Extreme weather such as ice storms and heavy winds are a common cause of power outages. During an outage, a properly-sized and well-maintained standby generator can be convenient to have on hand. Electricity can be restored within minutes with a manual-start generator, or in seconds with an automatic-start unit. It is most important if you have a generator to have it professionally installed to protect the safety of our line workers, your home and appliances.
Properly Sized Generator for Your Home
Most portable generators for homes range from 4,000 to 12,000 watts. Their size and cost depend on how many electrical devices you want to run at the same time.
Power requirements for typical home appliances
These appliances need a total of 4,700 watts to run, however a 4,700-watt generator is not large enough. Appliances with motors generally need up to 4 times as much wattage to start as they do to run.
For example, an 800-watt generator would keep the refrigerator going, but it would take a 2,500-watt generator to start it. If a generator is too small to handle start-up watts, it can slow down when overloaded, and possibly starve motors of voltage and damage them.
Turn devices off to allow larger loads to start. After starting the generator, turn on circuit breakers to your motors first — one at a time, from largest to smallest. For example, first you would turn on the circuit breaker for the refrigerator, followed by the well pump, furnace, and sump pump. Consult your generator supplier to ensure that the wattage and horsepower rating are sufficient to handle your essential loads.
Essential Loads Panel
An essential loads panel looks like a smaller version of your main breaker service panel and should be mounted close to it. Essential devices you want to run with your generator (the essential loads) are disconnected from the main service panel and wired into the essential loads panel. The panel generally has from 6 to 10 branch circuit breakers available to handle your essential devices. The essential loads panel is wired to a transfer switch, which has two positions:
- Electric position – Used during normal operation. Power from your main panel runs to your essential loads panel to feed your essential loads.
- Generator position – Used during a power outage. Power from your generator runs to your essential loads panel so that it can feed your essential loads.
The Transfer Switch
The transfer switch is a key safety essential and mandatory under the Canadian Electrical Code. It sits between your essential loads panel and your main service panel. The transfer switch blocks the generator from sending power back into the power lines. Without a transfer switch in place, our line workers are at risk of injury or death.
Have a licensed electrician complete all electrical work that connects your transfer switch to the electrical system look after necessary inspections, and ensure that all electrical codes are met.