Power out, Generator on.

[BobRip]

What kind of pump do you have? Unless you have a 3" submersible, it should only take a few seconds for your pump to get up to normal operating speed, if not sooner.

The 3" pumps are different because they spin at a much higher RPM and have to wind up. I'm guessing that is what you have since I'm not aware of any 4" pumps with 1.25 HP ratings.

For the 1/2HP you can get by with a relatively small generator.

I have a 3" submersible. The current is in 3 steps (let's see if I can remember). It's real high for the first 4 or so seconds. Then it drops to about twice rated current until 30 seconds have elapsed. Then it goes to about rated current. My theory is that the pump must accelerate a 400 foot slug of water (300 feet down the well, and about 100 to the house). Once this is moving the current drops to rated current. By the way this means over 400 feet of wire between the breaker and the pump. I am sure this is a factor. We originally had 12 gauge down the well, but replaced it with 10 gauge after hurricane Isabel. It does start better and the charts show that with 12 gauge we were right at the edge of needing bigger wire.

 

[dave1949]

I have been told that not all generators are created equal. If you connect them to a known test load, some will not produce their rated capacity. Don't know how true that is, but something to think about.
Dave.

 

[bc realtor]

Hello mousefeild
for some local knowledge ask Doug the head of electrical at home depot in Nanaimo. he can help as he is very good at answering these exact questions. He is a industrial electrician:thumbsup: he has set me up quite well for the generator and the bypass switches to be legal.