Electrical question...

[Coytee]

We've been talking about putting a movie on in the field in front of my house. One issue is getting power down there. Not really a fan of patching two or three 100' extension cords together...

Then this idea struck me.

I have a 70' length of 6-3 w/g wire that I used to run to a second distribution panel in my garage. This is the amount that's left that will probably get used to run a 30 amp line to the garage door (might go higher but for now, it's LOW on my list)

So, here this wire sits.

My brother in law is an electrician and I put this past him today and he thought it would not only work....but might actually put less strain on the hot lines.

Take a 2-gang breaker, 30/40 amps maybe... run this wire to the box and attach black/red each to one of the breaker poles. Hook white/ground as usual.

This would give two hot leads in a single casing and run this out 70' into my yard and then attach a 250 line of 12/3 w'g to it and at the end of this line (which might not need to be that long)

Anyways, at the end of this line put 2 or 3 outlets (4 or 6 plugs total) attaching one half of the plugs to the hot black, the other half to the hot red and use the white and ground shared between the two.

This would not be for anything other than 'movie night in the field' so it's not a permanant type of thing, just something to get power fed to the field.

My brother in law said he thought it would work fine AND because of the shared neutral line, would draw less or stress less each other line. I don't really know what he said but the gist of it was, because of the shared white wire, each hot leg would be better off.

Regardless of that tidbid.... as well as temporarily putting aside the inherent dangers of cords laying on the ground outdoors....

What are your thoughts on the raw mechanics of the idea?

[jwwrs]

Coytee, Your first concern should be how much amperage you are going to require at the very end of all this.

You must know how much your max. load will be, ie...what will the total amps be with EVERYTHING you will have plugged in at the final point.

You were alright until you threw the 250' of 12/3-w/g into the mix( I think). Sorry, just had a hard time following the garage door thing, and wheather or not you were adding breakers to the box in the garage and leave from there or if you were going to feed from the house.

I have no idea what your BIL meant by less strain on the hot lines.

If you are running 110/115V equipt. you should use two single pole breakers. A two pole breaker is for 220/240V. equipt. Two pole breakers are either internally or externally conected so that both sides will trip(hopefully) at the same time. Using them for separate 110V. receptacles may not give you the personal protection...read kids, animals and other loved ones that you need.

I have been an industrial electrician for 40 years and if you could draw a rough print of your intentions and post, I'll give you my suggestions.

Randall

[Coytee]

I guess that was confusing. The garage thing was only making a mention of the final intended use for this wire... irrelevant to this thread. I call it giving the entire picture, my wife usually calls it babbling. [:$]

Scenario: about 70' of 6-3 w/g attached directly into my main panel box (cover off and two other breakers pulled out to create the slots). Single breakers, double breakers... I had no clue. What you say makes sense so it would go into two single breakers.

I do not know how much power would be needed at the end since I'm just thinking about this. I suppose I'd have to look to the back of the equipment and see the power draw?

Regardless... the idea is to start with big wire directly into the panel, out the window across the yard. At the end of this 70' I KNOW I'd have to attach another length and don't know if I could get by with 100' or less....or more. I highly doubt I'd need 200' and could perhaps only need 50' (I've yet to even think where I'd put things). The purpose of this second wire would be to in fact, get me to the destination AND to take me down to 12g so things would easily fit on the recepticals. I'd be happy to create a junction box where they meet and solder the wires together so they'd be secure.

So each leg of this wire would be on its own breaker (red/black both hot) and the white & ground would share duty. At the end of this for simple conversation, I would put TWO different recepticals. One would be tied into the black/white/ground and the other would be tied into the red/white/ground so the white/ground are shared and the red/black are two different power sources. This way I could plug amps into one leg, projector into another leg and essentially split the load a bit.

Since I biamp I would need two amps out there. My brother in law looked at the back side of my Crown just yesterday. I think he said something about it drawing 6.5 amps or something like that. Said he was surprised at the amount of current it drew. I have two of these.

So, you'd have two Crowns, preamp, active crossover, dvd player, projector, 2 (small) motors/blowers for the inflatable screen. I think that about covers it. Right now, I've got no clue how much power that might draw. Merely wondering if the concept of sharing power down a line like that with a shared neutral and a shared ground was even possible.

When I thought of this I was thinking the shared white and ground might somehow create a problem.

[Guest " "]

"and the white & ground would share duty."

This is the weak link in the chain.

You are going to have breakers on your red and black.

Make sure that the total breaker size for your red and black is not more than the current rating of your neutral.

All the current from red and black would be running thru your 3rd unprotected wire.

[jwwrs]

I do not know how much power would be needed at the end since I'm just thinking about this. I suppose I'd have to look to the back of the equipment and see the power draw?

This is your primary concern, it's a simple add 'em all together situation.

Regardless... the idea is to start with big wire directly into the panel, out the window across the yard. At the end of this 70' I KNOW I'd have to attach another length and don't know if I could get by with 100' or less....or more. I highly doubt I'd need 200' and could perhaps only need 50' (I've yet to even think where I'd put things). The purpose of this second wire would be to in fact, get me to the destination AND to take me down to 12g so things would easily fit on the recepticals. I'd be happy to create a junction box where they meet and solder the wires together so they'd be secure.

Length after the splice IS critical. There is no need to do any soldering, just go to Lowes...or whatever and get a few wirenuts, you will not be able to use the red wirenuts simply because you are splicing a # 6 wire. You will need the larger blue wire nuts. If you can get by with a total of 4 duplex receptacles, this may very well be doable. That would give you a total of 8 individual plugins.

So each leg of this wire would be on its own breaker (red/black both hot) and the white & ground would share duty.

No they don't, the white wire is considered the DRAIN. Don't worry about what that means. The green wire is your "I DON'T WANT TO KILL ANYONE WIRE."

At the end of this for simple conversation, I would put TWO different recepticals. One would be tied into the black/white/ground and the other would be tied into the red/white/ground so the white/ground are shared and the red/black are two different power sources. This way I could plug amps into one leg, projector into another leg and essentially split the load a bit.

If you only need to put 2 duplex receptacles at the end of all this I don't think you have a problem.

Since I biamp I would need two amps out there. My brother in law looked at the back side of my Crown just yesterday. I think he said something about it drawing 6.5 amps or something like that. Said he was surprised at the amount of current it drew. I have two of these.

So, you'd have two Crowns, preamp, active crossover, dvd player, projector, 2 (small) motors/blowers for the inflatable screen. I think that about covers it. Right now, I've got no clue how much power that might draw. Merely wondering if the concept of sharing power down a line like that with a shared neutral and a shared ground was even possible.

When I thought of this I was thinking the shared white and ground might somehow create a problem.

Still your primary concern will be total amperage at the end of where your receptacles are located. After you have spliced the #6 to the #12 your problem is length, not for the #6 but for the #12. #12 copper is good for an easy 20 amps up to around 100 feet, then voltage drop starts to kick in. It is all determinate on how much over the 20 amps you are. Everything you are going to plug in SHOULD have a wattage rating listed somewhere on it. Once you know your total wattage you will be able to determine the total amperage at the end of the line. When you get that figured out, give a holler and we'll know where to go from there.

Randall

God, I hope I haven't rambled, but safety is JOB ONE

[jtnfoley]

It's pretty common to do this, and yes the neut needs to carry the sum of the hots. Not that this is exactly an code-friendly excercise in the first place, make sure to use a double breaker that's tied together... two circuits, one jacket, you don't want a hot live at the other end when you think you've killed it for maintenance!

"and the white & ground would share duty."

This is the weak link in the chain.

You are going to have breakers on your red and black.

Make sure that the total breaker size for your red and black is not more than the current rating of your neutral.

All the current from red and black would be running thru your 3rd unprotected wire.

[jwwrs]

It's pretty common to do this, and yes the neut needs to carry the sum of the hots. Not that this is exactly an code-friendly excercise in the first place, make sure to use a double breaker that's tied together... two circuits, one jacket, you don't want a hot live at the other end when you think you've killed it for maintenance!

"and the white & ground would share duty."

This is the weak link in the chain.

You are going to have breakers on your red and black.

Make sure that the total breaker size for your red and black is not more than the current rating of your neutral.

All the current from red and black would be running thru your 3rd unprotected wire.

Believe whatever you want. I'm from Mississippi and everyone knows how retarded we are.

[jtnfoley]

It's pretty common to do this, and yes the neut needs to carry the sum of the hots. Not that this is exactly an code-friendly excercise in the first place, make sure to use a double breaker that's tied together... two circuits, one jacket, you don't want a hot live at the other end when you think you've killed it for maintenance!

"and the white & ground would share duty."

This is the weak link in the chain.

You are going to have breakers on your red and black.

Make sure that the total breaker size for your red and black is not more than the current rating of your neutral.

All the current from red and black would be running thru your 3rd unprotected wire.

Believe whatever you want. I'm from Mississippi and everyone knows how retarded we are.

Ummm..... huh?

[jwwrs]

It's pretty common to do this, and yes the neut needs to carry the sum of the hots. Not that this is exactly an code-friendly excercise in the first place, make sure to use a double breaker that's tied together... two circuits, one jacket, you don't want a hot live at the other end when you think you've killed it for maintenance!

"and the white & ground would share duty."

This is the weak link in the chain.

You are going to have breakers on your red and black.

Make sure that the total breaker size for your red and black is not more than the current rating of your neutral.

All the current from red and black would be running thru your 3rd unprotected wire.

Believe whatever you want. I'm from Mississippi and everyone knows how retarded we are.

Ummm..... huh?

Sorry JT, I had been on the phone with my ex, about 10 minutes before I saw your post and I vented. Again, my apologies.

What set me off was the use of a double pole breaker to supply two seperate 110V circuits. I have seen DP breakers go bad before and burn the insulation off an entire temp. light string. The reason it did not trip was a faulty tie between the two poles. The "good" side just did not let the bad side trip.

This was an industrial and not a residential setting.

As far as using a DP to assure that both circuits are dead for maintenance, I would hope Coytee would know he's on shaky ground to begin with and this rigging would be taken apart or at least determed at the breakers when not in use.

Again, sorry for my unwarrented response.

Randall

[jtnfoley]

[] No hard feelings... I was actually thinking "Somebody got up on the wrong side of the the ex wife this morning!" []

I should clarify... DP breakers that have the silly little pinhole and pin (I've seen finish nails!) between the levers are definate no-nos... these are actually two 110 circuits in a single slot, on a single leg.

A proper 220 breaker with nicely coupled levers that'll trip simultaneously is what we are referring to.

I'll google image search what I'm thinking for claritys' sake.

[jtnfoley]

"Cheater" breaker that gets more breakers in a panel. A great way to overload a panel if ill-used. Tieing these together with a pin, and using them in a single jacket, is a big no-no.

This is the "real" two-pole breaker, which will yield 220VAC and has a very stiff tie from side to side... 1/2 trip is pretty reliably full trip.

--Edit... Big, Hairy edit: Always consult a professional electrician, respect local codes, don't run with scissors, your mileage may vary, past performance is no guarantee of future gains, etc.

[Coytee]

I would hope Coytee would know he's on shaky ground to begin with and this rigging would be taken apart or at least determed at the breakers when not in use

It would be totally dismantled.

Might not even do it if there is another way around it. The ONLY reason we'd do this is to get power out to the middle of the field. Then again, I can also get 2 runs of 100' 12g speaker wire to help minimize the length of the power lines.

Here's a picture of the house and field. I have NO idea how we'd set the screen up in the field but I envision the electronics being on "this" side of that row of trees you see next to the 'road' (that goes on out to the farm).

You can't see more to the right but this picture cuts about half of the field off.

Yikes... I think I just found a flaw in my thinking.

The projector is going to HAVE to be out "in" the field so it can be in line with the screen.

Ok... that remains an interesting point to overcome.

Originally, I was thinking to have all the elctronics by this tree line. The near side of the house, has two windows. The distribution panel is to the left of the LEFT window and it was from the right window that I was thinking we could bring the 6-3 wire out of the house, across the yard and down into the field area.

I'll look for another picture to show different angle of the field.

[Coytee]

Ok, unseen in the picture above is the row of grapes. They were behind my back as I took that picture.

This is from the other side of the field looking back to the area I was standing in the above picture.

The house is on the right and you can barely see the tree line by the road. The tree you see on the edge of the picture, is the same tree to the right of my dog in the above picture. (just for a reference point)

This gives you a better idea of what the entire field looks like. I was thinking, if you were standing here looking this way, then you would be looking INTO the projector as it would be facing this direction out in the middle of the field. I kind of forgot that I'd need power out there for the projector.

Maybe I need to get a tape measure out and get a ballpark idea as to the length I'm talking about.

I could always put the projector at the treeline and shoot the movie away from the house.

[whatever55]

So now you will have to get a trailer to move those big black boxes out there......

[Marvel]

Yikes... I think I just found a flaw in my thinking.

The projector is going to HAVE to be out "in" the field so it can be in line with the screen.

That's usually the way it works, unless you can do some tricks with smoke and mirrors (mostly mirrors). []
Bruce

[Coytee]

So now you will have to get a trailer to move those big black boxes out there......

Ahhh....not so fast Tonto!!

I also happen to own a JCB full sized industrial front loader/backhoe [H] Comes in handy when a tree falls across our access road or I move boulders the size of a desk around for our retaining wall or when the wife wants her petunias replanted [H]

Since it would probably be me alone moving these things, what I'm envisioning is sliding them into my front bucket one at a time (bucket is eight feet wide) and taking them back to the trailer where I then slide them out after using said bucket to raise them to the appropriate height.

So, my "hand truck" will be Brutus!!

This is why I'm not concerned about banging them up....because they ARE going to get banged up.

[djk]

"and yes the neut needs to carry the sum of the hots."

The neutral carries the difference between the hots, plus any harmonics. If the power factor is unity and the same load is on each leg, the current through the neutral is zero.

[twistedcrankcammer]

Richard,

One point that I only saw touched on by rwwrs is that the length of that #12 is going to be critical. The longer the wire, the more resistance it has, the more resistance it has, the more heat it creates, and the more the voltage drops.

Not taken into account here by any of these guys is how far off of the road you are, and what your actual voltage is at your service. Add onto this fact of a possibly rather long extension cord, and the voltage drop could be hard on your amplifiers.

Roger

[djk]

500' 12ga = .794R, 140' 6ga =.055R, total =.849R

If the load was balanced on both legs the equivalent series resistance would be half (neutral carrying no current).

An unbalanced 14A load per leg would have a 10% voltage loss, which would be fine. 28A total at 108V (10% low) is over 3KW. I've done PA gigs with this kind of power and voltage, and had no problems. Don't use amplifiers with 'trick' power supplies (Carver, Soundcraftsman, etc).

At clipping, a Crown Macro-Tech 2402 draws about 5.7A on Rock & Roll (30% duty cycle) at 8R, about 8.3A at 4R.

The better balance you can get between the two legs, the less voltage drop there will be, and the more power you can draw.

[twistedcrankcammer]

500' 12ga = .794R, 140' 6ga =.055R, total =.849R

If the load was balanced on both legs the equivalent series resistance would be half (neutral carrying no current).

An unbalanced 14A load per leg would have a 10% voltage loss, which would be fine. 28A total at 108V (10% low) is over 3KW. I've done PA gigs with this kind of power and voltage, and had no problems. Don't use amplifiers with 'trick' power supplies (Carver, Soundcraftsman, etc).

At clipping, a Crown Macro-Tech 2402 draws about 5.7A on Rock & Roll (30% duty cycle) at 8R, about 8.3A at 4R.

The better balance you can get between the two legs, the less voltage drop there will be, and the more power you can draw.

What does Richard have available at the load center prior to the added resistance, this can be alot different in the country. My Nakamichi PA-7s have multiple built in protection circuits and wont power up on alot less cord than that. I own a small farm and I'm in a fairly rural area. I can't even get cable. My parents driveway is 0.4 miles long and the service drop is slightly longer. Richard looks to be considerably off the road as well.

Roger