Wiring "new" electrical circuit

[Joseph Meehan]

How are you running the new wire? It is going in a wall, in an attic, basement? Do you know the requirements for securing the new wire?

[John W. Wells]

I agree with Tim on his three points--and would suggest an easily read, well-illustrated book published by Sunset, "Complete Home Wiring." It will give you an idea of whether you're up this and other electrical wiring projects.

That book, a couple questions here, and a call to the local planning department (electrical inspector) gave me the wherewithal to wire my

2-story, 1400 sq. ft. workshop, including 240v for a kiln, 120v receptacles everywhere, and 3-way switched lights. No previous experience.

--John W. Wells

[George E. Cawthon]

While you at why not use 12 gage wire? According to the copper institute larger wire is better for electronic equipment to help reduce stray emissions. Don't know if that is true, but I would always run a minimum of 12 gage wire even when you are making a 15 A circuit, 10 gage for any long runs. The cost difference is negligible but I admit that working with 10 gage is a real pita.

[PJx]

???? There is no need to secure the new wire. Gravity will keep it from floating off into space.

No inspector will see the new wire. It will be installed in the privacy of ones own home. Noone will know. Should an inspector or anyone else spouting nonsense about 'code' come into the home without explicit permission, they will be killed, butchered and eaten.

Government intervention is NOT good. PJ

[Doug Miller]

Gravity won't keep it from jerking a connection loose when someone trips over it while stowing something away in the attic.

Sometimes it is -- as when it deters or prevents my idiot neighbor from following unsafe wiring practices that result in burning _my_ house down _as_well_ when _his_ catches on fire. That's part of the price you pay for living in a city: your freedom to be stupid and careless is limited by the likelihood of inflicting the consequences of same upon your neighbors. If you wish complete freedom to be stupid and careless, go live where you have no neighbors who might be harmed.

-- Doug Miller (alphageek at milmac dot com)

How come we choose from just two people to run for president and 50 for Miss America?

[Joseph Meehan]

Sorry, but your message just proved you are not competent to do your own wiring. What you don't know can cause a fire and does so almost every day in a home where someone did not know or did not care about code. Code is there to keep you and others safe. Only a *&(& would ignore it.

I might add that if for some reason an inspector does come in and sees such stuff, you may have a bigger problem than you expect. If your home burns because of it, your insurance (do you have insurance?) can refuse to pay.

[zxcvbob]

Secure the wire in the attic, and everywhere it is accessable. (In the attic, it is more of a trip hazard than a fire hazaard.) Use an outlet box that has clamps where the cable enters the box. If you're running wire inside an existing wall cavity, you don't need to secure it inside the wall

-- the clamp in the box is enough. Or do you suggest knocking a huge hole in the wall so you can staple the wires?

Bob

[HA HA Budys Here]

Sure. And all taxation is theft, and any government imposed l;aw or restriction greater than absolute anarchy is wrong too, eh?

[Chris Lewis]

According to George E. Cawthon :

The copper institute is trying to sell more copper. Does that give you a hint?

Emissions from 60Hz in an ordinary household circuit is largely cancelled out in _cable_ because the two wires run so close together, and the magnetic flux is in opposite directions.

Secondly, the amount that "escapes" is going to be primarily dependent on wire _spacing_, and a lesser extent the diameter of the wire. The smaller the spacing/diameter the better. The wire spacing in cable on 12ga is going to be insigificantly different than 14ga (because the insulation thickness is the same), and if anything, would be _more_. And of course, the copper diameter is _thicker_ in 12ga.

The real reason for using 12ga on a 15A circuit is to reduce voltage drop on long circuits when you're running high current.

On a circuit dedicated to high fi gear, unless you have whomping humongous amplifiers, it'd be overkill. And if you were doing that, you'd might as well go with a 20A breaker.

[Except in Canada, where 20A general purpose circuits with ordinary 120V outlets is still illegal. But maybe not for long.]

If you have to go to 10ga for a 15A circuit, something's very strange...

For several hundred feet maybe. But not inside a house. Unless it's a REALLY BIG house.

[HA HA Budys Here]

At least it's a somewhat "respectable" product plug. Unlike the "Oxygen free Monster cable" they sell to unknowing audiophiles and kids installing "systems" in their POS Toyotas and Hondas, where the speaker cables are larger than the battery cables!

Not that the equipment wouldn't already include it, but wouldn't you think a

15a circuit might better protect Hi-Fi equip?

Problem with up-sizing wire in a residential, or sometimes commercial enviroment, is dealing with the resulting box-fill requirements.

[Larry Silkaitis]

In actuality, oxygen in copper significantly increases its resistively. All electrical wire is OF copper.

Larry

[George E. Cawthon]

Yeah I know they want to sell copper. Don't have the expertise to dispute their statment on using larger size wire to reduce stray emissions, I just accepted it.

Yep, the main purpose of larger wire is to reduce voltage drop, but it isn't several hundred feet before you need #10 wire. For a 3% voltage drop--just 80 feet reqiures #10 wire, i.e., 80 feet at 12 amps which is about a 1 hp motor. Top line vacuums will pull that much. My Hoover is rated at

12 amps and it comes with a 25 foot or longer cord. Plugged into a 15 A circuit, which is 14 ga will cause a dimming of the lights when the motor starts but the lights are still dim somewhat when it runs. I haven't checked the voltage on the circuit with a meter yet. But that means that there is a waste of efficiency and possibly a shorter life for the motor.

There is no reason to use the standard #14 wire except that it is a few buck cheaper and it is easier to work with. Circuits in many houses are longer that 80 feet from the pannel to a receptacle, so a wire heavier than #14 makes sense if that circuit is going to be loaded up, especially with a large motor (read vacuum cleaner). Forget the idea of protecting the wire, which is what the standards do, size the wire to protect the appliances and to increase efficiency (read reduce electricity cost).

[Chris Lewis]

According to George E. Cawthon :

Not quite. 160 feet (2 80' conductors) of 12ga at 12A is 3.1 volts drop. Slightly less than 3%. Note that the code limitation for permissible panel-to-outlet drop (at least in the CEC) is actually 6%.

True enough, but I'd comment that if the lights are still dim after startup surge it may require a bit more attention.

Again true enough. But at least for the OP (dedicated circuit for an entertainment centre), the amperage isn't going to be high enough to make "efficiency" a consideration.

[George E. Cawthon]

I just used the online calculator that some put in a reply. You're right about the NEC, but I'm not concerned about the minimum, I want something better. And since power tools may have their own extensions (e.g., the vacuum), figuring just panel to receptacle isn't very conservative for a motor.

here isn't much I can do about the circuit that show lamp dimming. All the connections at the receptacle boxes and the panel appear ok (and I don't have any aluminum wire), so it appears to just be a problem with wire size and length.

You're right on the efficiency, but who knows how long that circuit will be dedicated to powering just an entertainment center.