# Wire a drum switch to a Teco FM50?



## architard (Jul 16, 2012)

This questions is mostly aimed at Ken. I was going to ask it in the thread I had started about my Clausing 4914 but I figured it would be easier for other people to find info specifically about this topic in the appropriate forum. 

Like many others I am also electrically challenged. I've now read almost everything on this site about VFDs and still have questions. I came across a thread that had some information about wiring the drum switch on his 4900 to his Teco FM50. However I don't really understand it. 

I understand that there will be three wires that I need to hook up to the VFD to get the drum switch to work but where do those wires go to since there are 6 terminals? Are there any wires that need to go from one terminal to another terminal within the drum switch to get that to work? 

I have some solid Cat5 cable from work that was being thrown out . Will this work for the low voltage signal wiring? Or should I get something more robust and shielded?

I figured I'd ask Ken since his drum switch will be identical to mine.

Of course this might all be easier with the actual machine and VFD in front of me. I'll have the lathe and VFD in my shop by Sunday. I'm chomping at the bit to get this thing home!


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## Tony Wells (Jul 16, 2012)

Kent, I'm puzzled by the question, a little. If you want the drum switch to handle the reversing, then you shouldn't need it at all. The VFD controls all the motor functions, including direction of rotation.

In general, CAT 5 cable will handle signal level current just fine, and the shielding requirement depends on the sensitivity of the application. I always use shielded when I can though, just because I can. One thing to keep in mind about bulk CAT cabling is that solid is not intended to flex in use. That's why you will see patch cables for computers made from stranded, not solid. Copper work hardens easily, and will break inside the jacket.


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## Kennyd (Jul 16, 2012)

Kent, Read this thread, I posted pics in there: http://www.hobby-machinist.com/showthread.php/3210-Wiring-reverse-off-forward-switch-to-vfd

Re-cap:
1) Strip high voltage wiring from switch (the VFD is wired directly to the motor)
2) Number all the contacts
3) Using a ohm-meter, map out the switch.  Wire down which contact are OPEN or CLOSED at the three different switch positions.
4) Wire low voltage cabling from VFD to appropriate contacts, CAT5 wire is fine but since its has solid conductors it may be prone to breaking from the vibration.  But since you have it use it.

Clears as mud? :lmao:


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## Kennyd (Jul 16, 2012)

Tony Wells said:


> Kent, I'm puzzled by the question, a little. If you want the drum switch to handle the reversing, then you shouldn't need it at all. The VFD controls all the motor functions, including direction of rotation.


He wants to re-wire the drum switch to low voltage to control the VFD remotely.


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## Tony Wells (Jul 16, 2012)

Gotcha. I just see it as dangerous (to the VFD) to put it between the VFD and the motor. No problem doing the f/r wiring to control the VFD.


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## PurpLev (Jul 16, 2012)

Tony Wells said:


> Gotcha. I just see it as dangerous (to the VFD) to put it between the VFD and the motor. No problem doing the f/r wiring to control the VFD.



that is indeed dangerous to put it between VFD and motor, but what Kenny is suggesting is to connecct the drum switch to the FWD/OFF/REV terminals on the VFD using low-voltage circuit - this is not connected to the motor (motor is connected separately and directly to VFD on the LINE high voltage circuit) so this is quite safe, and in fact what the VFD is designed to do

I can probably draw a diagram of this if necessary. although I'm sure Kenny had it covered in the other thread.


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## Tony Wells (Jul 16, 2012)

Sharon,
 I have no problem with doing that. I do wonder though, about the long term effects of using NC contacts in place of momentary contact switches, which is what I have seen on all the VFDs I have used. Never any small ones, just a few between 30 and 200 HP. The controls were all membrane pushbuttons that were momentary contact.


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## PurpLev (Jul 16, 2012)

Tony Wells said:


> Sharon,
> I have no problem with doing that. I do wonder though, about the long term effects of using NC contacts in place of momentary contact switches, which is what I have seen on all the VFDs I have used. Never any small ones, just a few between 30 and 200 HP. The controls were all membrane pushbuttons that were momentary contact.




Tony, I reckon this might be VFD model specific terminal specifications. on the FM50, there are 3 terminal that require a NO/C contacts for the FWD/OFF/REV control of the motor. the VFD relies on these contacts to stay closed for the entire time the motor is supplied with power as opposed to other VFDs that might only requires a momentary electrical signal to signal the controller to send power to the motor or stop it. with the FM50 the rocker switch matches the controllers specifications and requirements and works really well.


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## Tony Wells (Jul 16, 2012)

I admit not having looked at this specific VFD, but if it has rocker switches, then there's absolutely no reason not to sub in a remote 3 way drum switch. Should work just fine.


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## architard (Jul 17, 2012)

Ken was picking up what I was putting down 

I'm a total electronic dolt, but I've at least figured out from reading that you NEVER put anything between the VFD and the motor. 

I think I have a multimeter around here somewhere but the battery may be dead. I watched some YouTube videos on reading resistance on a switch so I think I understand now. I take it since you only need 3 contacts for the remote signal wiring to the VFD you simply aren't using all of the original functioning contacts on the drum switch?

Not sure I completely understand the rocker switch stuff. In the FM50 manual it says depending on your F_11 settings the SW1 switch will change the external signal type to either 0~20mA analog, 4~20mA analog or 0~10VDC analog. Which one do I want to set it to to use a drum switch?

I have dozens of cat5 patch cables here at work so I should be able to snag one of them. The solid wire stuff was already in the trash and being a pack rat I fished it out. I'll probably use cat5 just to get things up and running but I'll eventually replace it with something a bit more robust. 

I tend to follow the motto of Hunter S. Thompson, "if there is anything worth doing, its worth doing right." Although more often than not he was referring to drug fueled benders, not machinery wiring. :lmao:

That's all the dumb questions I'll ask until I actually get it home. )


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## Kennyd (Jul 17, 2012)

architard said:


> I think I have a multimeter around here somewhere but the battery may be dead. I watched some YouTube videos on reading resistance on a switch so I think I understand now. I take it since you only need 3 contacts for the remote signal wiring to the VFD you simply aren't using all of the original functioning contacts on the drum switch?



My meter can be set to "beep" when continuity is found, makes it real handy to test the switch.  Get a new battery in your and I/we can walk you through it-post a picture of it also.




> Not sure I completely understand the rocker switch stuff. In the FM50  manual it says depending on your F_11 settings the SW1 switch will  change the external signal type to either 0~20mA analog, 4~20mA analog  or 0~10VDC analog. Which one do I want to set it to to use a drum  switch?



Don't worry about the  rocker switch stuff.

F_11 is for speed control using the keypad or a external "pot" or "potentiometer" like me.  It has NOTHING to do with FWD-OFF-REV.  Mine is set to 1.

F_03 determines what type of external control (if f_10=1), mine is set for 0.

Yes, the manual SUCKS.  But it will be easier to understand once its hooked up and you can actually play with it.


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## architard (Jul 18, 2012)

Found my multi-meter. The battery was just low. The last time I tried to use it I was like, where is the battery compartment door? Great my multi-meter is trash because I can't change the battery...Yeah, just take the rubber cover off, take out two screws, voila, 9V battery. Idiot.

So yeah, it works fine. It also has the nice "beep" more like a high pitched screech for continuity feature as well. It's not a bad little unit. Should be a piece of cake to figure out the switch now. 

Yeah this manual is confusing. I think I understand it all but like you said, it's going to take having this thing in front of me and playing around with it a little to figure it out. I'm confident with all that I've read and learned from all of you I'll be able to get it going.

Thanks again guys.


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## Tony Wells (Jul 18, 2012)

I have a couple of meters with a continuity beep....that I can't hear unless I hold it right up to my ear. Must be all the ear plugs I used to wear......right, that's it. They're useless to me for that.


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## Splat (Jul 18, 2012)

I think it depends on the VFD's s/w as to what switches would work. On my Teco JNEV-101-H1 I use a NO DPDT toggle switch for the motor direction, but you could use a SPDT. I have a SPST toggle to simply turn on/off the motor. I leave the direction switch in forward and just use the on/off switch to engage the motor.

Kent, the drum switch will be fine, overkill in fact for the circuit but you can't beat its mechanical robustness.

I just looked at the FM50 manual. As to the signal settings:  for the for/off/rev switch you'll be using the FW, REV, and 12V connections on the VFD. The remote potentiometer (if you use one and I suggest you do) would utilize the 10V, MVI, and the 0V (FM-) connections.  For the SW1 switch select the 0~10VDC analog position and ensure parameter F11 is set to 1.

Don't forget to add a ground for your motor and connect it to the PE/ground connection on the VFD...usually next to the T1, T2, T3 connections.


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## -lecroix- (Jul 29, 2012)

I posted it this at another site and basically the reply I got was "read the manual" ... I did. Many times. Still no luck.

I found this site thru a google search on "EV VFD drum switch" and hoped to pick y'all's brain a bit.

I successfully got my 1950 M head B'port up and running using my TECO JNEV-101-H1 vfd, forward and reverse works beautifully with the keypad. But I quickly grew tired of using the control panel on the VFD to turn the mill off and on, change speed, reverse, etc. Not only is it inconvenient to walk to the side of the machine to turn it on, but it's also extremely unsafe. I thought I did my due diligence with research when I decided to use the original drum switch and proceeded to do a bit of test wiring after reading the manual, but quickly discovered out that I apparently don't know what the heck I am doing. 



Here's things as they stand now.

- Used my multimeter to find paths of incoming current to FWD and REV circuits on the drum switch & marked them as such.
- S1 (port #4 on buss)  is assigned to FWD using F11 parameter (factory default 000-FWD) & connected using CAT5 shielded cabling.
- S2 (port #5 on buss) is assigned to REV using F12 parameter (factory default 001-REV) & connected using CAT5 shielded cabling.
- COM (port #8 on buss) is used as my low voltage signal power source & connected using CAT5 shielded cabling.
- Attempted to start motor in both FWD & REV with drum switch - no luck.
- Dove back in to the manual and discovered that F04 needs to be set to 001 (external terminal)
- Attempted to start motor in both FWD & REV with drum switch - no luck.
- Came here and posted this thread.

I also used the multimeter to read the DC voltage coming off the COM (both #8 & #11) and get nothing.  At first I thought it was the drum switch but now am beginning to think I have issues with the VFD.  I tried "jumping" the #8 COM back to S1 and then S2 and got nothing. 

I checked the manual but did not see anything that relates so I wanted to ask if there is there a parameter that "turns off" the COM ports?

Where do I go from here guys? Do I chance frying the VFD by using the 24VDC output as my signal power?

Many thanks ahead of time for any help or advice you guys can offer.


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## -lecroix- (Jul 29, 2012)

Froneck said:


> First question I would think asking was did you run the VFD without the drum switch before you attempted to connect it?
> Your attempting to measure DC volts set to DC on your meter? Measuring the voltage to where?
> 
> Frank



Hey Frank,

As I said above, the mill runs perfectly when operating from the VFD keypad. 

here's a quick vid showing initial power up - http://www.youtube.com/watch?v=JZ9ZyT1W-Kg

The meter is set to DC & I am attempting to measure the 10VDC (per the TECO manual)  from the COM.

Mulitmeter = Red to COM - black to ground.

Here is where another question comes in, have you guys that successfully used a drum-style switch (or ANY switch for that matter that controls FWD & REV) had to change SW1 from PNP input (factory default) to NPN input in order to get the voltage from the COM?

See pic snagged from the TECO manual below.


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## Kennyd (Jul 29, 2012)

How did you map out the drum switch? You should be using the Ohm or Continuity function of the meter, not DC Volts.

Also, you should have started your own thread...


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## -lecroix- (Jul 29, 2012)

Got it! :high5:

I changed SW1 from PNP to NPN, flipped the switch and all is good in the world again! 

A summary of my settings for a TECO JNEV-101-H1 in an effort to help others should they run upon this issue in the future:

Drum switch FWD wired to S1 (buss port 4) & parameter F11 set to 000
Drum switch REV wired to S2 (buss port 5) & parameter F12 set to 001
Drum switch power input wired to COM (buss port 8)
Parameter F04 set to 001 (external terminal)
SW1 set to NPN


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## -lecroix- (Jul 29, 2012)

Kennyd said:


> How did you map out the drum switch? You should be using the Ohm or Continuity function of the meter, not DC Volts.
> 
> Also, you should have started your own thread...



I did indeed use the continuity function of the meter to map out the circuits of the drum switch.  Not sure where you came by the idea that I did otherwise? :thinking:

Anywhoo, my apologies if I stepped on any toes by posting in this thread.  I didn't realize this was against the rules. I thought that by posting here it might possibly help others in the future should they encounter the same issues.  My intent was not to hijack an existing thread but to maybe add some helpful info to it.

Sorry if I offended anyone. :halo:


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## Tony Wells (Jul 29, 2012)

No problem, lecroix. You added substance to this thread, which is perfectly  acceptable. Had you started your own thread, that would have been fine as well, but this worked out. I can separate this out if you like, but I'd prefer to leave it as is.


And welcome to Hobby Machinist!


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