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View Full Version : Wiring new circuits , junction box sizes.


bobbuilder123
Dec 12, 2007, 07:36 AM
Hi All,
I need some help guidance for a home project.
I am installing all new 4 lights and 2 outlets. I have pulled a 12/2 romex (2+ground MAIN ROMEX) from the main panel. I using "star" topology versus "daisy-chaining) as circuits are spread out in different locations. By using star topology one draw back is There are too many Junctions that needs to be made to the MAIN ROMEX. As each device will have its own pair of wires running from the MAIN ROMEX.
Question:
1. Is there a junction box available that is laid out like a panel? What I mean is a junction box that will have "metal" bars with lugs where I can connect individual out going circuits from the MAIN ROMEX. This will help me avoid making twisting joints to MAIN ROMEX for each of the individual light/outlets.
2. I thought about buying a mini panel from the local store and modifying it (by not using the breaker but permantly shorting the what would be a Circuit Breaker, NOTE that the MAIN ROMEX has 15A breaker at the MAIN PANEL.).
Q: Is using mini-panel as mentioned in (2.) a violation of electrical code?
3. Other suggestion are also welcome and appreciated.
I am a new member and for last few days I have been going through some of the Q/A that I was interested in. I was really impressed by members knowledge and generousity in sharing it with other members. Keep up the good work. Thanks in advance.:)

tkrussell
Dec 12, 2007, 02:57 PM
Question:
1. Is there a junction box available that is laid out like a panel? What I mean is a junction box that will have "metal" bars with lugs where i can connect individual out going circuits from the MAIN ROMEX. This will help me avoid making twisting joints to MAIN ROMEX for each of the individual light/outlets.


No, only special order are these available, or make your own with DIN terminal strips. This is very costly, time consuming, and prone for loose connections if not done perfectly.

Using Star is not very practical , only done when necessary, Daisy chain is much more popular, and easier to manage.

How many of each set do you have? There are large wirenuts, and even larger split bolt connectors that need two layers of tape available to make up splices.

Splices are much better for this purpose.




2. I thought about buying a mini panel from the local store and modifying it (by not using the breaker but permantly shorting the what would be a Circuit Breaker, NOTE that the MAIN ROMEX has 15A breaker at the MAIN PANEL.).

Sorry, I don't fully understand this method, but the word "shorting " scares me, so I say no . Sounds too Disney. Material must be used as listed by UL, and no modifying allowed.

How many cables, and we can spec and size a method.

Washington1
Dec 12, 2007, 08:33 PM
1. Is there a junction box available that is laid out like a panel? What I mean is a junction box that will have "metal" bars with lugs where I can connect individual out going circuits from the MAIN ROMEX. This will help me avoid making twisting joints to MAIN ROMEX for each of the individual light/outlets. Waste of time, and money. I'm with TK, daisy it! You are not running low voltage Cat5E or the like.



2. I thought about buying a mini panel from the local store and modifying it (by not using the breaker but permantly shorting the what would be a Circuit Breaker, NOTE that the MAIN ROMEX has 15A breaker at the MAIN PANEL.).
Q: Is using mini-panel as mentioned in (2.) a violation of electrical code? Yes! Again, I'm with TK.

bobbuilder123
Dec 13, 2007, 09:27 AM
Hi,
First, thank u TK and Washington for your suggestions.

No, only special order are these available, or make your own with DIN terminal strips. This is very costly, time consuming, and prone for loose connections if not done perfectly.



Where can I find this special order places.


Using Star is not very practical , only done when necessary, Daisy chain is much more popular, and easier to manage.


I am having a office and a bathroom put in an attached 2 car garage (which is insulated just as like any other room in house, that is, ceiling, wall etc are finished with insulation inside and covered with sheetrock and painted. The 2 car garage has only one car entry door so other half is just open empty space that I am trying to utulize.)
The panel is inside the house at the far end of the garage near the garage door.
I need 4 lights, 2 GFCI and 1 Light/Exhaust Fan combo. All of them except GFCI has a separate switch.
I have pulled a 12/2 romex for GFCI that is only for Whirlpool/bath tub.
The I have also pulled another 12/2 romex to take care of all the other lighting/FAN and GFCI receptacle. From this 12/2 ROMEX (ROMEX2) I need 4 lights, 1 light/fan combo and 1 gfci connected. The problem is that all are spread out in 4 different corner of the garage.
I thought the easiest thing to do will be to pull ROMEX2 in a BIG juction box and spilt the circuit in star configuration. This is because all light and GFCI are spread out in four different corner of garage and all switches are approximately in same location near where the ROMEX2 junction box is.



How many of each set do you have? There are large wirenuts, and even larger split bolt connectors that need two layers of tape available to make up splices.
Splices are much better for this purpose.

A I have mentioned above 4 lights,1 light/Exhaust Fan combo and 1 gfci.






Sorry, I don't fully understand this method, but the word "shorting " scares me, so I say no . Sounds too Disney. Material must be used as listed by UL, and no modifying allowed.
How many cables, and we can spec and size a method.

Let me explain myself better, as I understand it:
1. A sub panel already has Ground and Neutral bars/terminal strip built in.
2. then there 2 metal planes across which the circuit breaker sits. Then MAIN HOT is connected to the one of the planes of metal plane of the panel. The function of the circuit breaker is to connect/disconnect the HOT PLANE to the wire that is attached to the breaker.
3. I attach a Terminal strip/bar with that can be purchased at BIG BOX to the plane that has power. This means to the HOT PLANE.
4. I pull my ROMEX 2 into the subpanel as MAIN. Connect ground to ground bar, neutral to neutral and Hot to hot plane (where I have attached the terminal strip/bar, I can use a screw to attach or use solder).
5. Effectively, what I have now is a MINI MAIN POWER subpanel with MAXIMUM current capacity of 12/2, 20A. Instead of the usual 100A,150A,200A etc.
6. From this sub panel I run individual wire for each light/swith combo. Now I don't have to use any splicing etc. at the sub panel/junction box, I can attach them to connection strip with screws.
7. My question is does this violate any codes. Will it pass inspection.
My reason for using star configuration is that for daisy chaining I will have to drill through many beams in the ceiling and perhaps open up the ceiling sheetrock. I am not comfortable doing it. With Star configuration I am able to run most of the wire parallel to the joist and hence easier to pull wire and less messing with sheetrock.
Once again I am extremely grateful to both you for having taken time to answer my question. Thank you in advance. :)

Stratmando
Dec 13, 2007, 02:56 PM
If I am reading correctly, you want to connect hot to "Hot Plane"?
I think you mean to one of the main busses. You need to go through a breaker.
Star is fine. You could have 2 junction boxes with Extension Rings(4" X 4", has no back, and doubles the volume of box. Make all connections tight.
I would consider Small 60 Amp panel I garage, myself.
I think most Electricians prefer Daisey as you have less connections under wirenuts, And you don't have to go in to attic for repair, all can be done in room. Do the Star if chosen with exact and good connections. Do it right once and forget it.

bobbuilder123
Dec 13, 2007, 05:21 PM
If I am reading correctly, you want to connect hot to "Hot Plane"?
I think you mean to one of the main busses. You need to go through a breaker.

I do not know how to upload the image in this discussion, so I will try explaining again.
1. I want to use a sub panel as a junction box.
2. The MAIN/LINE power coming into the Sub Panel will be the 12/2 Romex that I have pulled from the house's 200A Main panel.This 12/2 Romex already has a 20A circuit breaker in the main 200A panel.
-I will connect the ground/copper wire of the 12/2 romex to GND bus of the sub panel
-Connect Neutral to the Neutral bus/bar of the sub panel.
- Hot/black wire of 12/2 romex to power plane as usually done.
The circuit breaker usually sits across two isolated planes (two shiny metal islands, probably tinned copper). What I want to do is attach/solder a bus bar (with screw on terminals that u can purchase at home depot or Lowe's etc.) to the plane where the 12/2 romex's hot/black wire is connected. I can the use the screw on terminals on this bus bar to connect hot/black wire going to the lights/switches/receptacle etc. I can use the Ground and Neutral bus bar's screw on terminals for connecting white/neutral and the ground/copper wires going to the lights/switches etc. All I am trying to do is avoid twisting many wires together with the twist caps.
I hope I have explained it better than before. Thanks in advance.

Stratmando
Dec 13, 2007, 06:44 PM
Get a 8" X 8" X 8" junction box, drill enough holes for all and connect. The panel/Buss deal is not worth the trouble, or what you will end up with.
Also, the GFI, if it had conductors going to junction had 2 sets. Power could go down to GFI. Back up to to junction, and protect 3? Other outlets in Garage.
Drilling of the buss and method described, makes my head hurt.
Good Luck, Best of Christmas and the Holidays.
Is there a problem with 60 Amp sub panel in Garage?

bobbuilder123
Dec 13, 2007, 06:58 PM
Hi,
Thank u all for your suggestions! I have given up my "modifying" the sub panel idea. After visiting few stores, I have managed to find a 8x8x4 box with enough holes that I can punch out. I will have to twist many wires together that's the only thing I am bit uncomfortable with,because don't know what the maximum is allowed according to code. I will visit the township and find out.



Is there a problem with 60 Amp sub panel in Garage?
Yes, I will have to drill through many joists in ceiling, The township will NOT allow any exposed cables carrying "power" in/on garage ceiling or wall. Every Hot wire has to be concealed. With junction box placed in right place I will end up running most of the cable parallel to the beams.

Thank u all and have a happy holidays.:)

tkrussell
Dec 13, 2007, 07:04 PM
Well done Strat.

Stratmando
Dec 13, 2007, 07:15 PM
You don't have to have all the whites under 1 wirenut, can have a #12 jumper and hook to a bunch of other Neutrals, another if needed. Good connections are important. Are made better with fewer wires under a wirenut. Same goes for other conductors(Hots and grounds).

bobbuilder123
Dec 13, 2007, 08:52 PM
You don't have to have all the whites under 1 wirenut, can have a #12 jumper and hook to a bunch of other Neutrals, another if needed. Good connections are important. are made better with fewer wires under a wirenut. Same goes for other conductors(Hots and grounds).
Thanks for the info. I will let you guys (and gals?) know in a week if my DIY electrical adventure passed the inspection or not. Out of many inspectors in my town, there is one who is really pain in the arse. Unfortunately, he is the one I am assigned to :( . I had a Main service upgrade done by a licenced electrician with 10+ years in the business, the inspector gave him a hell of a time, failing him three times on ridiculous things. e.g. 8 ft grounding bar he had hammered in the ground was 1/2" above the ground level. Funny thing is when I was looking for the junction box at one of the Home depot and asked a retired electrician who was working there, that I needed a box that would have 2.25 cu. inches per connector volume, he correctly guessed the town I live in and the name of the inspector :D
Thank you and once again this is a great site! Keep it up. Hopefully, I will also be able to contribute on some topic.:)

Cobraguy
Dec 14, 2007, 08:12 AM
Do you guys understand why a large JB will work and the sub panel idea won't?