# YASMT: Allen Bradley Mag switch wiring for Single Phase



## calgaryguy (Mar 13, 2022)

"Yet Another Standard Modern (9") Thread"

My former-SAIT Standard-Modern 9" Utilathe came with a 3ph 1/3hp 1725rpm motor. I've replaced it with a 3/4hp Baldor single phase 1800rpm motor.

The SM base has a control panel with on/off buttons and a fwd-rev switch







All good, @YYCHM provided a wiring diagram from the manual showing how to wire the front control panel for 220v 1ph.

My challenge now is wiring the Allen Bradley Mag switch located inside the cabinet

















I've googled for  "allen bradley 709 taf" with no luck. Is there anyone out there familiar with these mag switches or knows of a internet resource with AB manuals? I know modern mag switches are usually 1ph and 3ph capable depending on how they are wired. Are these older AB mag switches the same?


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## calgaryguy (Mar 13, 2022)

I may have already answered my own question by reading the 'Connections for Single Phase' in the pic 1st row, right. RTFM. Lol.

I have 2-3 of these AB mag switches around, but the lack of a more complete manual makes me nervous to use them. I dont like letting 'magic smoke' out of electrical bits.


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## YYCHM (Mar 13, 2022)

LOL.... One peek in that box and I'd be off to PA to buy a drum switch

That and a big a.s paddled ESD switch to hang on the front of the stand.


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## calgaryguy (Mar 13, 2022)

All good. I should be able to 'figure' it from the writing on the inside of teh cover.

The wiring is alot more complex than usual as there is a remote on/off, a reverser, AND a power disconnect switch that SAIT seemed to have added at the belt housing cover. I'll post a pic when I get a chance - suffice to say its a button switch that the belt housing cover pushes against to allow power to flow. When teh cover is open the button goes to a 'closed' state.

EDIT:


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## YYCHM (Mar 13, 2022)

calgaryguy said:


> All good. I should be able to 'figure' it from the writing on the inside of teh cover.
> 
> The wiring is alot more complex than usual as there is a remote on/off, a reverser, AND a power disconnect switch that SAIT seemed to have added at the belt housing cover. I'll post a pic when I get a chance - suffice to say its a button switch that the belt housing cover pushes against to allow power to flow. When teh cover is open the button goes to a 'closed' state.



Seriously????


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## calgaryguy (Mar 13, 2022)

YYCHM said:


> Seriously????


I edited the post above with pics ^^^^^^^


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## YotaBota (Mar 13, 2022)

Instructions???????? We're men,,,,,,, we don't need no stinkin instructions!!!!!LOL
I was rescued by the VFD, wired the drum switch to the VFD and used the red/green buttons to control the contactor feeding the VFD.


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## YYCHM (Mar 13, 2022)

YotaBota said:


> I was rescued by the VFD, wired the drum switch to the VFD and used the red/green buttons to control the contactor feeding the VFD.



What was that on?


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## calgaryguy (Mar 13, 2022)

YotaBota said:


> Instructions???????? We're men,,,,,,, we don't need no stinkin instructions!!!!!LOL


Having let the 'magic smoke' out of a few electrical devices in my life I'd rather be cautious. Especially with a brand new, never run, Baldor motor and a 220v 30A circuit. Lol


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## YotaBota (Mar 13, 2022)

The SM1120, the story is in my cleanup and rewire thread.








						SM1120 Finally found one!
					

I put a wanted ad in the used,ca looking for a SM1120 in November and just before xmas I got a message that there was one coming available. I picked it up yesterday!:D It doesn't appear to have a lot of use but it's pretty grimy. The motor is 3ph but there was no power to the machine so I...




					canadianhobbymetalworkers.com


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## YotaBota (Mar 13, 2022)

calgaryguy said:


> Having let the 'magic smoke' out of a few electrical devices


Been there done that, I spent 34 years in electronic machine maintenance so the concept isn't new to me. lol


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## YYCHM (Mar 13, 2022)

calgaryguy said:


> I edited the post above with pics ^^^^^^^



That would be the first thing to go, if it were mine

Is the RWD/REV switch on the stand a honest to goodness drum switch?  Wouldn't that solve the 1PH wiring problem entirely?


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## calgaryguy (Mar 14, 2022)

YYCHM said:


> That would be the first thing to go, if it were mine


I kinda like the safety factor. No reason not to keep it.



YYCHM said:


> Is the RWD/REV switch on the stand a honest to goodness drum switch?  Wouldn't that solve the 1PH wiring problem entirely?


I dont know if it is or isnt. I think your 'drum switch' is a reverser and a on/off switch combined, not sure 
.
I'm going to be running it on 220v, and I'd prefer to leave the magnetic switch in place - that way if I kick a breaker or the power goes out while I'm using the lathe theres no chance of the machine spinning back up when power is restored. This is standard on all my heavier woodworking gear.

Besides, getting it work under 220v 1ph shouldnt be an issue once I do some 'figuring' on the existing wiring. The AB mag switch is the complex part. Having the factory buttons on the front work keeps its 'originality' IMO.

EDIT: Adding a big 'oh shit' paddle safety switch in an easily slappable place like @YYCHM 's is something to consider.


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## Gearhead88 (Mar 14, 2022)

YYCHM said:


> LOL.... One peek in that box and I'd be off to PA to buy a drum switch
> 
> That and a big a.s paddled ESD switch to hang on the front of the stand.


Careful , the anti drum switch'ers are watching you


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## Darren (Mar 14, 2022)

Gearhead88 said:


> Careful , the anti drum switch'ers are watching you



not saying a word....


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## combustable herbage (Mar 14, 2022)

Darren said:


> not saying a word....


I think Craig would put a drum switch on the shitter if he could!!


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## Darren (Mar 14, 2022)

combustable herbage said:


> I think Craig would put a drum switch on the shitter if he could!!


Thankfully the shitter doesn't have reverse


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## RobinHood (Mar 14, 2022)

Ok guys, no need to let the smoke out of anything…

Nobody says you need to connect the Power Side of the contactor while you are establishing the Control circuit. Two separate items, at least in my view. I only ever connect the Power Side after I am 100% sure that the control circuit works properly. That means:

a) the FWD /Neutral/REV switch is wired properly
b) the contactor Control is wired correctly
c) the door safety switch is in the circuit properly
d) the green Start switch is working properly
e) and the red Stop switch is working properly

Other than the contactor coil, none of the components need line voltage to test the circuit - a little 9V battery will work just fine ==> no smoke.

Now onto to the circuit:

Make sure the AB contactor‘s coil is rated for the voltage of your control circuit.  The only sure way to know is take the contactor apart and look at the coil physically.

The grey switch with the handle is a FWD / NEUTRAL / REV switch. It needs to be wired such that in Neutral (Center) position, the control voltage to the contactor is interrupted.

The door safety switch is the “Master Switch”. If it is “open“, no matter what button(s) you press, the lathe must not start.

The green Start button is the only control that makes the contactor coil close - after the direction of rotation of the spindle has been preselected by the FWD/N/REV switch. The red Stop switch is the normal way of turning the lathe off. If you were to use the F/N/R switch while the lathe is running, the contactor will open and the motor stop.

The whole thing needs to be wired such that, after a line power failure, the contactor opens and stays open until the operator decides that they want to run the lathe again after the line power comes back on.

The circuit needs to be set-up such that it latches the contactor after the green momentary Start button has been depressed - but only with the door safety switch closed AND a direction of rotation preselected.

When I had the 9” Utilathe, that’s how it was set up. I believe there are wiring diagrams available online for the Rotary switch that is installed in your lathe.

Here is the wiring diagram for the SM1120. It has the exact same controls (minus the door safety switch) as your 9“ Utilathe. It shows 3 phase motor(s), but that does not matter. Just use two (L1 & L3) of the lugs of the contactor instead of three. Make sure the “heaters” can handle the current of your single phase motor. Get properly rated ones once you have the circuit established and are ready to connect the load. Wire the door safety switch in series as the first item in your control circuit. Test everything with low voltage DC.


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## calgaryguy (Mar 14, 2022)

All good @RobinHood . I've got teh wiring 95% sorted.

The old allen bradley mag switch needed, as you stated, new motor heaters. What a gong show to source those today. I went to Westburne 4 times and they kept telling me that they only had heaters for Rockwell systems. James Electric, Nedco, and another shop in Calgary all told me 'Go to Westburne for Allen Bradley heaters' as I tried each of them.

It wasnt until I found the attached pdf at the Rockwell Automation site, printed it off, and went back to Westburne and showed them that "yes, you do have heaters for AB equipment" that I got teh right heaters. I dont fully blame them - its probably a 50(?) year old motor starter from a company that was assimilated into Rockwell 30+ year ago.

Oh, for the record, I ended up with W44 heaters. 4.4a draw at 1.15 load factor and the W44's were closest in rating (and in stock).


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## YYCHM (Mar 14, 2022)

What are motor heaters?


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## Darren (Mar 14, 2022)

YYCHM said:


> What are motor heaters?



overload protection devices not found in a drum switch


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## Brent H (Mar 14, 2022)

Tis a bummer - I just tore one out of Miss Metric and it is sitting in the attic acquiring a new patina.


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## calgaryguy (Mar 14, 2022)

YYCHM said:


> What are motor heaters?







__





						Magnetic Starters - VintageMachinery.org Knowledge Base (Wiki)
					

Expanation of Magnetic Motor Starters




					wiki.vintagemachinery.org


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## Brent H (Mar 14, 2022)

@YYCHM : I had never heard of the thermal overloads referred to as heaters - mind you, I am not in the shore side electrical business but “overload”, “trip”, thermal protection, thermal etc etc, absolutely- took me a bit to figure out what was going down.  You really do not want “heat”  so I guess it is the same as calling an electrician a “sparky”.  Pretty undesirable- LOL


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## Brent H (Mar 14, 2022)

A website with electrical slang:





__





						Electrical Slang Terms | Warshauer Electric Supply
					

Industry & Trade Terms and Definitions for Common Electrical Industry Slang




					www.warshauer.com
				




Evidently confusing for electricians as well.


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## RobinHood (Mar 14, 2022)

Sorry for the slang term. It does describe their mode of operation very accurately: a resistive coil of wire heats up based on current flow which then opens a by-metallic switch and thus interrupts the circuit causing the contactor to unlatch. This is what protects the motor from overload. The “heaters” (the resistance wire) is sized based on allowable current of the load. Works very well. And yes, they do get hot and glow as the max protection current is flowing through them.


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## calgaryguy (Mar 15, 2022)

RobinHood said:


> View attachment 21977


@RobinHood, if I disregard L2/T2 (which is what my AB mag switch inside cover diagram/instructions says to do also) to use 1 phase power, does the motor not need a line voltage input?
( I should add that my AB inside cover additonally says to 'disconnect 'X2' from L2 and run it to L3 which I have done - its a small gauge wire that runs from the right side of the coil).



 





Ie: @YYCHM posted a 1000 series wiring diagram which is for 220v 1ph but shows 3 wires going to the motor:




This ^^ diagram shows a lead that runs from T1 to position 4 on the reverser switch and from postion 4 on the reverser to one line on the motor, or simply a line from T1 to a line on the motor.

Does that make sense? If so, how do I wire my motor leads to accomodate these 3 connected lines? Im in a little over my head how to wire my motor leads

Heres the wiring diagram for my Baldor L3507 (which is reversible)


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## YYCHM (Mar 15, 2022)

Is there a wiring diagram on the motor itself?  Some times it's on the back side of the connection box cover plate.


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## calgaryguy (Mar 15, 2022)

There is, but it doesnt apply to a reversing scenario with 3 wires coming into the motor.






I've wired dozens of 1ph 220v motors with mag switches before, just never with a reverser and a on/off switch remote from the mag switch.


It would seem to me that the lead from the T1 terminal on the mag switch needs to be connected to both position 4 on the reverser and to wire 1 on my baldor motor (either in series or in parallel). Then a lead from position 2 on the reverser switch to wires 4+5 on the motor, and finally a lead from position 3 on the reverser to wires 2+3+8 on the motor. Does that make sense?


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## YYCHM (Mar 15, 2022)

Which diagram applies here low or high voltage?


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## calgaryguy (Mar 15, 2022)

YYCHM said:


> Which diagram applies here low or high voltage?


240v is how I'm setup to feed this machine.


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## Brent H (Mar 15, 2022)




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## Brent H (Mar 15, 2022)

I think my above wires be correct for what your doing?  Select direction and push the button - might need to see which way FWD and REV is


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## calgaryguy (Mar 15, 2022)

Maybe I dont fully understand but are you suggesting that there should be 5 separate lines connected to the motor? If so, that doesnt sound right.


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## RobinHood (Mar 15, 2022)

I concur with @Brent H ’s diagrams and comment about possibly having to switch out motor leads 5 and 8 if the direction of rotation is opposite from what you need to match the F/N/R lever position.


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## Brent H (Mar 15, 2022)

Well, you can take the two wires at switch connection 2.  (Wires to motor 2/3) and just run 1 to the motor with a jumper across 2/3

You will have a few wires going to the motor if you want reverse.


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## RobinHood (Mar 15, 2022)

calgaryguy said:


> Maybe I dont fully understand but are you suggesting that there should be 5 separate lines connected to the motor? If so, that doesnt sound right.


Yes. You are letting the F/N/R switch on the panel do the connecting of the correct wires in order to control the motor‘s direction of rotation AND cause it to drop off line if you happen to move the switch while the motor is running.


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## RobinHood (Mar 15, 2022)

@Brent H and I posted at the same time: Brent’s comment in post #36 is a more elegant solution and reduces the wire count by one. Go with that.


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## calgaryguy (Mar 15, 2022)

Brent H said:


> Well, you can take the two wires at switch connection 2.  (Wires to motor 2/3) and just run 1 to the motor with a jumper across 2/3
> 
> You will have a few wires going to the motor if you want reverse.


So thats 

T2 (t3 in my case) to motor 1
Reverser switch 1 to motor 8
Reverser switch 2 to motor 2+3
T1 to reverser switch 3 to motor 4
Reverser switch 4 to motor 5

So 5 leads in total to the motor?


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## YYCHM (Mar 15, 2022)

That's pretty much what I had to do on my lathe.  6 leads if you want to run a ground through.


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## calgaryguy (Mar 16, 2022)

I'll give this a shot today sometime. My regular job is getting in the way... LOl


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## calgaryguy (Mar 16, 2022)

Its alive. I took a video, but the forum wont let me upload it. Lol.

Forward/Reverse, stop/start, moving from fwd to middle/rev to middle AND the side cover 'safety switch' all work as intended.


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## YYCHM (Mar 16, 2022)

BRAVO.....Well Done.....


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## calgaryguy (Mar 16, 2022)

Couldnt have done it wthout you gents, thanks.


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## RobinHood (Mar 16, 2022)

Congrats! Well done.



calgaryguy said:


> I took a video, but the forum wont let me upload it. Lol.


You can use a program called “Streamable.com”. You upload the video onto their platform and then they give you a link which you can post here. The basic version is free.


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## calgaryguy (Mar 16, 2022)

RobinHood said:


> Congrats! Well done.
> 
> 
> You can use a program called “Streamable.com”. You upload the video onto their platform and then they give you a link which you can post here. The basic version is free.











						IMG_2353
					

Watch "IMG_2353" on Streamable.




					streamable.com
				




Fyi, you may note that I have the lead screw, saddle and apron removed. No need to panic.  Cleaning and inspection.

One last note. I didnt run a ground wire all the way to the motor from the junction box where the incoming line comes in. The incoming line is grounded to the juntion box which is metal and is bolted to the base. This is the way the 3ph motor was configured. Thoughts? Any risks here? My woodworking 220v stuff always has a ground run to the motor via a bond at the mag switch.


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## YYCHM (Mar 16, 2022)

The lathe didn't appear to stop when you opened the belt cover?


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## calgaryguy (Mar 16, 2022)

YYCHM said:


> The lathe didn't appear to stop when you opened the belt cover?


It absolutely did. Watch again. 1:06 in.


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## PeterT (Mar 16, 2022)

@calgaryguy Is it my imagination or at 0:36 when you switch in reverse, chuck is rotating in forward direction? (CCW if viewed on end from tailstock). 
I couldn't make out the other starts by the time chuck was moving


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## calgaryguy (Mar 17, 2022)

PeterT said:


> @calgaryguy Is it my imagination or at 0:36 when you switch in reverse, chuck is rotating in forward direction? (CCW if viewed on end from tailstock).
> I couldn't make out the other starts by the time chuck was moving


rotations are correct, must be a trick of the camera


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## 6.5 Fan (Mar 17, 2022)

Sounds nice, congrats


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