Wiring a 2 speed A.O. Smith pump motor

[wack70]

I recently had an A.O. Smith (aka Magnatek) 2 speed pump motor (B984) on my Challenger main pump go bad and replaced it with the same, but newer model (A.O. Smith B2984). I had 4 wires connected to the old motor: 1 green, 1 red, 2 black. The green goes to ground, and based on how it was wired on the old motor, the red went to the L2 terminal (common?) and the blacks went to the L1 (high) and A (low) terminals.

The motor works well, but when I switch from high speed to low speed (using a Compool Cp3600 pool-spa control system), the motor still runs, but it looks & sounds like it is still on high speed. So basically, whether I push the high or low speed button on the control pad, it operates on high speed.

How can I determine if I have the wiring correct? How do I know if the red wire is common, and which of the 2 black wires go to either the L1 or A terminal? I have a meter than I can test voltage with if needed.

Here is a tech drawing of the motor: http://drawings.aosmithmotors.com/Default.aspx?DrawingType=OUTLINE&ItemNumber=B2984

[PoolDoc]

Hi Wack

The drawing you linked does not include a wiring diagram. In any case, you need the wiring diagram that was on or with that motor. I've seen wiring change from motor to motor, even on identical model motors.

So . . . I can't help you, and I don't want anyone else to try either UNLESS they have themselves with their very own hands wired that motor 2-speed operation AND also are 100% sure and have actual knowledge of the fact that all "B2984" units have identical wiring.

Really, the bottom line here is, if you have to ask, you really ought to get someone else to do it.

Sorry.

Ben

[waterbear]

The wiring diagram should be on the motor itself right by the terminal hookups. I recently replaced mine but it is not exactly the same model since mine is a 1.5 HP uprated and I replaced a single speed motor with the two speed motor and then wired the speed selection into my Goldline controller so I had to pull new wires. However, for general info you might want to download from the A.O. Smith Literature Library website (http://www.aosmithmotors.com/literature/landing.aspx?id=42) their #3400, MMU Pump Booklet _Troubleshooting Manual 2006 (first download link on the page) since it does include wiring diagrams (both internal and external) for their pump motors. It is a bit technical so if you don't know how to read them then, as PoolDoc said, get someone to do it for you.

[PoolDoc]

That's a really nice manual, Evan. I'll definitely be saving that one.

[waterbear]

Yes it is. It has saved me more than once when trying to help a customer replace their pump motor.