240v Duplex Receptacle

DjangoNugs said:

Hey guys I need some edumacatin from one of you electro-tech savy minds. I know it's a simple one but I can't find any helpful info on these 240v duplex receptacles. There's two holes on each receptacle's terminal screw for the wires. Do both hot wires go to the bottom receptacle? Or does one hot go to the bottom receptacle and one to the top? And is the neutral/ground on the three wire circuit bonded to the service panel at the neutral or ground bar, and does it run to the neutral or ground terminal at the receptacle? Hope that explains it well enough. Thanks in advance fellow farmers.

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240volt has 2 hots and a ground or 2 hots..a ground and a neutral wire. When we wire for lights we typically only use 2 wire grounded instead of the 3 wire grounded. When 240 volts have a 2 hots a neutral and ground..the neutral is typically there to run something that needs 120 volts in the appliance such as a timer or clock or something.
The neutral wire (white) and the ground (copper or green) have bonded bus bars in the main panel..and both are attached to a copper rod that runs into the actual ground. In a sub-panel the neutral and ground bus bars are seperate..but in a main panel it won't matter if you put them into the neutral bus or ground bus as they are connected.
Now for your duplex..make sure you are under the rated amp use by 80% and don't go over..same goes for the size of wire that will be correct for the length of the run and a circuit breaker that is correct for the wire size and amps to be used.
The duplex will have a set of screws on the right and on the left..you need to wire one side with hot #1 (red wire) and the other side with hot #2 (black) it won't matter which side as they are both hot at 120v. It won't matter if you wire the top or bottom screw as they are connected to feed the same side appliance blade. If you were to cross 2 hot wires or wire them on the same side of the receptacle you will have major problems..sparks..metal welding together and a popped or burnt breaker.
Get your self a basic wiring handbook and read it cover to cover.

Perfect. Thanks Natural. Upon jorge Cervantes recommendation I got Wiring Simplified and read through it all before starting the endeavor. Rewired my garage and ran two new circuits. Pretty much done. I just wanted to make sure before wiring this last circuit with all these 240v receptacles that I wouldn't burn down all my work. The book didn't explain much about 240v loads and circuits. And there wasn't anything I could find on the internet about 240v duplex receptacles. Doesn't seem like they're used very often. Anyhoo, you explained it perfectly. Glad I have a place like this to turn in these situations. Hopefully someone else can use this info on down the line.

DjangoNugs said:

Perfect. Thanks Natural. Upon jorge Cervantes recommendation I got Wiring Simplified and read through it all before starting the endeavor. Rewired my garage and ran two new circuits. Pretty much done. I just wanted to make sure before wiring this last circuit with all these 240v receptacles that I wouldn't burn down all my work. The book didn't explain much about 240v loads and circuits. And there wasn't anything I could find on the internet about 240v duplex receptacles. Doesn't seem like they're used very often. Anyhoo, you explained it perfectly. Glad I have a place like this to turn in these situations. Hopefully someone else can use this info on down the line.

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ya 240v duplex's are very uncommon..you won't see them in a big box store. Just be sure to know the max amps it can handle just like any other receptacle. Think of them like you would a 120volt receptacle as well..but instead of one side being neutral to complete the circuit..both sides are gonna be incoming hot

Typically, you wouldnt see 220v in a duplex outlet. Carefull with that.

LI grows said:

Typically, you wouldnt see 220v in a duplex outlet. Carefull with that.

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Hydrofarm offers them too..I think they're like 15 amps max

LI grows said:

Typically, you wouldnt see 220v in a duplex outlet. Carefull with that.

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ya know what bro..you do bring up a good point. I certainly wouldn't daisy chain these fuckers like our UK brethrens often do (they have a diff set up..some kind of looped d loop stuff I don't quite understand). If anything it would be direct wired..one duplex to a breaker. Or I would split bolt those wires together and pigtail everything. Of course following code for wire sizing

I don't see a problem with daisy chaining 240VAC duplex outlets.
There are eight duplexes on the circuit. The green dot indicates hospital grade.

seaslug said:

I don't see a problem with daisy chaining 240VAC duplex outlets.View attachment 578891
There are eight duplexes on the circuit. The green dot indicates hospital grade.

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what kind of amp rating are those outlets? 20amp?

Those are rated for 15A.

This is the 20A configuration:

Yeah Im not sure about that daisy chain,everything i know says dont do it with 240,like natural said i know they do it in europe but im not sure their setup and dont think its code here.
I usually run 10/2 incoming then 12/2 to each single 240 volt receptacle,I do multiple outlets and i tie them together with wirenuts or a splitbolt if there are to many.I dont use the duplex outlets but you certainly could,2 1ks are only 9 amps and the duplex are rated 15 or 20A depending which one you get so plenty of safety factor.

These are the 20ampers that i use pigtailed.
Hell you can even use 120v duplex and cord/plugs to run 240,its just the wiring configuration to your plugs and ballasts.I think the most important thing is not overloading a circuit,lots of way to skin this cat as long as you remember a safety factor,Pigtail away until you reach yours,i try to keep my load to 2/3 or so of the circuit but lots of people go 80%.

@seaslug Are you in Europe or Britain?

Never thought of that,he could be,if thats the case forget everything i said and contact someone who knows WTF there talking about,lol.
Not sure i like the looks of that yellow romex carryin that multi receptacle load in that daisy chain either way.

I should have put a disclaimer: I am not an electrician. I'm in the USA.
The yellow Romex is 12ga. The double pole breaker is 20A.
The circuit supplies LED luminaires with a max of 330W each.

right on..the thing we are considering is how much total amps will be flowing through body of each receptacle. Think, if I were running 4 1k's @ 6 amps each. The draw flowing through the first in the series will be heated by all 24 amps..far greater amps than they are designed for. In Europe or Britain where 240v is more commonplace they use some kind of method called a ring main..it balances the load amongst all receptacles.
The main point is if you choose to daisy chain 240v receptacles here in the US without the Ring Main method..you should never exceed 80% of the max amp rating for a single receptacle amongst the whole chain of receptacles. So if you're using 20 amp plugs..the entire load on the daisy chain should never exceed 16 amps total.

Now I understand; thanks Natural.

I'm convinced I'm safe and probably close to code.
http://www.bobvila.com/posts/82844-15-amp-outlets-in-a-20-amp-circuit?page=1

how many fixtures for the one circuit?

According to my math..your 15 amp circuit (15 amp plugs) can handle a total of roughly 10 fixtures. The 12 gauge wire is fine as long as the run of all wires doesn't exceed 50 feet total or you will suffer a voltage drop. Your weakest point in the whole system is the 15 amp receptacles..the wire and breaker are fine if under 5o feet total. So you must abide by the limit of your receptacles.

seaslug said:

I'm convinced I'm safe and probably close to code.
http://www.bobvila.com/posts/82844-15-amp-outlets-in-a-20-amp-circuit?page=1

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They are talking 120v circuits there,not 240,Thats common and how most all homes are wired but I still dont think its code anywhere in the US to daisy chain 240v.
Your 20a breaker matches up to your 12g wire for sure and your load is lower with the leds but i still beleive pigtailing each duplex on its own wire is safer with 240.With your daisy chain the wire in the beginning of the run ends up carrying the load for all the fixtures which i guess would be ok if you have a decent safety factor but there is a reason its not code in US im just not sure what it is,maybe @hiboy can explain it.