Stuff Electricians Should Know!

If you’ve been in the business of electricity for more than about a week then I’m sure you’ve heard the terms “Single phase” and “Three Phase”.

So, what do they mean?

A single-phase AC circuit has either one or two wires connected to the source of electricity. For 120 volts you have a “Hot” and a "neutral". The “hot” conductor is connected to the power source and the “neutral” or “grounded conductor” returns to the source.

For 240v you have two “hots” connected to the source. Even though you have two “hots”, it is still considered “single phase”.

So adding up the wires, you’ll have 2 hots and a neutral giving you a 120/240  single phase, 3 wire system.

So what about 3 phase?

What is backfeeding?

The simplest explanation for backfeed is when power flows in the opposite direction from its usual flow or when voltage is present on a conductor or associated equipment after it has been disconnected from its normal source.

In this episode I'll quickly cover several different types of grounding electrodes.

Todays question was sent in by Mike D.

As I have been scouring the googles, trying to find topics of interest that would help out, I keep running into a fairly common question. It's easy to forget that what may seem common to one person, isn't so common to the next.

Especially to the apprentices that are just coming into the industry.

So I thought this appropriate as a refresher to some, and as fairly new information to others.

The question:

"What is the difference between MCM and KCMIL? Is it a regional thing or is there some difference that I'm missing?"

The short answer:

They are one and the same thing.

Today’s episode is just a heads up, or a safety warning to all of you who might work alongside the utility company at some point in time.

On occasion, the utility company might require you to install what is called a bypass meter socket. In our area they require them to be installed on commercial or industrial buildings, and oddly enough, detached garages or shops if you aren’t running power to them from your house.

What is a bypass meter socket you might ask? Well, let me tell you. There are a few different kinds, but they all accomplish the same thing, which is, when the utility company pulls the meter out of the socket, they can bypass the meter socket and still allow electricity to flow from the line side to the load side and supply power to the shop, complex, or in today’s story, the furniture store.

Here's today's question. What is the difference between lumens and watts?

In the world of lightbulbs, especially with incandescents, you were probably at one time, and maybe you still are, used to choosing your lightbulb by the wattage listed on the package.

The wattage gave you a decent indication of how bright the bulb was going to be. In a nut shell, the more watts, the brighter the bulb.

Now that LED’s are coming on strong, things have changed. An LED that uses 60 watts is no where close to a 60 watt incandescent. In fact, a 60-watt LED might just burn the retinas out of your face.

Because LEDs are designed to use less energy they will of course have a lower wattage rating. So now you don’t really want to use the watt rating for your brightness like you probably did before.

I had the opportunity of speaking with an electrician who discovered what the NEC requirements were to change out a residence full of two wire non grounding type receptacles, to three wire, grounding type. 

When trying to help someone decide what fixtures to use, we came across the designation "damp location" on the fixture spec sheet.

I thought this would be a great subject to touch on today.

So I was talking with a project manager the other day and he was having trouble getting some submittals approved for a hotel.

One of the issues that came up was that the gear company wanted to know if the gear could be series rated to save some money or if it had to be fully rated.

The project manager had no idea what they were talking about and I was a little confused as to why he at least didn’t know at a basic level what the difference was.

So I thought I’d share with you today what the difference is, at least on a basic level.