Seems to confirm a Universal, (series) connected motor, you do not see shunt field connected motors on AC .

I have a VS drive that has a very simple DC shunt field supply. Made by GE. So there are shunt wound VS drives and motors, It does use an SCR to vary the motor speed. So it is a DC shunt motor running on slightly filtered rectified AC.

 

So it is in fact Not an AC shunt field motor!

 

I have come across series motors that were run on DC, in AC powered equipment. More torque that way. And with the diodes , no telling. Could easily be a DC universal motor with a few diodes.

 

I have come across series motors that were run on DC, in AC powered equipment. More torque that way. And with the diodes , no telling. Could easily be a DC universal motor with a few diodes.

YES, series field (Universal/AC/DC) motors, I was specifically referencing shunt field versions.
Re: Your post #21. !

 

I have come across series motors that were run on DC, in AC powered equipment. More torque that way. And with the diodes , no telling. Could easily be a DC universal motor with a few diodes.

The word "universal" refers to a motor which can run on AC or DC. So "DC universal motor" isn't really "a thing."

 

The word "universal" refers to a motor which can run on AC or DC. So "DC universal motor" isn't really "a thing."

What I have come across is an item with a universal motor that includes a circuit board with rectifier or rectifiers, and often a filter cap. So the motor is being fed DC with some degree of filtering. Not sure just why, but there must be some reason because it does add to the cost. So there must be some benefit.

 

What I have come across is an item with a universal motor that includes a circuit board with rectifier or rectifiers, and often a filter cap. So the motor is being fed DC with some degree of filtering. Not sure just why, but there must be some reason because it does add to the cost. So there must be some benefit.

I have not seen this but I'll take your word for it. It could be for EMI reduction. Mechanical brush commutation is pretty electrically noisy. In exceptionally noisy applications it may prove to be necessary to decouple the motor from mains via a rectifier and capacitor to meet FCC or UL criteria. This is just wild speculation on my part but seems plausible.

 

I went back and traced part way thru the wiring diagram and the one relay does seem to reverse the field series connection to the armature. I have not discovered what the other relay does yet, although it is probably a run/stop control function.
I also see that the TS was asking about the motor connections. My guess is that the wires presumed to go to the missing starter switch go to the brake coil. And we can see that the brake has a bridge rectifier, I am guessing that the motor also runs on DC as well. And then it is short circuited for quick stopping, because hoists need to stop quickly.

 

Good day everyone,

I have a very old 120v AC motor which came our of a winch. Motor has 4 wires and attached diagram. Could someone help me understand what this diagram says?
I did not take the motor housing apart but I am guessing it has centrifugal switch(??)
View attachment 288439



Thank you very much!

It may not be an AC motor, likely to be a Universal Motor with option to change the rotation direction as required in a winch.

 

One more question relates to the brake. If the motor turns freely with nothing connected then the brake is "energize to brake", and you can ignore the brake connections unless you need the braking function. If the motor does not spin free then the brake is "energize to release" and you need to power it to allow the motor to rotate. In that case you will need a bridge rectifier to provide dc TO THE BRAKE. From the circuit diagram in post 7 I see that the brake operated from rectified mains voltage. And also from that diagram it seems that the motor is a series wound universal type motor. This means armature and field are in series, but with some items in series with them, across the mains. So you need to go into the manual and let us know what the parts list calls those items, 53, 55, and 56 that we see on the drawing. It might be a 90 volt DC motor, or something else weird voltage motor.

 

post #6

From the circuit diagram in post 7.
So you need to go into the manual and let us know what the parts list calls those items, 53, 55, and 56 that we see on the drawing. It might be a 90 volt DC motor, or something else weird voltage motor.

You mean post #6?
Also the OP has listed the items 54, 55, 56 in the post #11
Item 53 is a 115v to 24v transformer.
Practically all the (mains operated) N.A. Treadmill motors I have come across are rated 90vdc.

 

Thank you everyone who helped with solving this. Here is the summary:

The motor is universal and connection was exactly as it was advised earlier.

DC circuit is not utilized because the winch did not have a break. The break is achieved simply by the large gear ratio.

Transformer is used solely to operate a relay @30vac and provide low voltage to the switch. The two relays were not needed in my case because I need it to turn only single direction.

I wish I would have reduced the disconnect arc seen on the relay. I suppose it's not a big deal since the relay is rated for double the amperage. Perhaps if this becomes a problem i will get a solid state relay.

Thanks again

 

I wish I would have reduced the disconnect arc seen on the relay.

A snubber across the contact may help with that.

 

A snubber across the contact may help with that.

Yes. I found formula online to calculate RC sizing but I don't have enough knowledge of electronics to understand it.

 

Usually a 0.2μF in series with 100Ω
https://forum.allaboutcircuits.com/attachments/snubbers-pdf.179378/

 

So what are the two extra wires mentioned in one post?? The motor does not have a starter switch.
And, as it was used on a winch, possibly as a hoist, probably it would be an intermittent duty motor, not suitable for blower or lathe applications.

 

So what are the two extra wires mentioned in one post?? The motor does not have a starter switch.
And, as it was used on a winch, possibly as a hoist, probably it would be an intermittent duty motor, not suitable for blower or lathe applications.

Sorry which two extra wires? It's been a while please remind me.

Yes it was a winch on a hoist and, you right, I'm not going to be able to use it for anything other than that but I learned a lot in the process.

 

Now I can not find the mention of two extra wires. Oh Well.

 

Really, an intermitant duty motor has a lot of possible uses that do not demand constant operation. and if it is run at less than full load it might handle a longer duty cycle. It wll depends on heating.