Sizing emergency power generators

The right “size” emergency power generators provide just enough wattage to operate all your essential equipment. Too few watts and you can overwork the generator, potentially damaging it and anything plugged into it. Too many and you’ll waste money on the initial purchase and on the fuel to run it.

The most reliable way to assess the size of an emergency power generator you need is to use an ammeter, a device that measures electrical current. With an ammeter, a qualified electrician can determine exactly how much power your business needs. Some electrical generator dealers will visit your location and do this as part of the sales process.

Be aware that any electronic appliance with significant moving parts – fans, pumps, compressors on refrigerators or air conditioners – can require up to three times as much power to start up than it does to run continuously. Make sure this startup power requirement is factored in to your measurements.

Don’t estimate. Rules of thumb based on the size of your business are never a good substitute for actual investigation of the devices your emergency power generators will work with.

What size emergency power generator to buy
Once you’ve factored in your startup requirements, you’ll have an idea how many watts you need from your emergency power generators. To avoid overworking your generator, you should plan on purchasing one with a rated capacity of around 20% more than your exact requirements. This will give you room to add a few small devices, in addition to helping extend the lifespan of the power generator.