Size portable generator to run well pump and gas FHW furnace?

[whistlepig]

Bobrip - I think Goose is misinformed as well, however a 1.25 HP is not possible unless you have a sequential soft start special motor/pump ala Grundfos. Submersible pumps are either 1/2, 3/4, 1, or 1.5 HP in MOST residential apps. From 300-1000' the pumps are usually 3 wire, single/three phase 2-5HP with the control box (start caps & controls) above ground.

At 300' down you either have a 1HP or a 1.5HP two or three wire pump. The pump size depends on the static water depth at the driest point in the season at the maximum draw rate or required flow. Our pump is a 2 wire 1.5 HP set at 360', with a high water of 80' and low water in the dry season at 200' drawing 7-8 GPM.

Bottom line is you need a Amprobe meter to balance the load on the generator after you buy/install the one you think you need. It seems the issue is what to buy. With a well in general a 5KW would be minimum and 7-8KW would be optimal for a whole house system.

Whitslepig - thats a nice generator you have!

Thanks for the compliment. We bought our farm from a couple going through a nasty divorce. We got blamed for "stealing their dream farm". The previous owners were uncooperative to say the least. I do know the well pump is 220V but nothing else. I had to size our generator for the worst possible scenario on the well pump. The 6500 watt Honda will power our well pump easily. When the well pump kicks on I can hear the generator power up out of Auto-throttle. It doesn't labor the generator. We power our two fridges, the well pump, pellet stove, TV, and some lights. This is all done via extension cords. A dedicated quick disconnect for the 220V well pump. The dedicated 220V quick disconnect was $200.00 installed by a professional electrician plug and play. Not all that difficult. Not all that expensive after the initial cost of the generator. This is the set up every one around here uses.

 

[TheGoose]

My mistake on the 1.5 HP two-wire pump. Two wire pumps are kind of rare around here and I went to double check the specs online but Franklin's site was down earlier today so I was unable to do so.

There is only one 115V submersible pump made-a 1/2 HP. Everything else without exception is a 230V (there used to be a 1/3 HP but I haven't seen on in years).

Without looking at the specs I believe that a two wire pump uses just a tad bit more power than a 3-wire pump (when used with a run capacitor). There is no capacitor in a two-wire pump, it uses something called a biac switch and split phase wiring. I would explain it but I forgot all the details long ago.....

 

[Carl_NH]

Goose,

See the attached the Gould and Franklin specs in post #35 and you're right the 3wire motors draw a bit lower amperage.

I did pump work in PA for a few years in the 70's and used 3wire over 1/2 HP usually, but it seems regional to the extent here in NH 2 wire are popular today. I suppose its better motors and controls in the 2 wire over time. Personally I would prefer to have a 3 wire and be able to fix things above ground. We do have 4 #10 wires in the well, then 3 #10 feeding from the house to the well head, so didnt feel like diging up and replacing that wire when we replaced it 3 yrs ago as getting water back on was the priority.

 

[TheGoose]

I noticed also that you can get a 115V 3-wire 1/2. Never ever seen one of those, didn't even know they existed. I guess they take a special control box?

In my opinion a two-wire pump is probably just as good as a three wire. I'm not even sure if being able to access the CB gives it any advantage, all the two wires I've come across all seemed to have a long trouble free life.

 

[shortlid]

Was given a Coleman Powermate Maxa 4000 watt generator. It is a 5000 watt surge generator, It has 8 hp Tech. side valve engine. It doe snot have idle control, and has a mechanical gov. But runs good, and price was right.

 

[Gale Hawkins]

I have the 7500 watt 18 HP Coleman. They do not have an idle control (well it is fixed at 3600 RPM) that is 20+ years old. I do need to start it up since it has been a couple years. I try to keep Sea Foam in the the fuel and I kill with with the fuel shut off valve. Our 80' 4" well has a large pump (1 HP I think) and the Coleman will start the pump but it all but kills the lights in the process. The 6.5 China genset will not start the well.

 

[adjusterr]

You would be better off to spend a bit more money and get a Yamaha or Honda generator. I prefer Kawasaki because I have used two of them, one, an 1100 watt for about 25 years and the other, a 2200watt, for about 10 years. Unfortunately, Kawasaki no longer makes generators. Both gensets always start on the first or second pull and are still running with the original sparkplug. Maintenance consists of an annual oil change and filter clean. I just ordered a Yamaha 6600 with electric and recoil start and am installing a genset breakerbox, I'm tired of extension cords. You will find the extra money on purchase will be well spent when you pull the cord or turn the key on some snowy night and the unit fires up. I have determined a few things in my advanced years, one is, you get what you pay for. Good luck. By the way, construction model gensets are noisy as **** and RV gensets generally only put out 110.