This is a generator question

   / This is a generator question #1  

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Dec 15, 2002
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Foster, RI
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Mahindra 3016
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
 
   / This is a generator question #2  
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
 
   / This is a generator question
  • Thread Starter
#4  
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.
 
   / This is a generator question #5  
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.
 
   / This is a generator question #7  
arrow said:
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...
 
   / This is a generator question
  • Thread Starter
#8  
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.
 
   / This is a generator question #10  
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....
 
 
 
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