splitting circuits and sharing neutral

[fuente]

I have a situation where I'd like to run 12/3 from the panel into the attic and splice into 2 12/2 circuits. I"m wondering what the pros advice would be on splitting circuits like this and what the opinion is on this.

My issue is that I have a limited amount of space to pull wire from the panel into the basement. If I can decrease the number of runs from say 15 12/2 (and 14/2) to say 10 total, that would help me a lot.

Of course dedicated circuits (bathroom receptacles, microwave,ect) based on NEC and others based on load (furnace, washer, dryer, etc) would not be split.

Thanks for all the help !

[Snoonyb]

Just be carefull to connect each 12/3 hots to the same buss or you have the potential of wiring 240V to a 120V appliance.

[fuente]

Just be carefull to connect each 12/3 hots to the same buss or you have the potential of wiring 240V to a 120V appliance.

you're talking red wire to red breaker buss, black wire to black breaker buss?

[Snoonyb]

you're talking red wire to red breaker buss, black wire to black breaker buss?

NO!

In the service panel there are two hot buss bars thet the individual breakers are attached too.

If you are using full sized breakers, and they are stacked verticaly in a single row, then every other breaker is on the same buss bar.

If you are using mini or twin style breakers, then both feeds are on the same buss bar.

Here is a link that should expand on the subject;

http://www.foxelectricsupply.com/content/products/ProductCatalog.asp?qshCatId=24827

[fuente]

NO!

In the service panel there are two hot buss bars thet the individual breakers are attached too.

If you are using full sized breakers, and they are stacked verticaly in a single row, then every other breaker is on the same buss bar.

If you are using mini or twin style breakers, then both feeds are on the same buss bar.

Here is a link that should expand on the subject;
http://www.foxelectricsupply.com/con...qshCatId=24827

thanks. so the red AND black are connected to the SAME hot buss bar? My electrician is doing the new panel install (upgrade), and as this is my first house and it has a fused panel, well, I've never seen a panel with breakers before.

I'm sure my electrician will give me a tutorial also. Thanks for the info.

[kactuskid]

These circuits you're proposing to install are called multiwire branch circuits and they can be very dangerous in that there is a 240 volt potential in the junction box. There are quite a few requirments to installing them to make them safe. The neutral wire should be pigtailed to the device to insure it never becomes open and you should use a double pole breaker in the panel that has the handles tied. This insures that both legs are opened at the same time. I would never advise this type of circuit to be installed in a panel using fuses. Besides the safety issue of not being able to disingage both legs simutaeniously your fuse panel is too small to handle this type of additional load you want to add to it.

Here's a link that'll explain about them
http://www.inspect-ny.com/electric/multiwir.htm

[fuente]

sorry for the confusion. This install will NOT be on the current fused panel. I"m getting a new 200A breaker panel installed. That is where these circuits will be installed.

[fuente]

when you say the neutral should be pigtailed to the device, I am unclear on this.

If I'm bringing the 12/3 into the same duplex receptacle, it's easy enough to pigtail it. I am unclear why that would be an issue though (I don't have the knowledge and am looking for some).

But what about if I run the 12/3 to a j-box and then split it into two circuits; i.e. red to black on circuit 1, black to black on circuit 2...can't I just wire nut the three neutrals together? And at the device, would I still need to pigtail the neutral? I guess I'm unclear.

I'm sure someone can set me straight. Thanks.

[Snoonyb]

thanks. so the red AND black are connected to the SAME hot buss bar?

If you are using mini twins (WITHOUT THE TIE BAR) you connect the red and black to the individual connection screws on the breaker.

If you you are using full size breakers, (IT IS CRITICLE THAT YOU UNDERSTAND THE DIFFERENCE), you can only connect one of the colored conductors to one screw on this style breaker, then the other to the next breaker.

If you connect both conductors to the terminals of this style breaker, whether there is a tie bar or not, you will guarantee to have 240V in the "J" box.

when you say the neutral should be pigtailed to the device, I am unclear on this.

There are couple of methods of wiring recep.
1) When you are wiring a series of recep. you will have a hot pair and in the same box will also be a "traveler" which connects to the next downline box.
Its an acceptable practice to wire to the side screws effectively using the device as a conductor.
2) Another method, often used in commercial installation and you'll see why,
Is to twist the colored conductors, with a pigtail and wirenut and then attach to the hot side of the receptacle, then repeat the method with the white/neutral.

Should the device fail, this method allows you to replace it and leave the downline receptacles hot and what is connected to them still operational, such as a computer or an alarm system.

There is a simple method of determining the correct receptacle wiring;
With the recep. in your hand, the face, facing you and with the ground stake down. The set of screws/plug-ins on the right, are the hot side.

If I'm bringing the 12/3 into the same duplex receptacle, it's easy enough to pigtail it. I am unclear why that would be an issue though (I don't have the knowledge and am looking for some).

If you are wiring two hots to the same recep, there is a tab which connects the screws together, cut and separate, connect the white to neutral and you will have two separate 120V circuits which can be individually controlled at the breaker.{Use a 20AMP commercial recep.}

But what about if I run the 12/3 to a j-box and then split it into two circuits; i.e. red to black on circuit 1, black to black on circuit 2...can't I just wire nut the three neutrals together?.

YES

And at the device, would I still need to pigtail the neutral? I guess I'm unclear.

NO


I'm sure someone can set me straight. Thanks.[/QUOTE]

[fuente]

got it. Pigtailing the neutral when using the receptacle as the conductor makes sense. FWIW, it this code or just good practice (it's obviously good practice). I also understand about the tabs and how to use them.

Thanks for the help. I'm sure when I actually see the breaker panel it will make better sense as well.

[Snoonyb]

Have the elec. show you each.
Also, talk with them about running a 3/4" flex with a pull leed to a "J" box in a couple of locations rather than individual 12/3's.

[fuente]

Have the elec. show you each.
Also, talk with them about running a 3/4" flex with a pull leed to a "J" box in a couple of locations rather than individual 12/3's.

yep and yep. Thanks.

[Snoonyb]

Have your electrcian show you several different styles of breakers, and while your at it, talk to them about installing a 3/4" flex to a "J" box in a couple of location.

Instead of useing multiple 12/3.

[fuente]

Have your electrcian show you several different styles of breakers, and while your at it, talk to them about installing a 3/4" flex to a "J" box in a couple of location.

Instead of useing multiple 12/3.

yep and yep...again

[HayZee518]

As long as you're running circuits maybe you should consider running a sub panel up to the attic. That way the home runs won't be so long from the new circuits. If you're restricted to the amount of wires in a wall space then it just makes sense to run a sub-panel, that way you'll only have one cable in the wall space down to your main panel.