Military Generators, 1.5 vs 3.0 KW

[Mad_Professor]

Looking at a backup not a primary source.

Seems to be ca. $400 vs $900. and 140 vs 300 ibs. both have 120/220 V

Both gas powered surplus, but rated continuous 1800 rpm , not homeowner.

Any experience/comments?

Note the generation rates above are conservative, more like 2.1 and 4.2, if not high altitude/hot

Want to be able to keep the house happy and be able to run small tools.

Is two small, better than one big? If you do nit need the surge/total?

[randallhilton]

First, figure out how much power you need. 1.5 would run most small tools but 3 might not be big enough for your whole house.

But. . . if you limited your emergency load to necessities only, then 1.5 may be big enough.

The BIG difference would be in fuel usage. If the 1.5 will keep your necessaries running then it would be the better choice. If you need more power, and have a way to split your load into seperate sections, then multiple gennys makes more sense because you can use a low fuel consumption unit when the load is low, then add the second unit when the load is greater.

[nadja]

First, figure out how much power you need. 1.5 would run most small tools but 3 might not be big enough for your whole house.

But. . . if you limited your emergency load to necessities only, then 1.5 may be big enough.

The BIG difference would be in fuel usage. If the 1.5 will keep your necessaries running then it would be the better choice. If you need more power, and have a way to split your load into seperate sections, then multiple gennys makes more sense because you can use a low fuel consumption unit when the load is low, then add the second unit when the load is greater.

I live on solar and use a back up generator for bad weather days. I have 3 actually and my main gennie is my 7kw Kohler which handles my entire houseload very well. My smallest is a 3kw and will not even fire up through my inverter. A 1.5 kw will not even run a decent skill saw, as mine use about 15 amps running and a heck of a lot more start up or surge. Those 1.5 would be lucky if you could get an actual 6-7 amps out of them and doubt if they would handle any surge at all. Especially a refer, even a small one.

[grumble]

Like nadja says, you need to know what the load will be. Nothing worse than needing power for something important, and not having it. If you need power for something like a well pump, two of the smaller gennies won't cut it, you can't hook them together without some way of matching the frequencies. So you should have something able to handle that sort of load.

My experience is different from nadja's in that I have a 3KVA and a 5KVA, and either of them will easily run my house, including the well pump. But the pump is on a different circuit, so the generator runs the pump only, or the house only (reefer, freezer, computer, microwave, NO central heat or air).

But the important thing to know is what the MAXIMUM load you might need will be. Get the generator that fills that need.

[krapgame]

If it were me, I think I'd look at a larger standby generator. My experience concurs with nadja, 1.5 really won't do much and 3 isn't much better. I have a 6.5 portable that will run a refrigerator, 2 deep freezes, my outside wood furnace (pump and blower), an air handler, 3 or 4 CFL bulbs and a small LCD TV easy enough, but not if all are drawing at the same time. For $2300 you can get a new 10Kw (41 amp continuous) LP, air cooled home standby unit delivered that should easily handle most home applications, less central air and electric range. Get the automatic transfer switch wired in and the generator will come on automatically (if you want it to) when it detects a power outage. It uses 1.25 gal/hr at half load, 1.93 at full, so connected to a 500 gal LP tank you'd have between 8 and 13 days of 24 hour per day standby emergency electricity ready to go. With LP being cheaper than gasoline, assuming that both use 1.25 gal/hr, the lp version would run about 33% cheaper to operate, based on current prices locally, plus the LP stores better. The same company has a 7Kw for less than $1800 that'd give you 29 amps continuous. We've got the 65Kw natural gas version at our data center and I wouldn't trade it for anything. We've had it for 8 years now and had no problems. No, I'm not a salesman, just a very satisfied customer.

I guess my point is, for a little more than double the investment you can get a new unit big enough to handle whatever you throw at it. I hate spending money on something only to find out that I didn't get enough capacity to do what I needed then having to spend the same money again plus more later, especially when the difference is so small in the first place.