I am sure there are not many of us that have not been the brunt of a joke that took us unsuspectingly by using terminology that we were not familiar with. While we went along willingly looking for the "left-handed screwdrive", when it comes to electrical work don't let your electrical contractor try to bedazzle you with terms and acronyms that leave you confused or unsure.
It is important that you let your electrical contractor know what you do and don't understand when it comes to electrical work. When I talk to a client, I have to balance giving them the information they need to make informed choices while not treating them like some two year-old who is just learning the primary colours or how to count.
While it is not likely you will be able to stand toe-to-toe with your electrical contractor in a terminology battle, there are a few basic things that will help you through that conversation to make sure you are getting the work done that you want, or at least be able to compare the options presented when comparing electrical contractors to do your work.
So here is a starter's list on the basics of electrical terminology that you should be familiar with as a homeowner. Fair warning to my fellow tradesmen; I know my definitions will not be 100% technically correct but I would rather provide more common language than be technically correct.
- Dedicated Circuit - This is used to describe a circuit that normally only has one receptacle on it. An example is a refrigerator circuit. In a majority of modern installations there is a breaker labeled refrigerator. There are no other lights or receptacles attached to that breaker.
- Split Receptacle - This is a receptacle (usually found on the kitchen counter) where the bottom half and the top half are each dedicated circuits. So while the refrigerator receptacle is good for 15 amps, a split receptacle has 15 amps available on each half. That is why you can plug your kettle and toaster in at the same time in the kitchen, yet if you tried that in the living room the breaker would trip.
- Insulation Contact (IC) - Potlights are more common than ever. Any potlight that is installed where it is going to be touching insulation must have an IC rating.
- Plug vs Receptacle. A plug is one end of an extension cord, a receptacle is usually on the wall.
- Three-way Switch - Somewhat contrary to the name, a three-way switch controls a light(s) from only two positions. A typical example of a three-way switch would be at the top and bottom of a stairway.
- Fuses vs Breakers - One could argue that they essentially do the same job, which is protecting the wire from excess current; however breakers are a mechanical device that can be reset while a fuse is a one-time device. For the most part fuses and breakers come in standard sizes of 15, 20, 30, 40 and 60 amps.
- American Wire Gage (AWG) - This identifies what the "thickness" of the conducting portion of the wire is measured in. The higher the number the smaller the wire. A #14 wire is standard for must circuits in the home. You might find a #10 wire (larger) for your dryer receptacle and a #8 wire (even larger) for your stove receptacle.
For the last three terms (resistance, current and voltage), I will try to use the water analogy to explain their difference. I have found this works well when teaching apprentices the difference and helps them to visualize what is happening electrically.
If you can imagine a piece of wire as a pipe in your house that is full of water...
- Resistance is commonly referred to as ohms. Think of this as the size of the interior of a water pipe. A smaller pipe has greater resistance then a larger pipe. A smaller pipe can only physically handle so much water volume before it is maxed out. When wiring up a circuit, we look at how much electricity is needed for that device and we size the wire to match the demand. Unfortunately we don't have the luxury of looking at it like a pool or bathtub, we can't wait for the electricity to fill up before we use it; we need it instantly.
- Current is commonly referred to as amperes / amps and is the same principle as litres per minute. A specific size wire can only handle so much volume of electricity before it starts to break down. It would be like attaching a garden hose to a fire hydrant to fight a fire, it would not take long for the hose to break apart simply because there is too much volume required to fight the fire. So current (amps) is the amount of electricity required to make things work.
- Voltage is equivalent to electrical water pressure. To be able to move the current through the wire it needs to be "under pressure". In your house, we like to keep the electrical pressure pretty steady, but if we turn on too many things we start to see a drop in pressure such as lights dimming or motors starting to run slower.
So there are some terms and definitions to help you through conversations with your electrical contractor. If you get stuck answering a question, you can always pull a line from the movie Mr. Mom (1983) and say "220, 221 - whatever it takes. " then give him a nod and see where it goes from there.Posted by: John Kuehnl-Cadwell