Generators

In your search for the right generator, you may be asking yourself a few questions. What size of generator should I get? Portable or standby?  How expensive is it? In this article, we are going to get to the bottom of some of the important questions that will aid in your decision of which generator is right for you.

What size of Generator should I get?

There are many different generator sizes depending on your situation. My advice is this: Don’t let someone sell you a whole home generator if all you want it for is to power a few outlets and lights. And don’t buy yourself an 8000-watt portable generator if you want to be able to live like the power never went out. In other words, don’t buy a generator that’s too big for your purposes, and don’t buy one that’s too small.

“But how do I know what size I need?”

This is a loaded question. If you have a good understanding of power and electricity, you may be able figure this out on your own. If not, then it might be a good idea to talk with a Licensed Electrical Contractor. But for the moment, I’ll do a quick run through to help you understand a little about the generator sizing process.

 To determine the size of generator you need, you must understand a little about power(watts) because that is what generators are rated in. Power usage is what will determine the size of generator you will need. Every appliance or motor uses a certain amount of power (check nameplate). Power adds up, therefore, if you are using multiple devices at one time, the power usage will rise. Here’s an example: Your stove takes 6000 watts, and you turn it on. At the same time, you decide to dry some clothes in your dryer, which takes 4000 watts.  This means, at one point in time, you will be using 10000 watts of power. Does this mean you need a generator capable of delivering over 10000 watts? Not necessarily. If you can avoid using multiple appliances at once, you can limit the amount of watts used at any one time. If, however, you don’t want to worry about this, then a larger generator might be a worth while investment. Most homes have a main panel that’s rated for 100 amps, which is equivalent to 24000 watts. If you want to live normally during a power outage, then get a generator capable of delivering this, or close to this.

Overall, there are a lot of factors to consider. It really depends on what you want and how much you want to spend. As the electrician determining the size of your generator, I would need to consider all of these factors before I could determine the wattage needed.

What Kind of Generator should I get?

Everyone loves a pros and cons list.

Standby Generator Pros
–  Option to auto-start when power goes out
–  Everything wired right to your panel
–  Generator comes on automatically during storm
–  Fuel source is a very large propane/diesel tank or natural gas from the road. It won’t run out during extended power outages
–  Can power whole home (size dependant)
–  Very reliable if properly maintained

Standby Generator Cons
–  More Expensive per unit
–  Permanently installed at selected location
–  Generally used for emergency use
–  Need to pay an electrician(power), and HVAC/Plumbing company(gas) to install
–  Should be maintained by qualified service personnel
–  If not properly maintained, they may have problems during power outage

Portable Generator Pros
–  Cheaper per unit
–  Can be stored when not in use
–  Can be used for non-emergency
–  Don’t need to pay for installation (in some cases)
–  Can be maintained by owner|
–  Reliable for short periods

Portable Generator Cons
–  Won’t auto start with power outage
–  May Require use of extension cords
– Set-up is likely during a storm
–  May need to re-fuel if power outage is prolonged. Fuel may not last the night
–  Unable to power many devices
–  Depending on type, may not work with electronics

Transfer Switch

No matter what generator you decide on, if it will power a panel in your home, a transfer switch is required. Basically, a transfer switch creates an isolation between the generator power and hydro. Without this isolation, there would be a few major hazards. This transfer switch can switch over automatically or manually, depending on what you want.

Automatic Transfer Switch (ATS)

An ATS works as the name suggests: automatically. It offers a more convenient option when compared to a manual transfer switch (MTS). As soon as the power goes out, the standby generator will kick on, and the ATS will switch over and allow generator power to power your panel. Because it switches over, it will also prevent the generator power from back feeding to the grid.

Manual Transfer Switch (MTS)

An MTS requires the user to manually switch the power from utility power to generator power at the panel. While this works if you are home, if you are away then your home will be without power until someone is able to do the switch-over. As with an ATS, it prevents back feeding to the grid.

Dangers of a Portable Generator

This is not an installation guide, nor a push to buy one generator over the other. I believe both types serve their intended purposes well. However, if you decide to go the route of a portable generator, then I would encourage you to educate yourself. There are so many resources and experiences online from people who have done this before.

Before we go, I would like to send you off with a warning. While a portable generator may be a cheaper option for you, I would suggest that there are a lot more hazards involved with using one (when compared to a properly installed standby generator). One reason for this is that they are installed by homeowners who are not educated. To me, there are 3 dangers that stick out for the homeowner.

  1. Portable generator may require use of extension cords

I don’t like extension cords for a few reasons:

1. Extension cords can become damaged over time.
2. Many aren’t rated to be used or left outside. They can be damaged by the weather and sunlight, and water can enter the ends of the cord causing corrosion and possible shorting out.
3. Extension cords of the wrong size and length are used all the time. It’s imperative that the proper size and length of wire is used for your application to prevent overheating of the wire.

  2. Grounding

Grounding is a complex topic that requires a knowledge of the Ontario Electrical Safety Code (OESC) and an understanding of electricity. For the sake of being concise, I will keep it simple. It is a code violation and a safety hazard to bond your neutral in 2 locations. It is also a violation and hazard to not have the neutral bonded to the ground at all. There are 2 types of generator neutral bonding options:

1. Generator neutral bonded at generator. This means there is a jumper between the generator neutral wire and the generator metal casing.
2. Generator has a floating neutral. This means there is no jumper installed between the generator neutral wire and the generator metal casing.

With both options, there is a potential for the bonding to be done incorrectly for your situation. If you have a portable generator (with bonded neutral) that powers your entire panel when the power is down, you may be bonding your neutral in 2 locations, because the neutral is also bonded at the main panel. If you have a portable generator with a floating neutral that you just power stuff off extension cords, you will have the neutral bonded in 0 locations. Both situations are hazardous and should be resolved by a qualified person.

  3. Back feeding

This is perhaps the biggest danger of portable generators. I have heard of situations where people (homeowner or electrician) have installed a generator receptacle by the main panel without any safety mechanism to prevent the generator power from back feeding onto the grid. They say they will turn the main breaker panel off and this will prevent any back feeding. What happens when you forget to turn the main breaker off? This presents a massive hazard for the hydro workers, working to restore power to your home. Please don’t think this isn’t a big deal. It is dangerous, illegal, and not the way to provide back-up power to your home.