Unless your generator is 240 volts you aren't going to get 240 volts by tapping two 120v outlets on the generator.
Unless you are lucky.
Just take a multimeter and plug a lead into the hot side on both the outlets. Single phase is single phase and will not be out by 180 degrees. If your two hot leads show 240 volts then you can wire your generator with taking those two hot wires and wiring a new extension cord from those hot leads. On your house panel, they do have 240 volts across the banks of 120V hots. The 180 phase change is from the peak positive voltage of 120V on one line and going thru the neutral (zero) to a negative 120volts on that sine wave gives you a difference of 240v from +120 to -120.
Usually if a generator is wired for 240V, there will be a 240V outlet on it. If they just have multiple 120V outlets, that just means it is a parallel circuit with maybe two separate breakered circuits there.
I would be interested to know the model number of your generator. Some four lead single phase generators are reconnectable for straight 120 volts or 120/240 volts. Some models even have a switch that changes the unit from 120 full power to 120/240 volts. (although that feature is rarely seen these days.)
Good luck with it.
D
On page 10 of the manual at:
http://bsintek.basco.com/BriggsDocumentD...
it specifies that the rated maximum continuous load current is 22.9 amps at 240 volts.
According to the schematic on page 14, you should be able to make the 240 volt, single phase connection between the two similar pins (the ones shown fed by the blue wire and the gray wire) on the round connector at the bottom of the page and run it to your pump, which normally is fed from the two 120 volt bars on your power panel.
For safety's I would consider connecting the frame of your generator to the frame of your pump and connecting that wire to the house ground.
===
While Hoblico is correct in saying that the two 120 outputs are 180 degrees out of phase (relative to neutral), Let's call the phases of the two 120 volt outputs of the generator phase A and phase B.
Then, (where ω 2π*line-frequency) the equation of the sine waves at the outputs are:
Va = Vmax*sin[ωt]
Vb = -Vmax*sin[ωt]
therefore:
Va - Vb = Vmax*sin[ωt] - ( -Vmax*sin[ωt]) = 2*Vmax*sin[ωt]
Note that Vmax is directly proportional to the rated RMS line voltage of your generator.
Hoblico is incorrect when he says that Va - Vb = 0 volts.
The bottom line is that if each of your 120 volt phases is live, the voltage between them will be 240 volts.
You can't feed the 240V pump directly from the generator. Your generator produces a two phase current with 180 degrees between the phases. You need a transformer 120v/240v of appropriate power switched to one of the phases. But first make sure that the generator frequency fits the pump.
If you check the voltage drop between the two contacts of the double breaker in the main panel you get a voltage of 240volts. On my wheel Horse 5500 watt (8500 Surge) generator you get 120 volts on both sides but if you check between the two hots there is nothing. Does this matter when running a 240 volt single phase well pump. I was going to hook the two up to an O-scope that I picked up at a garage sale and I'm sure the two outputs will be 180 degrees out of phase but I know that on many 240 volt applications that don't have any neutral load they are just using the two hot wires for a 240 volt output and as I've said, between the two hot wires on my generator you have no voltage drop. you just have 120 volts between the ground and one of the hots and 120 volts between the ground and the other hot.
Any help would be appreciated. Jay
