Pellet Stove Generator Backup

Pellet stove generator backup may seem the obvious way to go to protect yourself against power outages, and continue to run TV's, the fridge and freezer and a few lights - an obvious advantage over battery backup. Until, that is, you remember that pellet stoves are run by little computers.

The circuit board in a pellet stove is effectively a small dedicated computer, and one thing that computers do not like is a 'dirty' power supply.

Other types of appliance don't like dirty power either. Electric motors - you'll find three in the average pellet stove - auger, combustion fan and convection fan.

Electric motors can be heard to struggle, not put out as much power as usual, and can actually have their life shortened by using them with an unsuitable power supply.

Other household appliances that play up are fluorescent lights and room fans, (buzzing). Televisions can show a line rolling down the screen. Microwaves often buzz and don't cook normally.

What is "Dirty Power?"

How to explain this without getting technical? Utility companies supply your household with alternating current (AC). It's called alternating current because it cycles smoothly between positive and negative voltage (pure sine wave - imagine a smoothly rolling ocean).

Some generators put out a 'modified sine wave' In the worst case, imagine the waves on that ocean as being made up of slab sided high and low concrete blocks, and you'll get the idea.

The closer a generator's output is to a pure, smooth sine wave the better.

Choosing A Generator"

You pretty well know what to look for by now, but here are a few more tips.

In the generator specifications, as well as 'pure sine wave', look at the figure for Total Harmonic Distortion (THD) which is the distortion of the sine wave. A figure of 5% or less should be fine.

Voltage regulation (RMS) which if poorly controlled can cause lights to dim and brighten should be around 5%. Peak voltage regulation is good at about 10%.

What size generator should you get? Add up the wattage of all the appliances you want to use in a power outage situation. The information will be on the back of each appliance. Don't forget the fridge and the freezer.

Remember that appliances using electric motors will generate a power surge on start up, and that a pellet stove ignitor will demand more power on start up, so to be safe, double the calculated wattage when choosing a generator. If power consumption is given in amps, multiply amps by the mains voltage to get watts.

Already Have a Generator?

Already have a generator, but it's not up to spec? There are remedies.

A 'power line conditioner' can clean up 'dirty' power supply. You just plug the generator in on one side, and the appliances on the other. Look for one that's rated above the wattage of the appliances you want to use with it.

Output from the generator can be used to charge a battery connected to a pure sine wave inverter. Some pure sine wave inverters can be connected to the utility supply to charge a battery. This is similar to battery backup but with sockets for other appliances.

If a power outage occurs, the inverter can automatically kick in. They tend not to be as powerful as power line conditioners.

How To Connect Your Generator

If you just want the generator to feed the pellet stove, simply connect it directly.

The simplest method to connect the whole house is known as 'back-feeding'. Just plug the generator supply into an outlet socket on your ring main. Make sure to switch off the utility supply at the fuse box first. THIS METHOD IS ILLEGAL AND NOT RECOMMENDED.

The traditional way to wire your generator into your home is by using a 'Transfer Switch Kit' which can be inspected and certified.

Cheaper than a 'Transfer Switch Kit' is a 'Generator Interlock Kit' which you can also have inspected and certified. Here's more information from Generlink.con