This is a generator question

[arrow]

Since I am not sure where to post this and since I am considering a 7800 watt pto generator as an attachment, this may be a logical place for my question. I've been reading a bunch of old generaor posts and can't seem to find an answer there. My well point cover states I have a 1and 1/2 hp submersible pump @ 115 volts and rated 2 hp @ 240 volts. I am assuming that because there is a double 15 amp breaker for the pump that it is pulling a 240 load. The local well guy states that I need a 6000 watt generator for just the well alone. The pump is 360 feet down with a 75' outside throw to the house. the generator will be placed another 80 feet from the service box. Since I know little about this stuff, it is wiser for me to get some answers from people in the know. Does this seem a feasible generator for this application. Thank you

 

[lovemytoys]

i just checked my well and the pump only draw max 7 amp per phase.i have a 6500 watt gen and the load max is 38 amp so im good to g

 

[tomd999]

Hiya,

Easy to use converter: Power Calculators for quick conversions.

Tom

 

[arrow]

Thanks guys. This is where I'm not good. I looked at a bunch of supposed ratings and thought all I needed was a 4000 watt generator for the well. I was told I am not in the real world and would need at least 6000 watts for my application. I get lost with amps and volts and such so I just need to listen to some "real world" scenarios that kind of match my needs.

 

[atgreene]

FWIW, I have a 16 kw pto generator that powers my entire house and garage. My well pump is a 3/4 horse 220v set at 450'. When it kicks on and the a/c's are running the 'puter auto shuts down due to the sudden drop in voltage.

If I run just the well and a few lights I have no issues. The biggest thing to get right is the hertz, as I learned here. I bought the hertz meter from that company in NC? and used it for the first time last week for a 12 hour outage. Worked wonders.

7800 kw isn't a lot when running pumps and such, but I suspect if you run a heavy enough line and set it up properly with limited other draws, it should work. Depends upon if the generator is 7800 continueous or 7800 at a sudden spike.

My 16 kw runs on my 4150 Kubota (40 hp pto +-) pretty well. I suspect a smaller tractor could run it, so you may want to look bigger. I bought mine for $1600 5 years ago.

Good luck.

 

[lovemytoys]

my 2 cent get the bigest gen that you could afford

 

[RonMar]

Since I am not sure where to post this and since I am considering a 7800 watt pto generator as an attachment, this may be a logical place for my question. I've been reading a bunch of old generaor posts and can't seem to find an answer there. My well point cover states I have a 1and 1/2 hp submersible pump @ 115 volts and rated 2 hp @ 240 volts. I am assuming that because there is a double 15 amp breaker for the pump that it is pulling a 240 load. The local well guy states that I need a 6000 watt generator for just the well alone. The pump is 360 feet down with a 75' outside throw to the house. the generator will be placed another 80 feet from the service box. Since I know little about this stuff, it is wiser for me to get some answers from people in the know. Does this seem a feasible generator for this application. Thank you

It should work, Power in Watts(P) = Current(I) X Voltage(E) 7800W divided by 240V = 32.5A of current. 7800W Divided by 120V = 65A of current, with that 65A divided equally between the two 120V legs(32.5A per leg). If like most generators it is a split 240 affair like the power that feeds most US hoseholds, a single 240V circuit(hot wire to hot wire) comprised of two 120V circuits(each hot wire to neutral). So each 120V circuit on that generator probably has a 30A circuit breaker on it. Based on your statement that the current wellpump circuit has a ganged 15A circuit breaker(15A on each leg), it should work.

Some more information about the pump would be helpfull such as rated current draw for that pump, startup current draw, and full load/pressure current draw. The best info would be to measure these current draws in operation, but it sounds as if you don't have the tools or training to do this. If you can get the rated current information from the manufacturer, an educated guess can be made at the other numbers. Are you planning on this genny just for the pump, or do you have other loads for it to power? How large a tractor are you going to hang it on(how much PTO HP)? You need 2 HP per KW of generator load, so that 7.8KW generator needs at least 15 PTO HP...

 

[arrow]

My pto hp is 17. The draw on the pump is a mystery as I do not know who manufactures the pump. I do not plan to run but one or maybe 2 items together such as the furnace. Was told because of my wire runs, I would need 6000 watts just for the pump which seemed excessive to me but I am next to clueless as far as the intricacies of electricity and only informed by what I've read which seems is not a good enough knowledge base.

 

[Rara Avis]

Tractor-Driven Generators: Producing Quality Power

 

[Skyco]

The start up current is the killer on motors- while it may run on X amps it can be 2X or 3X or even more to start the darn thing....

 

[FLHayman]

Since your well is run off 2 15 amp breakers, and assuming they are not heating up with normal use, you could go as low as a 3600watt generator IF you cut off the breakers supplying the fridges and lights, etc, then charge up the tank.

Your idea of the 7K+ generator seems realistic, since nobody would want to constantly turn off everything to charge up the well tank. Just be aware that microwaving something at the same time the well pump starts could give you a brownout. No big deal if the wires, plugs and connections are all good, but electronic stuff doesn't particularly like it. UPS your computer or use your laptop, and watch the cheapest TV!

I've seen lots of small generators overstate their real world capacity, so it would be good to subtract about 25% of capacity for average use. Your tractor should do a better job of handling the load of a starting current drag on your generator, since it would have more torque than a homeowner generator with a briggs and stratton engine.

I'm also interested in PTO generators to upgrade my place, but have thought about running in 1000 RPM mode, with the throttle way back, in order to get 540 rpm. What I would lose in sudden torque or peak hp would be a good tradeoff in a larger tractor for better economy during the relatively low load times between electric motors for the appliances.

Try using a 'Kill a watt" meter for your 110 appliances, available even at China...I mean Harbor Freight. I used one to help evaluate things for solar power. On a generator, air conditioner and hot water is pretty much out, unless you have a pretty large one!

 

[mkulikow]

As mentioned the start up current is a killer but a 7kw generator should power most well pumps if NOTHING else is connected to that circuit unless the well pump is off. Most people run the pump to pressurize the system, turn it off and then use other appliances. Both the pump and other appliances will spell disaster for a 7kw generator.

There is a big difference between "turning" a motor and "powering" it.

You are ALWAYS better off having more power than you will ever need when it comes to generators, unfortunately for most that means that PTO generator is nowhere near enough.

And "brownouts" will do fatal damage to motors in every sense of the word, you just won't realize it for awhile. Again, the statement above about powering a motor and turning it should be committed to memory.

 

[atgreene]

I'm also interested in PTO generators to upgrade my place, but have thought about running in 1000 RPM mode, with the throttle way back, in order to get 540 rpm. What I would lose in sudden torque or peak hp would be a good tradeoff in a larger tractor for better economy during the relatively low load times between electric motors for the appliances.

FWIW, I tried this with mine, although in 750 rpm mode. It doesn't seem to do well, as the tractor govenor isn't capable of keeping it that close to the set rpm's to keep hertz constant. At 540 the flywheel effect of the engine does much better when the govenor kicks in. On 750 the hertz drop while under a real heavy load. Ok for lights and such, but as you stated, electronics don't like it.

 

[tommu56]

Arrow
Is the generator for back up to the grid?

If you are off grid I would suggest a groundfos sqflex pump I have one off grid at my cabin and it runs on a 2800 watt inverter with out any problem with the pump, I do have a slow well and at 450' so I pump 2 or 3 times a day for about 20 minuets each

tommu