Question on 3-phase well pump

[Furu]

I have a three phase water pump motor in a well that has not been used for some time. Long story don't ask. When it was put in the well the individual that installed it had a problem in that it was not pumping near the capacity that it should. He made a call to his boss and was told how to fix the issue which it did. I believe he swapped two wires but do not know which ones. The wiring was left "as is" bare end after he disconnected from the 3 phase power and left.

I am getting ready to use the well/pump with 3-phase power. The wiring that comes up from the well is the standard red, black, yellow, green. Interestingly the green wire end is not stripped so he never used it initially, so obviously no ground assuming it is wired normally but I have no reason to believe that the installer wired correctly as he was not the sharpest tool in the shed.

I am not a 3-phase motor expert but my understanding is a 3-phase motor that runs backward can be reversed by switching any two of the three hot wires. (on line research) I do not know this as fact however. Since I am certain he fixed his issue of low pump flow by reversing wires this implies that the well pump was running backward and thus pumping at a low rate. The pump is a relatively high flow pump 50+ gpm.

Will a well pump work, just low flow if running backward? Seems counter-intuitive to me.
Is it true that a 3 phase motor will run backward if wired incorrectly and can be "fixed" by reversing two wires?
Since I am getting ready to wire it up and I have no faith that the wire color coding is to standard I want to figure out what to do if the standard coding doesn't work for running the pump properly.

Hope a well pump installer is on the forum or a motor/pump expert.

[hr3]

Not a well person but I know motors,, Just wire it up color to color and if it dosn't pump well then reverse 2 leads...If is still dosn't pump call a pump guy...

Good luck..

[Willl]

You've got 3 phase power coming in off the street ?

That's pretty rare for a home power supply.

[murphy1244]

You've got 3 phase power coming in off the street ?

That's pretty rare for a home power supply.

I don't get that either, They would charge commercial power rate wich is big bucks. But if you do have 3 phases do what post 2 said.

[Willl]

I'm thinking it's more likely he's got a standard single phase, 220, capacitor start pump where they have the caps in a small box mounted up top and 4 wires going down to the pump motor.

[dex3361]

To answer your question a 3 phase submersible pump will often flow much less GPM when running in reverse depending on the head conditions and the pump. To change the direction of a 3 phase motor just swap any 2 phase leads and try it again. How deep is the well? Are you sure it is 3 phase? As others have stated it is unusual to have a residential 3 phase service.

[Furu]

To answer your question a 3 phase submersible pump will often flow much less GPM when running in reverse depending on the head conditions and the pump. To change the direction of a 3 phase motor just swap any 2 phase leads and try it again. How deep is the well? Are you sure it is 3 phase? As others have stated it is unusual to have a residential 3 phase service.

Thanks for your answer and that of "hr3" both addressed the question that I asked.

From what I found on an internet search I thought that was the case but wanted someone who knew from their own background that was true.

Yes it is a 3-phase motor attached to the pump, no question on that. 300 ft well

No it is not residential and no I have never heard of residential service having 3 phase power under any normal circumstances.

[caver]

We have some pumps at work that will still pump reversed but not as much flow. One set of pumps will spin the impeller off if we get the rotation wrong and don't catch it. Many farms around here have three phase for irrigation pumps.

[Baub]

Here is a good place to ask your question. This fellow seems to know his stuff.
VoyForums: Water Well Helpline Message Board

[podagrower]

If you have Delta 3 phase, you need to be careful which 2 legs you swap. If there are single phase controls, and you put them on the high leg, you will be buying new controls.