[How do I?] How do you reverse a non-reversable motor?

[randyjaco]

I have a wood planer that needs a motor, but the motor needs to turn clock wise. I have a 5hp compressor motor that states that it's "non-reversable". Of course it only turns counter clock wise. Yes I know that I could reposition it 180 degrees, but that option is out. Is there an electrical means to get that motor to turn the other way? Or does someone make a make a mechanical device to do the same?
TIA

Randy

 

[f350ca]

You'll need to get into the motor and reverse the ends of either the start or run windings. This changes the polarity of the fields on that initial movement.
Be cautious of a compressor motor rated at 5 hp. Most are way over rated.

Greg

 

[Kernbigo]

i could be wrong but if you remove the armature and reverse it in the winding it may work

 

[Mikelkie]

Non reverseable motor or compressor head? 5 hp motors must have a capacitor start arrangment with a centrifugal switch.
Most times the "non reverseable" motors are called so because the the windings are permanently connected
inside, laced up and varnished over, by carefully undoing this it can be separated at the risk of irreparable damage.
It's unlikely that a 5hp motor is non reverseable, a pic of the data plate will help.
Kernbigo's suggestion to reverse the rotor will work providing the rotor runs correctly in the stator and not
overshoot the windings one end

 

[BillWood]

Is there a way of doing this with a couple of gears ? Build a small gearbox ?

 

[randyjaco]

Gears were the first thing that came to mind. But @5hp at 3400 rpm is bound to get hot and need a lot of lube. I would also think that the friction losses would be high.
Here are some pictures of the face plate

 

[Technical Ted]

Can you twist the belt? If there is a belt involved, twisting it 180 degrees (into a figure 8) will reverse direction of the driven device. You may have to buy a little longer belt.

Ted

 

[Dabbler]

not worth the trouble to try. you will only damage the motor. Use it for something else, and get the right motor.

why do I say this? well if you look closely at a non-reversable squirrel cage motor, the armiture laminations have a 'set' to them. by reversing the windings and with a lot of trouble, you can make about a 1 1/2 horse motor that will spend the rest of the current heating the windings. been there. made it work. never again.

 

[talvare]

i could be wrong but if you remove the armature and reverse it in the winding it may work

You're not wrong. This will work, but it's important to make sure that the rotor bars align with the stator bars. It won't work with all motors, but I have been successful several times

Ted

 

[randyjaco]

Thanks very much guys. I am going to give reversing the rotor a try. If it doesn't work, it's no big loss. But it is such a great hack, that I have to try it.
Figure eighting the belt might work, but I will be running 2 belts with a max distance of 24" between centers. I am afraid that they would rub. But I might be able to cock the motor off center a few degrees.
This is one reason this site is so great. Plenty of ideas that I might not have come up with myself.
Randy