electrical question: backup power source
Okay...not really a cabin or backcountry living question...but one relating to my Anchorage home. I know we have a few "sparky" folks on here...
My electical is set-up to isolate and run my heating system (gas-fired boiler and indirect hot water heater -- all 110V) off a backup power source in the event of an extended electical outage. Last week's mat-su windstorm got me to thinking that I've never tested this since we bought the place, or since I had a new boiler installed last fall.
I have an old, clunky generator which is a PITA to start, and noisy as heck, so I'm in the market for a new one. I've got my eyes on a Honda...probably the EU2000...but I want to make sure this has enough juice (or even if I can get away with the 1000 watt model).
So, I'm in the process of trying to figure out what the power needs are, in order to pick the right generator. Is this as simple as adding up the max draw for each component in the circuit (boiler, 2 circ pumps, zone valves...) or am I missing something? Are there any other things I need to be aware of?
Yes it is kind of like your discription, you add up the needed amps, remembering to start a motor it is normally 1.15 times inrush. so If everthing is going and you start the largest motor you have to have enough to get it rolling. I just went big and put in a 15,000 watt 50 amp. Honda Diesel Gen set, it works great. Make sure if you hook it up to your grid system to isolate it completly from the poles, including the neutral (white wire). Watts are amps multiplied by the volts. for example at 120 volt, home power, 1 ampX volts equals 120 watts. When you buy a gen set the 2000 refers to the watts available. So just do the math and see if you have enough "juice". Have fun.
The EU 2000 is a good generator but without knowing your system you should take a look at this chart
The bummer about these 2000 is like was mentioned cant run a compressor for a nail gun and a worm drive starts real slow with them, not good for the tools. Its good to have extra surge capacity when it comes to generators and electrical motors. The brushes in the motors don't like a lack of power. Hope it helps
thanks fb and gerberman. I'm waiting for info back from the manufacturer about the electical specs for the boiler itself. It's a high-efficiency model and I think I might be able to get away with the 2000 watt generator. I've got the specs for the grundfos pumps already. Maybe I'll post it all here for someone to double-check my math when all is said and done. I just hate to buy a gen to find out it ain't enough.
i really think you should upsize, even if specs suggest you can get away with it. momentary draw when a motor first kicks is often larger than its rating.
say you want to plug your freezer in on day 3 of an outage, and then the boiler goes to kick on...
or the boiler is running, and the freezer compressor goes to kick on...
just not worth it. you want a safety cushion, i promise.
those honda generators are designed for remote needs where weight/space is an issue and you only need a little bit of power. For a permanent at home application especially powering (multiple) large appliances, they just are not the right tool for the job.