Emerson Electric Motor - info needed

[Perplexed]

I recently acquired an Emerson 1/30 hp electric motor that came with four wires coming out of the housing, with the exposed ends of each pair twisted together. The seller didn’t know anything about it other than to say it worked when power was applied. I labeled the four wires 1-4; 1 and 2 were joined, and 3 and 4 were joined. 2 & 4 are thicker than 1 & 3. I tested for resistance between them all, after undoing the twisted pairs into four separate wires, with the following results:

1 - 2 = nothing
1 - 3 = 28.0 ohms
1 - 4 = nothing
2 - 3 = nothing
2 - 4 = 16.5 ohms
3 - 4 = 44.3 ohms

I also tested the motor with the two twisted pairs 1-2 and 3-4 by applying 110VAC, and the motor ran smoothly for the few seconds I tried it. I’ve tried researching this motor online with no luck, so I’m hoping you electrical wizards can help out. I’m given to understand that if I switch the four wires 1-4 and 2-3, the motor will run in the opposite direction, but I haven’t tried this yet. I’ve attached a picture; I’d like to know more about this motor since I’ve never worked with one that had four wires coming out of it. What would a typical wiring diagram look like? Do I need a run capacitor or a choke - how would I determine this? How would a switch work to reverse the direction of the motor, since a double pole double throw switch works with two different pairs of wires that are not changed up? Thanks in advance!

 

[Letfreedomring]

Subscribing for future knowledge...

 

[KOPBET]

Without some wire identification it's going to be a bit tough. Do you not have any ID for the wires? Inside one of the covers maybe?

The higher resistance winding is probably going to be the field winding, and the lower resistance would be the armature winding. There are a number of wiring diagrams on the web for 4 wire motors that should help get you started, including how to reverse direction of the rotation.

 

[Perplexed]

Without some wire identification it's going to be a bit tough. Do you not have any ID for the wires? Inside one of the covers maybe?

The higher resistance winding is probably going to be the field winding, and the lower resistance would be the armature winding. There are a number of wiring diagrams on the web for 4 wire motors that should help get you started, including how to reverse direction of the rotation.

Thanks for the tips. I did find a bunch of 4-wire diagrams online, but they really didn’t help with identifying which wire was which. I’ll try looking inside the covers when I get a chance, and trace each wire as close to its source as possible.

 

[Perplexed]

The plot thickens - I removed the end cap where the wires came out, and revealed an interesting arrangement. The end cap has a pair of copper strips with Wire #3 soldered to one, and another wire soldered to the other strip leads to the exposed windings on the end of the stator. Wire #1 also goes to these exposed windings, and #2 and #4 appear to go to the wrapped windings, like on a desktop fan. Then there’s what looks like a centrifugal switch on the shaft of the rotor, and this is a first for me. The switch has a flat copper ring that appears to be in contact with the two copper strips when the end cap is installed. I moved the two spring-loaded arms of the centrifugal switch outward, and the copper ring was lowered on the shaft. This suggests to me that the exposed windings are a start winding, and once the motor is running, the centrifugal switch disconnects power to this start winding. Correct?

I also tried switching the paired wires 1-2 and 3-4 to 1-4 and 2-3 and applied power, and the motor ran in the opposite direction (CCW).

So this looks like it could be a reversible motor, which means I need to figure out a switch that would shift the pairings and also apply power. The DPDT switches I’ve seen don’t do any pair shifting - they merely apply power to one fixed pair of wires or the other. Is there a switch that would accomplish this pair shifting - or is the motor meant really to go only in one direction?

 

[Mr.Glock]

It can run clockwise and counter clockwise.

 

[dennishoddy]

The plot thickens - I removed the end cap where the wires came out, and revealed an interesting arrangement. The end cap has a pair of copper strips with Wire #3 soldered to one, and another wire soldered to the other strip leads to the exposed windings on the end of the stator. Wire #1 also goes to these exposed windings, and #2 and #4 appear to go to the wrapped windings, like on a desktop fan. Then there’s what looks like a centrifugal switch on the shaft of the rotor, and this is a first for me. The switch has a flat copper ring that appears to be in contact with the two copper strips when the end cap is installed. I moved the two spring-loaded arms of the centrifugal switch outward, and the copper ring was lowered on the shaft. This suggests to me that the exposed windings are a start winding, and once the motor is running, the centrifugal switch disconnects power to this start winding. Correct?

I also tried switching the paired wires 1-2 and 3-4 to 1-4 and 2-3 and applied power, and the motor ran in the opposite direction (CCW).

So this looks like it could be a reversible motor, which means I need to figure out a switch that would shift the pairings and also apply power. The DPDT switches I’ve seen don’t do any pair shifting - they merely apply power to one fixed pair of wires or the other. Is there a switch that would accomplish this pair shifting - or is the motor meant really to go only in one direction?


View attachment 308341

Use this drum switch. It's cheap and totally reliable. I use them on two different lathes to start the chuck in forward or reverse. You can also bump it in the opposite direction as a crude brake.
https://www.amazon.com/1-5-Electric...mzn1.fos.006c50ae-5d4c-4777-9bc0-4513d670b6bcEdit: the drum switch I posted a link to is a spring return to center or off position, momentary contact. There are models that latch in either direction and spring return to off.

 

[2busy]

Can't see much on my ph