# Help with drum switch



## Dsjm2005 (Aug 2, 2021)

I need some advise on what is going on with my motor and drum switch.  I have a 1/2 hp split phase reversing motor that I have wired to a Furnas drum switch on my little SB 9c.  I have it wired as in the diagram and it will run forward and reverse as it is supposed to.  However when it runs for a little bit the motor smells like it is getting hot and the case of the motor gets hot.  I can disconnect the motor from the drum switch and connect power directly to the motor and it seems to run fine without getting hot.  This obviously tells me something is going on with my wiring.  

The motor has two spade terminals and indicates to reverse the direction of the motor to just switch the two spade terminals.  I have attached a diagram of how I currently have it wired.  I am trying to wire it as per the diagram in the upper right hand corner schematic.  Any ideas would be greatly appreciated.


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## markba633csi (Aug 2, 2021)

It sounds as if the start winding is not being cut out as it should be when the motor is up to speed- the motor's internal centrifugal switch is being shorted out when you wire in the drum switch.  That would explain the overheating.
Can you post more info on the motor itself?  A close up would be helpful, of the data plate or label
Also, do you have a multimeter of some kind?  We might need to do a couple simple tests
-Mark


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## Dsjm2005 (Aug 3, 2021)

Thanks for offering to help Mark.  I do have a multimeter I can grab this evening.  Here is the pic of the nameplate on the motor. Not sure why it places it upside down.


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## markba633csi (Aug 3, 2021)

In order to correct this issue, and use the switch you have, we will need to get inside the motor.  Daytons are sometimes more difficult to reverse because they often don't bring all the necessary wires out, or the internal connections need to be defeated.
We need to determine which two terminals the internal centrifugal switch is connected to.  It will be either between 1 and 2 or between 4 and 5.
The start winding is the red and black leads.  We want to disconnect the end of the centrifugal switch that is currently connected to either 1 or 4 and bring a wire out from that end of the switch.  It may require cutting a copper strap or other such mechanical mod- you won't know till you get a look behind the terminal board.
-Mark
The other option, if you didn't want to open up the motor, would be to use a different switch.  The model that's used to reverse 3-phase motors ("chopstick style") would work without any modification to the motor, using a slightly different hookup. See below


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## Dsjm2005 (Aug 4, 2021)

Ok.  I will take the motor apart and post a pic of what it looks like behind the terminal board.  


markba633csi said:


> In order to correct this issue, and use the switch you have, we will need to get inside the motor.  Daytons are sometimes more difficult to reverse because they often don't bring all the necessary wires out, or the internal connections need to be defeated.
> We need to determine which two terminals the internal centrifugal switch is connected to.  It will be either between 1 and 2 or between 4 and 5.
> The start winding is the red and black leads.  We want to disconnect the end of the centrifugal switch that is currently connected to either 1 or 4 and bring a wire out from that end of the switch.  It may require cutting a copper strap or other such mechanical mod- you won't know till you get a look behind the terminal board.
> -Mark
> The other option, if you didn't want to open up the motor, would be to use a different switch.  The model that's used to reverse 3-phase motors ("chopstick style") would work without any modification to the motor, using a slightly different hookup. See below


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## Dsjm2005 (Aug 4, 2021)

markba633csi said:


> In order to correct this issue, and use the switch you have, we will need to get inside the motor.  Daytons are sometimes more difficult to reverse because they often don't bring all the necessary wires out, or the internal connections need to be defeated.
> We need to determine which two terminals the internal centrifugal switch is connected to.  It will be either between 1 and 2 or between 4 and 5.
> The start winding is the red and black leads.  We want to disconnect the end of the centrifugal switch that is currently connected to either 1 or 4 and bring a wire out from that end of the switch.  It may require cutting a copper strap or other such mechanical mod- you won't know till you get a look behind the terminal board.
> -Mark
> The other option, if you didn't want to open up the motor, would be to use a different switch.  The model that's used to reverse 3-phase motors ("chopstick style") would work without any modification to the motor, using a slightly different hookup. See below


Here is the inside of the motor.


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## markba633csi (Aug 4, 2021)

OK, I need a better view of the back of the board please, a bit closer
I'm afraid to say those windings look a bit toasted-  not a good sign
-M


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## Dsjm2005 (Aug 4, 2021)

markba633csi said:


> OK, I need a better view of the back of the board please, a bit closer
> I'm afraid to say those windings look a bit toasted-  not a good sign
> -M


Here is the back of the board.  The motor was on the old lathe when I got it.  Maybe the windings being "toasted" is part of the problem.  Perhaps it may be a good time to look for another motor???


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## markba633csi (Aug 4, 2021)

Thanks, that's a good picture.  The motor may have some life left in it still, but when the windings get dark like that it usually means the life of the motor may be shortened somewhat. Ironically, the internal thermal protector didn't do much protectin', the case temp wasn't high enough to trip it.
Anyhow,  if you pull off the yellow wire and bring it out,  then put the motor back together, this should get you going again without overheating:
Swap drum switch wires 3 and 4 if necessary to match motor direction with switch handle


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## Dsjm2005 (Aug 4, 2021)

markba633csi said:


> Thanks, that's a good picture.  The motor may have some life left in it still, but when the windings get dark like that it usually means the life of the motor may be shortened somewhat. Ironically, the internal thermal protector didn't do much protectin', the case temp wasn't high enough to trip it.
> Anyhow,  if you pull off the yellow wire and bring it out,  then put the motor back together, this should get you going again without overheating:
> Swap drum switch wires 3 and 4 if necessary to match motor direction with switch handle


I will give that a try.  Thanks so much for being willing to help me with this.


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## markba633csi (Aug 4, 2021)

No problemo, let me know how it goes.  
Be safe
-M


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## Dsjm2005 (Aug 6, 2021)

Ok, so I believe I have it wired per your diagram.  When I plug it in and turn the switch to the forward position I get nothing.  When I turn the switch to the reverse position the motor spins.


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## Dsjm2005 (Aug 6, 2021)

Dsjm2005 said:


> I will give that a try.  Thanks so much for being willing to help me with this.


So I think I have it hooked up as per your diagram.  When I move the switch to the left (forward) position nothing happens.  When I move the switch to the right (reverse) position the motor runs.  For some reason I am not getting power at the forward position.

In the reverse position 1-2-4 terminals are connected along with 3-5-6.  In the forward position 1-2-3 are connected along with 4-5-6.


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## markba633csi (Aug 6, 2021)

Sounds as if one of the contacts isn't making- is the switch cover interfering somehow? Take it off for testing, but be careful. (pull the plug first)
-M
With power disconnected, visually inspect the drum switch contacts to see if any are broken or bent. With cover off, plug it back in and check for 120 volts AC at drum switch terminals 2 and 6 in the forward position.  
Because there is so little room inside the drum switch, the wires sometimes get jammed up by the cover and push the contacts out of position


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## Dsjm2005 (Aug 9, 2021)

I have kept the cover off while testing it.  I do have 120v at 2 and 6 in the forward position but still will not run.


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## markba633csi (Aug 9, 2021)

That's really strange- are you getting any hum at all in forward or is it totally silent?
Post a close up picture of the switch with the cover off- a top view
And a shot of the motor terminal board please, from outside
-M
In the meantime, recheck the wiring matches post #9


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## Dsjm2005 (Aug 10, 2021)

markba633csi said:


> That's really strange- are you getting any hum at all in forward or is it totally silent?
> Post a close up picture of the switch with the cover off- a top view
> And a shot of the motor terminal board please, from outside
> -M
> In the meantime, recheck the wiring matches post #9


Motor is quiet, no hum.  I have attached photos of the switch and motor.  It will be a bit confusing as the wire colors don't match anything.  I just had to use what I had.  I did do a continuity test to make sure they were like the diagram.


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## markba633csi (Aug 10, 2021)

OK, let me peruse it for a bit- I'm sure there's a simple explanation
-M


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## markba633csi (Aug 10, 2021)

I would check for 120 volts ac at the motor in forward, between the #1 post and the yellow wire. You'll need to pull the tape back to expose the yellow wire's terminal- use care. If you have alligator clip leads use them.
-M
The wires in the drum switch look like they could be getting tangled under the switch rotor- check that and re-position the wires if necessary
The drum switch you have is symmetrical, so this indicates a drum switch issue for it to work in one direction but not the other


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## Dsjm2005 (Aug 17, 2021)

markba633csi said:


> I would check for 120 volts ac at the motor in forward, between the #1 post and the yellow wire. You'll need to pull the tape back to expose the yellow wire's terminal- use care. If you have alligator clip leads use them.
> -M
> The wires in the drum switch look like they could be getting tangled under the switch rotor- check that and re-position the wires if necessary
> The drum switch you have is symmetrical, so this indicates a drum switch issue for it to work in one direction but not the other


Well I read through what we have done so far and went back and did a continuity test according to your diagram.  It appears I had 1 and 4 switched at the motor.  I switched them out and it appears to work as it should.  Simply overlooked how they were hooked up.  Again thanks so much for sticking with me on this.


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## markba633csi (Aug 17, 2021)

Good deal, glad you got it going!  It's a good idea to make little masking tape labels when you have several wires
of the same color- helps prevent errors
-Mark


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## Dsjm2005 (Aug 18, 2021)

duly noted on the labels.  Can you help me understand what that yellow wire did and why we moved it from behind the circuit board and brought it to the drum switch?


markba633csi said:


> Good deal, glad you got it going!  It's a good idea to make little masking tape labels when you have several wires
> of the same color- helps prevent errors
> -Mark


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## markba633csi (Aug 18, 2021)

We had to break the internal centrifugal switch away from the connection to the main winding.  Bringing the yellow wire out was the easiest way to do it, since the switch was mechanically connected to the #4 post behind the panel.
When you had it connected before and it was overheating,  it was because the internal switch was shorted out and the start winding was continuously energized. Normally, the winding should disconnect when the motor is up to speed.

On many motors, the red and black wires contain the whole start "leg" - which is the start winding, the cent. switch, and the start capacitor (if equipped)
On yours, the red and black are the start winding _only_- big difference. So when you brought them out to the drum switch suddenly the internal centrifugal switch is not part of the circuit anymore.  Result? The motor runs but overheats.  Dayton motors, later ones particularly, are not designed to be remotely reversed- at least not easily.
-M


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