Next Year's Christmas Lights

[eccentrictinkerer]

I don't understand what part isn't to code or inherently dangerous.

When you tap into a dryer outlet, you are on a circuit generally fused, or breakered at, at least 30 amps. Your extension cord and lights are usually rated at 15 amps. If you get a short anywhere in the circuit, the wire will become your fuse. 30 amps at 120 volts is 3600 watts which is the equivalent of 3 toasters.

The code part is that you may not use wire (ext. cord) rated at 15 amps on a circuit that can provide 30 amps. I'm an electrical engineer (retired). I started a handyman company (Husband For Rent) 6 years ago and I do a good bit of wiring. My customers who have my work inspected have never not had the work approved.

A cheap sub-panel will make everything safe (BTW, in my state, all garage outlets must be GFI'ed, FWIW). I got a Sq. D. panel with 4 breakers (8 slots) for $48 at the home center for my garage. I used a 50 amp - 240 volt circuit that I put in for an old arc welder. I now only use a 120 volt MIG setup, so the 240 volt dryer-type outlet just took up space.

[Tom Slick]

He mentioned in his first post that it is a 20A 220v circuit, although I agree with you that 30A is the most common. If I am following you then you could never plug anything lower then 15a into the wall, that would mean that you couldn't plug a single strand of lights into the wall, never use a 16ga cord, etc. I was taught that the purpose of circuit protection in residential wiring is only to protect what is in the wall, not the appliance that is plugged in.

I'm not trying to be argumentative, I just want to make sure I am understanding you correctly.

[eccentrictinkerer]

He mentioned in his first post that it is a 20A 220v circuit, although I agree with you that 30A is the most common. If I am following you then you could never plug anything lower then 15a into the wall, that would mean that you couldn't plug a single strand of lights into the wall, never use a 16ga cord, etc. I was taught that the purpose of circuit protection in residential wiring is only to protect what is in the wall, not the appliance that is plugged in.

I'm not trying to be argumentative, I just want to make sure I am understanding you correctly.

Sorry, I completely missed the 220 volt, 20 amp reference. As I believe others have mentioned, a person should have a separate neutral back to the main box for each circuit. That would satisify code in most areas. Also, separate breakers for each hot would satisfy code.

BTW, a little off topic, I learned something interesting about updating wiring. My home is 90+ years old and there are a couple of runs of old knob and tube wiring I can't get at to replace. One of the guys in the Borg electrical section told me I could use a GFI outlet so that I could have three-wire "grounded" outlets. I looked it up and he was right!


An easy and fairly cheap update.

[pierhogunn]

okay, so a sub panel, does anyone have any simple diagrams ( I never was good at word problems) that I can use to take to Lowes or BORG and grab parts off the shelf?

Would there be any "good ideas" that I should incorporate into my sub-panel on a stick

like can I put this thing in a pelican case so that it can live outside next to the house during the Holiday season

or should I just hang this thing on a nice dry piece of plywood, and mount it on the wall next to the receptacle?

Or even better, if you were going to do this, in a step by step manner how would you do this ( this may prove of some use for others who have this sort of Dryer connection in the garage and nothing to do with it ya know sorta like a single long power cord for a rolling workstation with the BT3K and dust collection built into it...

[LarryG]

Our EE consultant commented on the existing dryer outlet on this circuit. The breaker is matched to the wire size (because as Tom mentions, the sole purpose of a circuit breaker is to protect the wiring in the wall), and the outlet is matched to the breaker. A 30A outlet on a 20A circuit is technically not code.

David, balancing the load on the two legs of the panel is basically just to make sure you're getting the full benefit of the panel's capacity. In an extreme case, if all the breakers were installed on one leg only (making 240V circuits impossible), you'd only be making use of half of the panel's capacity. Assuming a normal house's load (again, excluding the usual 240V stuff), you'd probably be popping breakers left and right because the single leg is powering everything. Moving half the breakers to the other leg, dividing the load more or less equally between the two legs, would eliminate this problem (assuming, of course, the total load doesn't exceed what the panel can deliver).

The subpanel suggestion is interesting and certainly won't hurt, but if there will be only two circuits at 20A each, IMO all you'd be doing is duplicating what is already there, at the main panel. OTOH if you fed the subpanel with the 20A 240V circuit and put in, say, two 15A breakers on each leg, to give you the convenience of four separate 15A circuits, the subpanel is the way to go.

[pierhogunn]

anyone have the electrical specifications on a 100 bulb strand of lights, a 150 bulb strand of icicle lights, and