Wiring, circuit breakers and panels

There are a number of points that a homeowner must understand before having a home wired. Most important is not to do your own wiring if you aren’t qualified. Having some knowledge of electrical wiring enables you to recognize the meaning of different procedures when they are being explained to you by an electrical contractor.

Learn about the local electrical code.  It tells you what can and cannot be done.   Your local electrical inspector enforces the code. Do not perform any wiring without first obtaining a permit. The permit and subsequent inspection is for your own safety.

If you are doing a major wiring job, such as a rec room or rewiring the main floor of your home, first make a plan locating outlets.  The location of outlets will be in combination with your preferences and the code requirements.

When wiring, do not put the entire main floor or rec room on one circuit.  If the single fuse or breaker goes, then the entire floor or room will be in the dark.

When purchasing electrical materials and fixtures, always look for the symbol designating CSA approval. This doesn’t necessarily mean that the items are top quality, but simply that they meet the minimum standards when used for the purpose they are intended.

Not all homes with inadequate outlets or lighting need to be completely rewired. All that may be necessary is to install additional circuits. These additional circuits may be connected to an existing service panel.

In some older homes, the panel may have either fuses or a thick-type of circuit breaker. Some of these circuit breakers can be changed to new thinner models.  And in some cases, the number of circuits can be increased in the existing panel.

Remember that each circuit has its own fuse or breaker.  Never attach two circuits or two wires to a single fuse or breaker.

If you extend an existing circuit remember that the maximum number of plugs or lights, not counting switches, that can be installed on one circuit is 12.  This will apply to areas of the home such as the living room, family room, rec room, bedrooms and hallway.  

There are exceptions to this rule and they deal with specific areas of the home such as the kitchen.

 The electrical system can often be updated in an existing home and provision can be made for additional circuits by installing a sub-panel.

Usually, a 220-volt line can be run into the sub-panel to provide an additional four circuits. These additional circuits can accommodate up to 48 more outlets in the home. The number of outlets is determined by the location and use of the outlets.

In some older homes, a new service has to be installed, especially if you are rewiring the entire house, if you have built a home addition or are finishing a basement rec room.  In this case, I highly recommend that an electrical contractor be consulted to determine the size of the new electrical service.

Many older services are only 60 amps.  Most new services are either 100 amps or 200 amps.  They can go as high as 400 amps in the case of homes with electrical heating. A 400-amp service is usually required in a new home if a pool is installed with pool heaters.

The size of the electrical service is based on the square footage of the home, the type of heating unit or units and the number of circuits needed.

Changing an electrical service is something a home handyman is neither qualified to do or should do —  consult your electrical contractor.