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South Bend Furnas RSB4 reversing controller

Steve_Furby

Plastic
Joined
Dec 10, 2020
Help, I've searched high and low on wiring the above switch and can find nothing on wiring 8 terminal switches. The continuity is as follows. Looking at the switch with the F/N/R at the top.
Forward 1/2, 3/4, 7/8
Reverse 3/5, 4/6, 7/8
Motor is capacitator, inductance, forward/reverse Craftsman 1/2 HP
I cannot read the diagrams on inside cover of the Furnas switch. Any help would be appreciated.
a28beec17fc7883feea1d50e0ab0b144.jpg
ecf9be72bd2bb697a0435b50bcd34310.jpg
fd54c5156eafadaaca7e5391934aafdf.jpg
850990480bca92081f2445fe30b6020f.jpg


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evanthayer

Aluminum
Joined
Jun 13, 2018
Can you post an image of the face plate on your motor?


Help, I've searched high and low on wiring the above switch and can find nothing on wiring 8 terminal switches. The continuity is as follows. Looking at the switch with the F/N/R at the top.
Forward 1/2, 3/4, 7/8
Reverse 3/5, 4/6, 7/8
Motor is capacitator, inductance, forward/reverse Craftsman 1/2 HP
I cannot read the diagrams on inside cover of the Furnas switch. Any help would be appreciated.

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Steve_Furby

Plastic
Joined
Dec 10, 2020
Here is the picture. Also one of the pictures of the Furnas pictures iscariot duplicate.
f2c715ceb2ca8c7fef4b75e9e13ccb8a.jpg


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evanthayer

Aluminum
Joined
Jun 13, 2018
Okay, 3 more questions:

1. Any chance you can find a more detailed wiring diagram for this motor? It doesn't look like they have surfaced enough wires for you to connect up for forward & reverse. A modern reversible AC capacitor start / run motor surfaces (6) wires in total plus a ground wire. You wire these in specific (2) groups of three and connect up to mains to run the motor forward. If you swap (2) particular wires from one group to the other you get reverse. Without being able to identify these connections it is outside of my understanding. I've attached the motor plate from my modern motor for an example.

2 motor plate 2.jpg

3 motor plate 3.jpg


2. What machine are you hooking this up to? My SB 9A runs with a 1725 RPM motor and your motor looks like 3500 RPM. Do you have the right speed motor for your application?

3. How are you numbering your contacts? I attached a sketch of what I think you are saying. Have you confirmed this with a continuity tester?

IMG_9796.jpg


Let us know.

Evan
 

Steve_Furby

Plastic
Joined
Dec 10, 2020
Okay, 3 more questions:

1. Any chance you can find a more detailed wiring diagram for this motor? It doesn't look like they have surfaced enough wires for you to connect up for forward & reverse. A modern reversible AC capacitor start / run motor surfaces (6) wires in total plus a ground wire. You wire these in specific (2) groups of three and connect up to mains to run the motor forward. If you swap (2) particular wires from one group to the other you get reverse. Without being able to identify these connections it is outside of my understanding. I've attached the motor plate from my modern motor for an example.

View attachment 347438

View attachment 347437


2. What machine are you hooking this up to? My SB 9A runs with a 1725 RPM motor and your motor looks like 3500 RPM. Do you have the right speed motor for your application?

3. How are you numbering your contacts? I attached a sketch of what I think you are saying. Have you confirmed this with a continuity tester?

View attachment 347439


Let us know.

Evan
The label on the motor says reverse red and black to change direction. I numbered the Furnas switch across from each other
1---2
3---4
5---6
7---8

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Steve_Furby

Plastic
Joined
Dec 10, 2020
My drawing, and yes you are right, the motor is to fast. It is what came with it.
e28c97acbde008f518a694d9679e86ed.jpg


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Steve_Furby

Plastic
Joined
Dec 10, 2020
Maybe I can pull it apart and see what wires are hooked behind terminal board.

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Steve_Furby

Plastic
Joined
Dec 10, 2020
I believe you are right. Shaft goes right through. I am looking at another motor, but I still can't figure out South Bend Furnas switch.

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The eight pole configuration is not to be found on the internet. The switch RSB4 is out there but nothing on hooking it up. Any help would be appreciated.

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Dobermann

Hot Rolled
Joined
Jan 2, 2014
Location
North Carolina
First, if that is a 3500 RPM motor as the nameplate seems to say, then it's really an inappropriate motor for a metal lathe. Using any reasonable motor pulley size, your countershaft and spindle speeds will be way too high.

Second, all single phase capacitor start motors are not necessarily reversible. Some have the start winding connections "hard wired" inside the motor and you can't separate the start winding leads which you must do in order to reverse the direction of the motor.

I think you may need a different motor.
 

Steve_Furby

Plastic
Joined
Dec 10, 2020
First, if that is a 3500 RPM motor as the nameplate seems to say, then it's really an inappropriate motor for a metal lathe. Using any reasonable motor pulley size, your countershaft and spindle speeds will be way too high.

Second, all single phase capacitor start motors are not necessarily reversible. Some have the start winding connections "hard wired" inside the motor and you can't separate the start winding leads which you must do in order to reverse the direction of the motor.

I think you may need a different motor.
I am getting a different motor. The motor came with boxes of pieces of a Southbend 9C lathe I have rebuilt. I am at the wiring up stage and would like to run it. The cover on the motor says it is reversable. Change red and black. I am trying to figure out the Furnas RSB4 reverse controller switch. I can find lots of information on 6 terminal switches, but nothing on 8 terminal. I have already confirmed motor is working.

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evanthayer

Aluminum
Joined
Jun 13, 2018
You can always purchase a 6 terminal furnas switch (i assume you know this and are going for the old fashioned look.) The McMaster-Carr part no. is #7065K21. Not inexpensive but much better than a new motor ($59.77). For my 9A I used a new switch with the old handle.


I am getting a different motor. The motor came with boxes of pieces of a Southbend 9C lathe I have rebuilt. I am at the wiring up stage and would like to run it. The cover on the motor says it is reversable. Change red and black. I am trying to figure out the Furnas RSB4 reverse controller switch. I can find lots of information on 6 terminal switches, but nothing on 8 terminal. I have already confirmed motor is working.

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Dobermann

Hot Rolled
Joined
Jan 2, 2014
Location
North Carolina
OK, let's review:

Your job as the main electrician is to figure out how to apply line voltage to the run winding of the motor and line voltage to the start winding of the motor. In order to change the direction of the motor, you need to reverse the terminals of the run winding as they connect to the line but leave the run winding connection polarity the same as it was.

Those rotary switches provide a means of doing that. The photos of your switch are not really clear enough to figure out a recommended terminal connection scheme but you should be able to figure out how to do that by carefully looking at how the switch connects the various terminals in either direction.

Regardless of what motor you use your assignment will still be the same--run winding polarity remains the same and start winding polarity is set either one way or the other. If you reverse the polarity of both the run winding and the start winding the motor direction won't change.
 

Dobermann

Hot Rolled
Joined
Jan 2, 2014
Location
North Carolina
you need to reverse the terminals of the run winding as they connect to the line but leave the run winding connection polarity the same as it was.

Well, there's a little mistake there. It's supposed to say .....you need to reverse the terminals of the START winding but leave the run winding connection polarity the same as it was.

Sometimes my brain doesn't keep up with my typing fingers!
 

Steve_Furby

Plastic
Joined
Dec 10, 2020
you need to reverse the terminals of the run winding as they connect to the line but leave the run winding connection polarity the same as it was.

Well, there's a little mistake there. It's supposed to say .....you need to reverse the terminals of the START winding but leave the run winding connection polarity the same as it was.

Sometimes my brain doesn't keep up with my typing fingers!
I had to take a break from it. I finished off an old Jet drill press and am inspired to tackle the Furnas switch again. Thanks for your intrest, i will keep you posted.

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