Saturday, April 09, 2011

A Lesson in 'Lectricity.

Okay. What went wrong with the kitchen circuit? A fairly simple circuit with just one light and a wall switch, it should have been a no brainer. Yet every time we flipped the circuit breaker on, the light would come on even though the wall switch was turned off. And, when we flipped the wall switch to the "On" position, the circuit breaker would trip cutting off power to the kitchen, the storage room and the bathroom.

Mark, who says he is a functional illiterate in the 'lectricity department, could figure out why. I drew a diagram--twice!--and looked at it over and over and couldn't figure out why. It was frustrating. I knew there was something "different" that had to be done but I couldn't remember what. So we agreed to let it slide for the time being.

I headed home to PA and wasn't more than twenty miles from the Bolt Hole when I realized what was wrong. Let me 'splain:

Draw two parallel lines about an inch apart. One will be the black ("hot") wire and the other the white (neutral) wire.

between the two lines on one end draw a square and label it "CB" for circuit breaker. Half way down the lines and between them, draw a circle and label it "L" for light. At the other end of the parallel lines draw something that looks like a slash so it touches one or the lines but not the other. Label that "S" for switch. Look at your diagram for a moment. Those familiar with electric circuits can spot the problem already. If you can't, welcome to my world.

When we hooked it all up and connected to the power source, the circuit breaker was in the "Off" position as was the switch. (We're slow. Not stupid.) When we flipped the circuit breaker to the "On" position, the light came on even though the switch was turned "Off." When we then flipped the switch to the "On" position, the circuit breaker tripped. We did this three times just to be sure and even went so far as to disconnect the switch and flip the black and white wires thinking that might be the problem.

After beating our heads against this particular brick wall (which, in reality, had as much density as fog) we gave up and disconnected the circuit. We would "think on it," we said.

I packed up and headed back to PA and twenty miles into my trip, it hit me. Look at the diagram again. When we had both the circuit breaker and the switch turned "Off," the little electrons were lined up waiting to into the circuit. [Disclaimer: Yes, I know electrons do not actually flow through the wire. That alternating current is more like a long, thin mosh pit of electrons pushing and shoving back and forth. And direct current is more like dominoes where the pushing is all in one direction. But, for the sake of describing what was going on in the easiest manner possible, play along with me here. Okay?]

Okay. These electrons were beating on the door just wanting to get into the circuit. When the breaker was thrown to the "On" position it was Black Friday! Through the gate they streamed and up the black wire to where the line diverged. There, they saw a sign saying "Bridge Out Ahead" and they were detoured to the light. They shrugged their little shoulders and moved reluctantly through the little twists and turns in the tungsten filament of the 60 watt bulbs before reaching the white wire and heading back to the circuit board. There, they were given a pat on the back and a "Job Well Done" commendation for the light and heat they had produced in the bulbs. That's why the light came on even though the wall switch said "Off."

When we then flipped the wall switch to the "On" position, the electrons got the divergence point and the "Bridge Out" sign was not there! They could continue on through the switch and directly back to the circuit breaker via the white wire. No pain. No strain. No light. No electricity. Yet they expected to be rewarded when they got back to the circuit breaker. But Mr. CB was having none of it! He flipped out and slammed the gateway allowing no more electrons into the circuit.

Putting things together the way we had had 1- created a circuit with a light but no switch and 2- a built in short every time we flipped the switch to "On." Dummies!

Yet easily corrected. We had been thinking all black wires get hooked together and all white wires get hooked together. We were thinging in black and white. What we needed to do was remember our current President. the post racial one. While half black, he is also half white. Looks can be deceiving. What we needed to do was run the black wire from the power source to the black wire in the light and then the white wire of the light to the black wire of the switch. From the switch, the white wire would connect directly to the white wire heading back to the ciruit breaker (power source).

The ladder like diagram with the large circle in the middle labeled with the "L" would instead have the circle along one of the two parallel lines. Like this:
------------0L----------
-------------------------

This would force ALL the electrons through the light when the switch was moved to the "On" position. No more free lunch. If you want to move through the circuit, you'd have to wait for the bridge to be open and then work!

It'll take me half an hour to make the correction. A real Gibbs' slap moment.

6 comments:

Richard said...

Sure hope you don't have to wire any three way switches...lol.

joated said...

Richard, I have done them in the past...but only with a published diagram from a home improvement tome in front of me. Trying to do one off the top of my head would probably blow more than the circuit breaker.

Anonymous said...

The solution you described will, I believe, result in a continuous "HOT" black wire at the light. You're not supposed to switch the neutral (white) but rather, switch the hot wire using the two wires from the switch joined to the black at the light and the black incoming from the breaker panel. Tape the white wire at the switch and the light to indicate that it's now a 'hot" wire.

Leatherneck

joated said...

I think I got you on that, Leatherneck. ROute the electricity so it goes directly to the switch on the wall then put the light on the back flow FROM the switch instead of on the flow TO the switch as I described. That way, when the switch is "Off" there will be no current in the light.

Anonymous said...

I may have described it wrong. Here's the expert version of your wiring setup:
"As in the last example we are working here at the end of the circuit. The source of the the circuit in our diagram is coming up from the bottom. The white wire is attached directly to the white wire on the light, while the "hot" black wire is attached to the white wire (painted or marked black with electrical tape) coming from the switch."

That comes from this site, where you can find a diagram: http://www.indepthinfo.com/wire-switch/light-switch.shtml

Leatherneck

Anonymous said...

From this site: http://www.indepthinfo.com/wire-switch/light-switch.shtml

which shows a diagram of your situation:
"As in the last example we are working here at the end of the circuit. The source of the the circuit in our diagram is coming up from the bottom. The white wire is attached directly to the white wire on the light, while the "hot" black wire is attached to the white wire (painted or marked black with electrical tape) coming from the switch."

Sorry for any confusion.

Leatherneck