Help to connect reversing switch to a motor

According to Alex :

One of those wires is probably the safety ground. It should be either plain green (if old) or green with a yellow strip (for a newer motor). I presume that the motor nameplate says that it is capable of operation at either 115 VAC or 230 VAC. If so, the six wires should be:

(1)-----WWWWWWWWWW------------(2) 1st run winding

(3)-----WWWWWWWWWW------------(4) 2nd run winding

(5)-----WWWWWWWWWW---)|-o->o--(6) start winding with cap and centrifugal switch

(Warning -- the numbers are for my convenience, and are likely to not match any on the motor in question. See the maker's label or information under the wire access cover.)

Now -- for running at 115 VAC, you want the following connections for forward:

(L1) -- (1) -- (3) -- (5)

(N) --- (2) -- (4) -- (6)

To reverse it, interchange (5) and (6) in the above connections.

For -- running at 230 VAC, want the following connections for forward:

(L1) -- (1)

(2) --- (3) -- (5)

(L2) -- (4)

with (6) also connected to (L1) for one direction, and to (L2) for the other.

Beware that the changing of the connections of (6) (and perhaps (5) for 115 VAC) while the motor is spinning will not reverse it until it has slowed down to a stop and then been switched back on.

Now -- your problem is that your switch does not have enough poles to handle both reversing and start/stop functions on a motor like this. You need a third pole to interrupt power to both sides while stopping the motor, so there is no part of the winding powered when the motor is stopped -- so you are less likely to get a shock form the motor if water gets into it while it is stopped.

A "drum" switch has the needed contacts to reverse everything and to stop the motor safely.

For your 115V operation, you could switch the motor so it would reverse with your switch, but you would need another switch to handle the start/stop function.

Go up to the section for 115V operation, and connect the center two terminals of the switch to (3) and (4) in place of the wires from (5) and (6).

Then connect the opposite corners of the switch terminals in an 'X' shape, and connect one side of the 'X' to (5), and the other to (6). You will still need another switch between (L1) and (1) to turn off the motor. And -- you have another problem -- that center "stop" position is wrong for the motor, because it can allow you to switch on the motor (with the other switch) while the start winding is disconnected, which will cause the motor to hum loudly, and if left switched on, it will burn up.

If you were running the motor from 230V (which might be a better choice anyway, if it is 1HP or larger, as it will draw less current and be less likely to trip the circuit breaker), you can wire the switch to start/stop the motor and to reverse it -- but for safety, you will want to unplug the motor when not using it, since one side will stay live.

Let's go back to my drawing for 230 VAC operation, and set up the switch as follows (the terminals are):

(A) (B) (C)

(D) (E) (F)

O.K. First -- connect a wire between (A) and (C)

Connect (L1) to (B).

Connect (A) or (C) to (1) (it doesn't matter which, since they are connected together anyway.) (1) is already connected to (L1)

Connect (D) to (A)

Connect (F) to (4) (which is already connected to (L2).

Now -- you should have the motor stop when the switch is in the center position, and it should run in one direction with the toggle is thrown to one side, and it should run in the other direction when the toggle is thrown to the other side. And the enforced pause in the stop position will keep you from switching on through and keeping running in the wrong direction.

But -- a drum switch will be safer. It is 3PDT -- and often has the 'X' crossover already in place.

Good Luck, DoN.

DoN,

this is a great description! Now everything is clear. Including the fact that I bought a wrong switch - it has no start/stop function :)

Thanks, Alex

D> According to Alex :