Wiring Decisions for Dummies - The Freelance Files MMCCXXI

15-amp breaker

The nice people at eHow¹, apparently thinking that they can fool all of the people all of the time, require that their contributors provide a short bio so that readers know their work is... "authoritative." Unfortunately, that's not always true: take the case of the post a staffer recently turned up at the mother site², a post attributed to Mark Dennis entitled "Adding an Electrical Outlet From a Light Switch." Given that Dennis claimed a "two-year electrical engineering degree," one would expect that his facts would be accurate.

We said "facts," didn't we? We hadn't even gotten to the meat of Dennis' instruction set when we ran across this heaping pile of bogosity:

"You'll need a receptacle -- the electrical outlet itself. They come in 15 amp and 20 amp. I suggest using a 20 amp outlet, so you won't have to worry about the amperage of the items you plug into it."

Yes, this moron (AA degree or not) actually thought that the receptacle has a say in the amperage of the circuit. No, you ignorant schmuck, it's the breaker and the wiring, not the receptacle! The only differences between 15- and 20-amp receptacles are that a 20-amp receptacle can take 12-gauge wire and has one T-shaped slot. Plus, those appliances have a wattage rating, not an amperage rating: amperage equals total wattage divided by voltage. Sheesh: this dude's community college needs to claw back that apparently useless degree!

Mark's first step, which is as it should be, is to turn off the circuit at the breaker box. Right then you'll know whether the circuit is 15 or 20 amps, because breaker switches are labeled with the amperage (see image above). Whaddanidjit!

Most of what Dennis tells people to do to wire the new outlet is correct, or would be if the switch was 1) wired in accordance with code and 2) isn't an end-of-run switch. If number 2 applies, the wiring coming into the box won't consist of,

"...two white wires joined with a wire connector..."

...and neither will

"The switch... have two black wires connected to it."

In that case, there's one black wire connected to the switch and one white wire that has been "recoded" black. You can't add an outlet to this switch. Period. But Mark never mentioned that (probably didn't know it).

We're also a little underwhelmed by his instruction to,

"...connect your receptacle's black wire to the same screw as the wire that goes to your electrical panel..."

Frankly, we think best practice would be to connect the two hot (black) wires and a pigtail, then run the pigtail to the hot terminal on the switch. Mark's way would work, of course, but seems sloppy to us.

Oh, and one more thing our Dumbass of the Day didn't mention; either because he didn't consider it or didn't know such things exist: What about a three-way switch: which wire is hot? And while we're at it, what do we do with the ground wire (which is rarely insulated with green in a 120-volt circuit; it's usually bare)?

Considering that Dennis seemed to think that you just "run your wires from the switch box to the outlet box" like you might run a hose into your garden, we weren't all that impressed to begin with.

¹ Actually, the parent company Leaf Group...
² eHow.com, also known as "the mother lode of misinformation."

DDIY - WIRING