wiring up board

[Guest guest]

I'm thinking of wiring up my board using the multi-wire method. I'm using part of a 12/3 extension cord. White is my neutral, black and green are my hots. The only other neutral is going to be the neutral jumper on the board to get neutral to the other side of board. The hots are going to a double pole 240 breaker. (not sure what you call it). This is temporary installation for this year. It is not at all going to be permanent and may not even be used next year. I just want to know if I'm overlooking anything before fire-in-the-hole.

[Guest guest]

jeff wrote:

I'm wiring up my board using the multi-wire method. I'm using part of a 12/3 extension cord. White is my neutral, black and green are my hots. The only other neutral is going to be the neutral jumper on the board to get neutral to the other side of board. The hots are going to a double pole 240 breaker. (not sure what you call it). This is temporary installation for this year. It is not at all going to be permanent and may not even be used next year. I just want to know if I'm overlooking anything before fire-in-the-hole.

WHAT !! I know christmas wiring is temporary but the National Electric Code was written for a reason. There's no way I would wire anything, especially a circuit board, without a ground. Either use 2 cords or go to a 12/4 and use that ground. Personally, I ran 2 neutrals. Using the multi-wire method, if the neutral opens for some oddball reason you just put 220 volts across your board and lights. Puffff! All right, I feel better now. It's just the electrician in me talking.

Joe

[Guest guest]

This could give new meaning to the phrase, "smoke test.":D

[Guest guest]

Joe Lotz wrote:

There's no way I would wire anything, especially a circuit board, without a ground.




Where does ground go? When wiring to an outlet its obvious. But where or how do you ground the board?

Not sure how the board will get 240 if neutral is somehow lost. Questions, questons, questons. Well anyway I haven't powered it up yet.
Obviously I am missing something so please, enlighten me.

[Guest guest]

Jeff, the board is grounded by mounting it to the metal box. Some boards also have a grounding terminal. The grounding wire (green) from the service panel is attached to the metal box. The grounding wire is also attached to the grounding strip in your service panel. That completes an effective ground.

The grounded wire or neutral (normally white or gray) runs from the grounded terminal strip in your panel to the grounded terminals (- or white).

On a multi-wire branch circuit (1 grounded wire with multiple hot wires) the potential difference is 120 volts between the grounded and the hot (ungrounded). It is 240 volts between the hots. When the neutral is opened the only path for a load is between the 2 hot wires or 240 volts.

Multi-wire branch circuits are not that uncommon but when I have that much invested in something I lean towards the conservative for a couple extra bucks.

Hope that clears it up
Joe

[Guest guest]

Joe Lotz wrote:

Jeff, the board is grounded by mounting it to the metal box. Some boards also have a grounding terminal. The grounding wire (green) from the service panel is attached to the metal box. The grounding wire is also attached to the grounding strip in your service panel. That completes an effective ground.

The grounded wire or neutral (normally white or gray) runs from the grounded terminal strip in your panel to the grounded terminals (- or white).

On a multi-wire branch circuit (1 grounded wire with multiple hot wires) the potential difference is 120 volts between the grounded and the hot (ungrounded). It is 240 volts between the hots. When the neutral is opened the only path for a load is between the 2 hot wires or 240 volts.

Multi-wire branch circuits are not that uncommon but when I have that much invested in something I lean towards the conservative for a couple extra bucks.

Hope that clears it up
Joe

Without starting a HUGE war I would like to ask 2 questions about this reply

1. what if you are using PVC enclosures????? you wouldn't attach the ground to the enclosure????

2. what is the difference if the neutral opens up on a 4 conductor (2 hots, 1 neutral, 1 ground) and if it opens up with no ground attached to your enclosure????? the same thing will happen as far as introducing 220 volts to your board.

The reason I disagree with your statement is because if you are relying on your ground to carry your load if the neutral opens then this is against the National Electric Code.

Article 100 (definitions) of the National Electrical Code state as follows

Grounding Conductor, Equipment.

The conductor used to connect the NON-CURRENT CARRYING metal parts of equipment.

All the ground wire is going to do is protect against electrocution by directing the electricity to the earth instead of energizing the enclosure.

I will TOTALLY agree that if you are using metal enclosures that they should be grounded along with any other metal items that are not designed to be electrically energized I just don't understand your argument about if the neutral opens what purpose is the ground going to serve????? I am an electrician and I have seen 100's of times where a neutral will open in a circuit and the ground will play no part in the problem.


Once again not trying to start any wars with anyone just don't understand your argument on if a neutral opens up how a ground is going to save you from introducing 220 volts to your board???????

[Guest guest]

Mike, I'm with ya. I was trying to get Jeff a little more on track. He was running his 2 hots with the black and GREEN. I'm sure you'll agree it's worth while carrying an equipment grounding conductor as far as possible. If using a PVC enclosure there's still a metal mounting somewhere. (the heat sink or screws mounting the board) And all the grounds from the cords can be tied together which effectively grounds those cords at the cord caps. (like we never mess with lights in the rain)

Yes, there's no difference with neutral opening using the 4 conductor but at least he'd be using the green as a grounding conductor instead of the hot. That's what I was shooting for.

I think we're talking the same language.

Joe

[Guest guest]

I agree 110% with your statement ground everything possible!!!!!!!!

[Guest guest]

If you wind up having problems with Missing events. IE: channels
not turning off, it will be because this setup has 2 different phases
going to the same controller (off the double pole breaker) .
I had my controllers plugged into 2 different phases and had all kinds of problems
with missed events. You may find that after all is said and done, you will wind
up either using the internal jumpers and using 1 cord, or installing 2 cords and
making sure they wind up on the same phase at the breaker panel.

Please be carefull don't overload the netural leg.

I would urge you to spend the money and get 2 extension cords and not
put power on the ground(green) wire. (just in case somebody else happens
to mess with your wiring)

Good Luck with your display, it can be alot of fun.

Tim

[Guest guest]

Hello Jeff,

I hardwired my controllers. Attached is a pic of them. It has the grounds, neutrals and hots all hooked to GFCIs. And as Tim mentioned, make sure they are on the same leg. My fades had blinks before and after them because I had the controller wires on 2 different legs.

Hope this helps,

Tom




Edited: Spelling


Attached files

[Guest guest]

Thanks everyone for the technical advice. I do understand that grounding is a must even if I don't have a complete understanding of it. But being that there was no ground lugs on the board or in my fiberglass enclosure (which by the way has no backpan. The box was given to me couple years ago.) I thought I could make use of the funky green wire as one of my hots. I have also read posts on this forum about people just tieing there green grounds out of the way since they are not used. Also, maybe its easy to forgo grounding since our device (christmas lights) don't have a grounding conductor. Just a thought. jeff

[Guest guest]

santas helper,

Do you have gfci receptacles for every channel for a total of 64? And are these receptacles located near the panel? Then after that you run extension cords to your lights. The feed wires on the left side of your box come straight from your breaker panel, right?


I have two gfi protected circuits in my garage and every time it rains the gfis trip. Because of that I get little uncomfortable about installing gfis everywhere. But I also realize that safety is #1.