recept there is no exception for wire size to recepts for 30 and under. Only recept I am familiar for this is welding 50A.
Input to dedicated hard wire might not match the breaker. In theory the installer has calculated this.
There is a place for some of them, this isn't it. There is 50 4 wire to 30 3 wire for travel trailer. There are 15 to 30. There may be there legal other guys can comment without hurting my feelins.
There are some conditions custom ends and cords are installed on machines.
But factory cord end is the max allowable breaker and in some cases the equipment may require full power of that. circuit. I believe to recept there is no exception for wire size to recepts for 30 and under. Only recept I am familiar for this is welding 50A.
Input to dedicated hard wire might not match the breaker. In theory the installer has calculated this.
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theoldwizard1
Well-known member
You pull out you trusty Simpson 260 ! Or make your own test light. 25W or smaller 120V bulb. One end to the white, the other to the green. If it lights up, then there is something seriously wrong in the load center (breaker box).
(This same issue shows up in cars, which is why smart auto diagnosticians use an incandescent 12V test light or even a double filament tail light bulb instead of a DMM.)