madpenguin
Member
That's correct.Could I run a MWBC like you explained and then have my line out off terminals 2 and 4 going to two recepticles, these would be timed, and then split the two hots as you said with one going to one recepticle and one going to the other?
Yes, that's correct as well if your talking about your always hot receptacles. However, it's better to wire nut and pass straight through than to overburden the terminals with lots of thick wire.And then have a second line out that would be wired to terminals 1 and 3, the incoming lines to the timer, that would then also go to two recepticles with the two hots split between the two recepticles as well.
Yep. That's how I'll explain it below.I guess you could do the same thing with pigtails as well.
Yep. The always hot receptacles.Pigtail both the incoming hots so that you have one pigtail from each hot going to the incoming terminals on the timer and the other one just flowing through to recepticles.
Eh... Go with the wirenut/pigtail method. Yes, if the terminals will accommodate multiple #12 solid wire safely then I suppose so, but pigtail anyway. It's about the most solid and safest way to make an electrical connection as long as you do it right.I think both ways would work safely. Am I right?
Yep. As long as you terminated the red and black conductors to a double pole breaker ( each wire originating from a separate hot buss bar). Don't get the idea of using 2 single pole breakers one on top of the other tho. You have to be able to kill both conductors with one handle throw.Basically, as far as the timer and main panel goes, the circuit would be seen as 240v. But it would be split between the recepticles and be 120v.
Hallelujah♪♪ Hallelujah♫ Hallelujah♪I think that would be safe and possible and it would also balance the loads I think. I also think that would work so that two recepticles are timed and two are constant.
They are one and the same. A 240v circuit will trip at 20A just as a 120v circuit will trip at 20A. What your doing is allocating 10A for the timed red wire and 10A for the timed black wire. Now, remember, that only leaves you with 6A for your always hot receptacles. No dehumidifier or AC unit. Should be plenty tho for fans, sump pumps and air pumps.What I don't get with a set up like this is how to determine wire size and breaker size. I guess essentially it is a 240v circuit, but the appliances would be running on 120v...so would you size everything according to the amp draw for a 240v circuit then? Or for a 120v circuit?
The breaker will essentially see a 240v load even tho everything is at 120v. Just because it appears to be a 240v circuit to the panel (if everything is exactally balanced out), that doesn't mean you can draw "double the amps". Your still working with 2 individual 120v circuits.
Yep. You've just made the last 10 pages of frustration all worth while. Finally, someone who can read!!!!!edit: I just noticed that the out going line on the timer wiring diagram is only 2 wire. I, or anyone else, would have to use three wire, like the incoming line, for the outgoing lines as well to keep the nuetral.
Yep. You got it.I believe if you wire nutted the incoming nuetral and the outgoing nuetrals together with a pigtail going to the nuetral terminal on the timer then everything would work fine.
Am I understanding all of this correctly or is my logic ass backwards? If I have this right then this will probably be my last question.
For those of you who may need a more detailed walk through, I actually wrote one before I even fully read mr-naturals78's post... I just assumed.... And wound up getting served as it were. So here it goes:
I'm going to be really basic and go step by step. I'm not trying to insult anyone, I just want to make sure everything is understood and done correctly.
Let me replace that diagram with something a little easier to look at. I can't stand it when people cross lines on wiring schematics instead of using a half circle. I've just color coded it some:
Don't let those "supposed" arrows fool you. Those are the contacts or switches that will close when the timer reaches your set point. In other words, they will "extend" to meet the posts coming from terminals #1 and #3, thereby completing the circuit and supplying power to terminals #2 and #4. Right now, the diagram is showing the timer in an "off" position.
Your clock motor runs off 120v, so it has a neutral going to it. Terminal #A should be isolated from the frame of the box. Please make sure I'm correct on this. Setting atop a black piece of plastic or something so it doesn't touch the metal frame. For that matter, all terminals should be isolated from the frame except the ground.
I'm also going to assume that the clock is pre-wired to terminals #A and #3.... Please correct me if I'm wrong on this.
To the far left where it says Line 1 and Line 2 plus the Neutral. That is your incoming 12/3.
Here is what you want to do if you want 2 timed 120v receptacles and 2 always hot 120v receptacles. As soon as your 12/3 feed enters the timer, strip it. Leave yourself about 6" or so of wire, maybe more. I don't know how big that thing is and how much room you have inside it but we'll need to do some splices. If you have too much wire, snip some off. Make sure atleat 1/4" or 3/8" of outer sheathing enters the timer. It needs to be secured with NM cable clamps or if your using conduit, then the correct fittings for that. There has to be standard knockouts on that timer to run cable or conduit through.
Cut an entire piece of 12/3 off the roll that is about 6" long. remove the outer sheathing to get the individual conductors. These will be our pigtails. Keep the bare ground as well (or use one of those green insulated grounding leads I pictured earlier). You'll need 2 separate 12/3 wires coming in the opposite side. One for the timed receptacles, and one for the always hot receptacles.
So we have the main 12/3 feeder coming in and also 2 separate 12/3's for our load out wires..... You'll need some red wire nuts.
First terminate your grounds as it's good practice. The incoming 12/3 ground, both grounds from the 12/3's and your 6" pigtail. Put all the ends together so they are even and wire nut the hell out of them till your hands hurt. If you back the wire nut completely off and they are not twisted together very well then you should manually twist them together with linemans pliers. Then put the wire nut back on. Terminate your (only) free pigtail to the grounding terminal in the timer.
Do the same exact thing with every color wire only leave one of the out-going 12/3's alone. Bend that entire stripped cable around the front side of the timer box to temporarily get it out of your way.
Wire nut the incoming 12/3 black with the other 12/3 out going black along with a black pig tail. Wire nut them very good. Terminate the black pigtail to terminal #1.
Wire nut the incoming 12/3 red with the other 12/3 out going red along with a red pig tail. Wire nut them very good. Terminate the red pigtail to terminal #3.
Wire nut the incoming 12/3 white with BOTH 12/3 out going white wires along with a white pig tail. Wire nut them very good. Your doing the same thing here that you did with the grounds. Terminate the white pigtail to terminal #A. It is IMPERATIVE that the neutrals be evenly twisted around one another for atleast 3 turns. This is a MWBC and the neutral cannot come loose.
wire nutting 4 #12's together should hurt the hell out of your hands when your done. If it doesn't, then your not twisting it long enough.
After that, you should just have a black and red conductor from one of the out going 12/3's. The one that you bent back out of the way.
Terminate the black wire to terminal #2 and terminate the red to terminal #4. This cable will feed your timed receptacles.
The other outgoing 12/3 will feed your always hot receptacles.
I think that takes care of the timer box unless I've missed something.
I think I've also described how to terminate the MWBC to 2 separate receptacles in the gang boxes as well. Just make sure you pig tail the neutrals everywhere. If your feeding a bank of 4 handy boxes all connected together, then don't daisy chain your neutral from receptacle to receptacle.
Keep both outgoing 12/3 neutrals separated in the gang boxes. The always hot cable, make 2 white pigtails to wire nut to the incoming neutral and only terminate those to the always hot receptacles.
The 12/3 cable that feeds the timed receptacles, take 2 white pigtails and wire nut them to the timed incoming neutral. One pig tail to each receptacle. 2 incoming neutrals, 2 pigtails on each. keep em' separated or you'll create a parallel return path for current with one or both banks of receptacles.
Hope I didn't loose anyone there. mr-natural78 said the same thing only in less words.
Remember, this timer is rated for 40A. Need more power? Do the same proceedure only use 10/3 on a 30A double pole breaker and use 30A rated receptacles.
If you want to try and max it out, use 8/3 on a 40A breaker along with 50A rated receptacles (they don't make 40A rated receptacles).
If you can get your hands on an ammeter (ampmeter), the clamp on type, clamp it around the neutral wire in your panel when everything is at full load. If you've evenly balanced the load between both always hot receptacles, you'll see 0 amps worth of current making it back to the panel. Well, should be under an amp anyway. MWBC's are really neat in that way and serve their purpose well.