We want to thank Triad Magnetics, a Friend of CircuitBread specializing in magnetics and transformers, for supporting this tutorial! Go to triadmagnetics.com to see their line of transformers that can be used anywhere in the world that can transform down from 240V to whatever you need or from whatever you're working with up to 240V. Again, we're grateful to Triad Magnetics for supporting free educational content like this!
Can I connect one 240v hot wire to only one connecting point while leaving the other connecting point empty? While connecting the neutral and ground to the neutral and ground busses? Will the double pole breaker still work for only 1 240v wire connected to only one of the two connection points on the double pole breaker, as long as the amps and watts are correct?
In Australia, unless there is NO supply connected always assume it's live and test before you have to touch a hot wire and even then short it against the neutral. When testing if using a multi meter unless you know what you are doing DON'T. I can make any multimeter read 0v (or close enough) across 120v, 240v, 415v without any issue at all, just put the meter on the DC range. Even 120v can and does kill, then there is the danger of fires if you don't know what you are doing. If you you don't have the appropriate training get someone in, this stuff is so dangerous.
Point of correction. The 240v is technically not out of phase. They are 180 degrees apart not 90 degrees. If they were out of phase you would have 208 v because you would have a three phase supply. You have the common 240v split phase service.
Questions about the breakers: 1) When a 2-pole 240 volt breaker (spanning two slots in the panel) looks like two separate breakers, is that just an artifact of the construction or is it actually two separate breakers, one per leg? 2) Does a 2-pole 240 volt breaker connect to the neutral bus or does it have exactly two connections (for the two hot lines)?
First off is that a sub panel or phony panel feeding off a main panel. If so why is the neutral grounded to the box, and is the box earth grounded? Normally you would not ground the box if its a sub or phony panel its bonded at the main. Also why are the 2 120 volt wires larger then the natural wire. Shouldn't all 3 be the same ga wire it would have to be for DC and wile ac is alternating current both wires need to be the same ga or the larger wire won't do anymore then the smaller wire can do. It always confused me why older dryer circuit lines and stove lines do not use a 4 bare copper wire for ground even thought the neutral and ground are the same its still a safty issue.
The white wire on the left attaching to the ground bus probably is a green ground wire instead of a neutral. They just did not put green tape on it. The 240 v circuit goes out the bottom. I cannot find the incoming ground wire. The incoming neutral is black instead of white. The bottom 120 v breaker is not used.
Yes, actually closer to 120v each, when measured from the L1 bus to neutral or ground and from the L2 bus to neutral or ground. L1 to L2 voltage will be 240v.
@@adansoniaconfectioneryengi3742 It's single phase center tapped. There's one coil winding and it revolves in the same direction from L1 to L2. If the rotation of the windings were reversed at the mid point it would be opposite phase or maybe 2 phase, but it's never done that way that I know of. Two hot wires, one at L1 and the other at L2 gives 240 volts for a 240 volt appliance.
question. i have 20 amp breaker but need another 20amps tu run a pool heater. have the pump and the heater on the same circuit. can i just change the existing 20amp breaker to a single pole 40 amp? and change the receptable to a gfci that feeds them for extra safety?
That sounds very dangerous, mostly because the wire is almost certainly sized for 20 amps, not 40. You'll heard it said (roughly) that "breakers protect the house, not the people inside it." A 20 amp breaker is to make sure that your wire doesn't get too hot and melt/start a fire. By putting a 40 amp breaker on it, you're removing that protection. This sort of thing is definitely best left to a licensed electrician.
power co. changed the meter ,I have 110 each leg @ 50/50amp junction box, new cable to breaker box in home, No I can't get 220 from 220 breakers ,.. WHTTT!??? please need hot water Tnx
I am only getting 124 volts on each leg of outlet and on each screw/wire of braker and when combine both legs of 124 volts on either outlet or braker I get 0 volts. Replaced braker and still 0 volts. Any idea why can't get 240 volts? I am using the left side of braker box with GE 30 amp 2 slim brakers together. Do you think I have to move braker to right side of braker box to be able to get the 240 volts needed for drier? Right side is full with 3 double 240 volts brakers, how to add 1 more? Please advise.
If we connect two hot wires to get 240 volt than how we get the return. Usually, in 240 volt supply we connect only one hot wire and a neutral for the return
why doesnt this situation require a neutral conductor -- with two hots that are 180deg out of phase? is red behaving like neutral when black is hot, and 1/2 AC cycle later they reverse?
Basically, yes. Neutral is the return leg of a standard system. But with the two sides being out of phase, they both act as a "neutral" in that one is acting as a return leg for half of the cycle. Though this is not technically a neutral, you can still have a separate neutral even in this case, making it easier to pull 120V out of the supply down the line.
the left and right neutral bars are bonded to each other but there is a separate ground conductor connected to the ground bars, and I’m not seeing any obvious bonding between the neutral and ground bars.
Yeah, I should have mentioned that! In romex, particularly, the ground wire is bare. And for our grounding to earth with the shed, house, and solar panels, it is just a bare wire in each case.
If those two 120v lines are positives then how the heck do you get usable power? In school we learned that you need + and - not two +-es!? Someone please enlighten me!
It's because they're out of phase. So, in AC circuits, the polarity is constantly switching between positive and negative. With the two 120V lines, when one is positive, the other is negative. Because of that, there's a 240V difference between the lines at their peaks. I hope that helps!
@@CircuitBread I'm no expert but I have it on good authority that each 120v leg in the US is in phase, not out of phase. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-nOSYHUxHxG8.htmlsi=9ZKqKAihgHpHSoCF
Yep! I guess I should've been more clear. I have five 240V circuits in my house but that's a lot less than the 120V circuits I have. Perhaps "less frequent than the 120V circuits"? Or something like that?
@@CircuitBread Yeah definitely less common. Many houses don't even have them, and the ones that do only have one or two compared to the dozens of 120v outlets. I guess it depends on what you mean by "not common".
So, if I need a 3 prong outlet for 240v, would I need some device to convert it or how would I get a 3 prong outlet to be 240v? I am trying to convert a server rack to 240v they only have 3 prongs. (They do support 240v)
You don't actually need three prongs for 240V. In the US, for 120V, you have ground, neutral, and line. Ground is the round one in the bottom, neutral is the larger slit, and line is the smaller slit. Wiring for 240V, you simply make the neutral another line which is out of phase with the other, making the 240V different. If you look at an older 240V dryer plug, you'll note that it's only three plugs and it's basically this configuration (but the plug is bigger because it's setup for 30 or 40 amps, not 15-20 amps.) Newer dryer plugs are 4 plugs because they have the two lines, a neutral, and ground. But if your server is setup with a 3-prong plug and expecting 240V, it's fine to do it without a neutral line.
@@CircuitBread thanks a ton for the informative response. would it be safe for neutral and ground to be combined or we just forgo neutral all together?
When you buy the receptacle, it should come with instructions on exactly how to wire it. If the wires are appropriately color-coded, it's pretty straightforward.
My 240v outlet plug/receptacle for generator has 2 hots, a neutral and a ground. Does or can the ground/green wire and white neutral go into the same ground buss bar at the main panel? Thanks!
Hey Michael, they are usually kept separate and they really should be kept separate. The neutral line is connected back to the grid and is part of that circuit, whereas your ground buss should be literally connected to a bar that is driven into the ground or some sort of ufer. As always, when in doubt, get an electrician to help or do it for you. I hope this clarifies things!
@@bills6946I am only getting 124 volts on each leg of outlet and on each screw/wire of braker and when combine both legs of 124 volts on either outlet or braker I get 0 volts. Replaced braker and still 0 volts. Any idea why can't get 240 volts? I installed on left side of braker panel because right was full with 3 240 volt brakers. Do I need to move new braker to the right side to get the 240 volts? Please advise. Please advise.
You'll need to check modern building codes for a true legal answer but my recommendation is definitely not. You'd be using the ground as the neutral, meaning that your bare wire *could* be energized (not all loads use the neutral wire) and you'd be left without that protective ground. OR you'd be wiring it without the neutral (which would be fine for many 240V loads) so that you have your ground wire but certain loads wouldn't work. Again, I can't provide legal advice or anything like that, but I personally wouldn't do it. But I don't mess around with electricity, I always err on the cautious side.
this is completely legal if you reclassify the neutral as a line by using red or black phase tape or heat shrink (NOT SHARPIE) on both sides it is an extremely common configuration, virtually every water heater and air conditioner is wired this way
remember: any fully "240" /250v appliance will never use a neutral, ovens and clothes dryers are 4 wire because they require 125v for the lightbulbs, controls and even fan motors in some cases
@@ethernet01I am only getting 124 volts on each leg of outlet and on each screw/wire of braker and when combine both legs of 124 volts on either outlet or braker I get 0 volts. Replaced braker and still 0 volts. Any idea why can't get 240 volts? Outlet for drier has 4 prungs, ground, neutral and 2 of 124 volts. Do I need to move the double slim braker to the right side of braker box which is full with 3 x 240v brakers? Please advise. Please advise.
@@rolandtheron833 becareful he is leaving a LOT out its not worth your life you are risk doing this on your own as the utility wires going into your meter to your panel are always live unless you have the city turn it off for you. unless there is a disconnect between the meter and panel i would think. dont just rely on youtubers for stuff like this its illegal to do on your own... and you need to know a lot about bonding and code
So I have 4 wires red, black, white, green going from my box to a box is my shed. Red and black connected to the breaker like you have here. White goes to that neutral in both boxes. Green also goes to the neutral in both boxes. I guess that green really doesn’t need to be there as a second neutral. A buddy who has a lot of experience with 240 and works on 240 in a plant said that is pretty common and the green is hooked to the neutral if there is no ground to earth. Is this right?
Yep! But for larger RVs that have 50 amp plugs, they are technically 240V plugs. And maybe 30 amp plugs? I'm not sure about that. However, (and there may be exceptions to this but from my limited experience) the trailer takes the two legs that are out-of-phase and just uses them independently as 120V sources, separating them at the internal panel, much like a normal panel box in a house.
Did you solve your issue? I got the same problem: I am only getting 124 volts on each leg of outlet and on each screw/wire of braker and when combine both legs of 124 volts on either outlet or braker I get 0 volts. Replaced braker and still 0 volts. Any idea why can't get 240 volts? Please advise.
Great job. The warning about touching came too late, as we were making faces every time your fingers were touching those things we are taught to never ever touch. Great easy energy and explanation of a complex process. Your vocal volume was way better than most too. Keep them coming!
😂 thanks for the feedback! Yes, I should have mentioned that earlier. I had a very bad experience getting shocked as a child (I've thought about doing a video and showing the scars but it was traumatic and, even 30+ years later, is a bit emotional for me) so I *never* work on live panels and I'm extremely cautious doing any electrical work over 5V. It was only when I was in college and learning about voltage and current that I got to where my fear of electricity became semi-rational.
That's a good question - is it considered single phase split in the electrician industry? To me, they're 180 degrees out of phase, so I'd say there are two phases. Compared to 3 phase power where they're all 120 degrees out of phase. But I could be looking at it from a different frame of reference.
It's single phase because there's one coil and the windings go in the same direction from L1 to L2. Opposite phase would mean that the windings would reverse direction at the mid point and that's not the case. Each end is at opposite polarity from the other, so there's no such thing as "out of phase" in residential electrical wiring. It's a common misnomer. It would be more accurate to say "opposite Line" or "opposite polarity".
Well, as a retired Electrical Design Engineer, I must say, this video may be embarrassing! You said that this is in your shed. If it is, where is the Required disconnect? No main breaker as the required disconnecting means. Got one outside? There is no GEC in the panel. Where is your required Grounding Electrode and conductor connected? “This is a 2 pole breaker, that’s what I think it’s called”. Very embarrassing comment.
