GE pump motor wiring help

[wesst]

I have an irrigation pump that uses a Meyers QP-15 pump head driven by a GE (possibly vintage) 5KC 48PG 662T electric motor. The motor is rated for 230/115 and is currently wired for the higher voltage. This pump will be used to pump lake water for the irrigation system.

I would like to rewire it to run at the lower voltage since my lake pump house has 120vac. The question I have is what wires do I switch? The access cover plate used to have a schematic on it, but is not longer there.

Under the plate are four vertical connection posts. The incoming power is connected to number one and number four posts. The only two remaining wires are piggybacked onto the third post. Nothing is on the second post.

Now I have made up the numbering system with the top post being one, and the bottom being four. There are actually no markings whatsoever on the pump nor are there any near the posts. I believe the windings are wired in parallel and I would like to wire on series.(or vice versa).

Anyone familiar with these pumps? I thank you all in advance for your assistance.

 

[American Locomotive]

Post a picture. I suspect this motor has a simple configuration, where there are two independent main windings. You put them in serial for 230v operation, and in parallel for 120v operation. Your current configuration makes sense for the pump being wired for 240v operation, as they're just using that 2nd post as a convenient wiring point to serialize the two windings.

Putting it back to 120v operation is likely just as sample as taking one wire from the 2nd post and moving it to post 1, and taking the other wire from post 2 and putting it on post 4.

There are two "gotchas" with this though:
1) If you inadvertently put both wires from the same winding on the same mains post, the motor will not turn on at all. Just keep track of the wires - you know each winding has at least one wire already connected to mains, so you really only have to worry about the two wires.

2) Hooking the two windings "anti-parallel". You can imagine each winding in the motor having a certain orientation inside the motor, which are aligned. When hooked in parallel, the windings will be energized such that each winding has the same magnetic polarity at a given moment, ex. the "top" of both windings will both be magnetic "North" before flipping to "South" from the AC power.

Anti-Parallel is hooking both windings in parallel, but accidentally swapping around wires of one of the windings. What will happen is one winding will be "North", while the other winding will be "South". The windings of the motor will then fight each other.

But, I believe as long as you leave whichever wires that are connected to posts 1 and 4 where they are, you will not have a problem.