Thursday, July 26, 2012
Portable & Standby Generators
To guard against carbon monoxide poisoning, you must run a portable generator outside and well away from windows and doors. Running it in the garage is also out because the exhaust can work its way inside even if the big door is open. And don’t even think of modifying an extension cord so you can plug the generator into a house outlet. Generator power needs to bypass the house wiring completely (by running extension cords directly to appliances) or go through a transfer switch, which also acts as a one-way gatekeeper that prevents the current from energizing your home’s transmission line and shocking an electrician working to restore power to your neighborhood.
But the convenience of automatic standby power comes at a price: Installed units often come to about $10,000, though you can shave off a few thousand dollars by going with a small unit that powers just a few circuits.
In general, a 5,000-watt portable generator is the minimum that’s worth getting to back up vital systems. That’s enough for a fridge, a few lights and even a room air conditioner. Built-in systems start about 7,000 watts, but to keep central AC running, you’ll probably need 17,000 watts to 20,000 watts. Above that, the price jumps because higher-power generators need liquid coolant, not air.
(Wash Post, 7/18/2012)