Wiring directional switch for 110VAC motor

[beamrider]

I've got an old Rockwell 1/2hp motor here, that I need to wire to run in both directions. It can be a single On-OFF-On switch, or it can be 2 switches, one for power, and one for direction. Wiring diagram states that leads T1, T3, and T5 are connected, and T2, T4, and T8 are connected. Power goes to each bundle, and provides clockwise rotation. To reverse direction, leads T5 and T8 are swapped. I know I'll need a nice chunky switch for the directional part, as arcing is a possible problem, can't really afford an expensive drum switch tho.

I've wired motors like this before, but for the life of me I cannot remember how the hell to do it now. Any suggestions?

 

[sparky5982]

I had a similar problem for a boat hoist. I was able to wire that particular motor forward and backward using a 4-pole double-throw switch.

Something like this worked for that application. The T5 and T8 leads will take one of the poles each to direct the power to one side of the motor or the reverse. The double pole action of the switch will prevent you from back feeding the leads into each other. Make sure you buy a switch large enough to handle the motor. Good luck!

 

[zkling]

Can you post a pic of the motor plate as well as the wiring end?

If you can cut power independently of direction your direction switch wouldn't have to be that large, UNLESS you plan on switching direction while under load, which I wouldn't recommend for that motor. However you need to be careful when doing something like this, as a improper sequence of hitting switches could generate some smoke.

You can usually pick up drum switches for ~$40 on ebay and I think McMaster even has a few pretty cheap. What is your budget range if you don't mine my asking. Electrical is not a place that I would try to save a few bucks.

 

[beamrider]

http://www.flickr.com/photos/86417206@N05/9000606620/

It's the motor I'm using for a bench grinding/honing setup. Direction wouldn't be changed while under rotation, I just need forward to grind, and backwards to hone. Wired up as 110, and not something that's going to be under a serious load, or fired up for more than a few minutes at a time. (Sharpening woodturning tools, for the most part.)

Prices for drum switches must have dropped since last I looked for one, I was thinking more along the lines of >$100 for one. I mean I don't want to have to drop a wad of cash for a switch, any more than I have to, but I don't want to worry about it working when i want it to, either.

 

[zkling]

I would definitaly spring for a drum switch. If you wanted to be fancy with that grinder you could even go with a foot controled reversing switch, but those tend to be pricey.

You should definitaly be able to pick up a drum switch off ebay for <$50 shipped easy. Mcmaster even has one for $40 I think. Most drum switches are rated for 1-2hp, so no worries there.

 

[2oolhound]

I have the same problem. I had a 1hp motor in the 70's that I put one of those 6 connector switches (knife blade lever type) on. Central was off and left turned one way and throw the lever to the right and it reversed direction. Well I visited my bros's farm a while back and it was still mounted to my old bench that I had up there so I brought it home. I blew a motor on my belt grinder so I fitted this motor on and it turns the wrong way and I've lost the diagram. The lever switch I had on it was broken off and just bare wires were there. Can I post pics here or should I start my own thread?

 

[Mickey O]

Any suggestions?

Buy a used drum switch off flea bay.

 

[beamrider]

http://www.grainger.com/Grainger/DAYTON-Drum-Reversing-Switch-2X440

Something along the lines of this, or is a 2x440 more than I really need? Found a few on feebay, tons of cheap chinese ones there that I think I'll avoid.