# VFD on/off switch questions



## Glenn Brooks (Nov 5, 2017)

Hi all,

Looking for guidance on installing an external two button on/off switch with  my VFD stop/start switch to operate themTECO 510 VFD I installed on my three phase pedestal grinder.  The VFD works fine, but does not respond to stop/start commands from the switch.  So I don't know if my wiring configuration is wrong (highly probable) or I am missing some secret set up parameter that TECO doesn't want me to know about-or both.

Can anybody suggest what I should correct or do differently?

Here is the switch and the wiring configuration I set up.  The black lead is connected to the S1 terminal (4th terminal) on  the TECO 510, and the 'power' side of the switch.   The red lead connects to comm and the 'line' side of the switch. This  gives me a 24v reading on my ohm meter across the terminals when I press the start button, and 0.0 v D.C. When I depress the stop button.  But no response from the VFD.






I set the parameters according to the manual for a two button on/off switch as follows:

00-04 [1]
03-00 [0]
03-01 [1]

My second basic question is - how should I read this wiring diagram properl?  It the  TECO manual shows the stop and start terminal leads all apparently jumpered together - into one continuous circuit leading from the S1 terminal in a loop through the switch, back into the 'com' terminal on the VFD?  



This doesn't make any sense, as I am  confused by what COM actually is/does.

Thanks for any help you can offer.

Glenn


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## jim18655 (Nov 5, 2017)

3 wire control needs to be 00-04 [2] from the text in the example,
COM supplies or sinks the power to or from the S1, S2, S3 depending on the power supply. Most likely supplying +24 volts for the circuit.
Pushing the start button turns on S1 which starts the drive until the power is removed from S2 by pushing the stop button. This works like a typical 3 wire start/stop on a motor starter with a latching contact.
S3 selects fwd/rev depending on whether or not the switch is on or off.


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## Glenn Brooks (Nov 6, 2017)

Jim, thanks. I did just set 00-04 to [2] and still nothing happened. E.g. The switch did not turn the VFD on or off.

Also it looks like, in your description, I should add a connection between s2 and a stop button terminal?

Actually I am confused still about what is the correct wiring for the switch. It has two buttons, each with two terminals. Are anymod,these four terminals jumpered to another part of the switch?

Thanks mich
Glenn


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## killswitch505 (Nov 6, 2017)

Com means common it’s the common wire in the Circuit from the diagram you posted you need 3 wires to the switch(s) not counting the ground common is normally black(com) white(S1) red(S2 ) as far as wiring I’m sure there are several different ways but the diagram posted and the switch you have should be wired something like this (you might want to ohm your switches and make sure the stop is normally closed and the start is normally open)


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## killswitch505 (Nov 6, 2017)

Looks to me like the wire you have is only a 2 conductor (we don’t count the ground as a conductor) you can use the ground as a conductor just to test it and see if it works out black as com red as S1 and green as S2 if you don’t have a 4 conductor laying around


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## JimDawson (Nov 6, 2017)

Is that switch a toggle switch?  If it is you'll have to use the two wire control diagram.


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## killswitch505 (Nov 6, 2017)

They look like push buttons


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## killswitch505 (Nov 6, 2017)

The diagram posted the start stop station needs to be momentary contacts in order to work


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## mksj (Nov 6, 2017)

You are use a single maintained switch in a 3 wire configuration, which would need another momentary switch to make it run. The diagram above might also work, but is not correct for 3 wire. If you are only using the grinder in one direction, then I would use 2 wire control. This means when input 1 (Positive terminal) is connected to the COM (Negative terminal) it completes the circuit and the VFD will run forward, break the connection and it stops. You  only need 2 wires, no ground, it is all low voltage DC and almost no current.



When using 2 wire control you need to make the following program changes:
00-02 is set to 1: External Run Stop
03-00 is set to 0: Forward/Stop Command
03-01 is set to 1: Reverse/Stop Command


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## JimDawson (Nov 6, 2017)

I think that switch is push on - push off.  It's a single phase motor start switch.


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## Glenn Brooks (Nov 6, 2017)

Jim, yes you are correct, it is a push -on push-off single phase switch.  Does that make a difference as to what MKSJ suggested? If not, I will configure and try out in the morning...

And, MKSJ, if S2 connects to the off button line terminal,  is it necessary to connect both the off and on load terminals to com?

Oops, killswitch - just read you post. I think that answers my question.  I should go get some three strand wire.

Electrical is fascinating, but not mystrong suit - obviously.

Thanks much!
-Glenn


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## killswitch505 (Nov 6, 2017)

mksj said:


> You are use a single maintained switch in a 3 wire configuration, which would need another momentary switch to make it run. The diagram above might also work, but is not correct for 3 wire. If you are only using the grinder in one direction, then I would use 2 wire control. This means when input 1 (Positive terminal) is connected to the COM (Negative terminal) it completes the circuit and the VFD will run forward, break the connection and it stops. You  only need 2 wires, no ground, it is all low voltage DC and almost no current.
> View attachment 246074
> View attachment 246075
> 
> ...


I’m not understanding the line and the load is this not just a digital input to the drive? I don’t know what drive he has but wouldn’t he need a separate switch to switch forward and reverse? Or would he hit start once for forward and hit it again if he’s wanting to reverse it? Normally on a drive you would give the drive an enable with the start button and give it a Designation of forward or reverse with a forward and reverse switch


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## JimDawson (Nov 6, 2017)

Well, you would use just one pair of contacts and use the two wire configuration per mkjs.

You would also want to provide another switch for For/Rev.


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## mksj (Nov 6, 2017)

S2 is not used unless you wanted to run the grinder in reverse, which I assume you would not do. So with two wire connect the com to S1 and it will continue to run until you break the connection. If you want reverse, connect com to S2 only and it will run in reverse until the connection is broken.  You do not connect both S1 and S2 at the same time to com terminal, the VFD will not run.


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## Glenn Brooks (Nov 6, 2017)

Hi all, this application is a Baldor pedestal grinder. So just one forward rotation, and one speed. So don't expect to need a for/reverse switch- just a large, easily accessible on/off to replace the tiny micro switch on the VFD.

Glenn


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## killswitch505 (Nov 6, 2017)

mksj said:


> S2 is not used unless you wanted to run the grinder in reverse, which I assume you would not do. So with two wire connect the com to S1 and it will continue to run until you break the connection. If you want reverse, connect com to S2 only and it will run in reverse until the connection is broken.  You do not connect both S1 and S2 at the same time to com terminal, the VFD will not run.


I get that on the two wire set up he can’t apply voltage to both S1 and S2 at the same time. So if he’s going to change it to the two wire won’t he need a jumper here? Or no?


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## Glenn Brooks (Nov 6, 2017)

Well, set up the VFD and parameters per MKSJ photo and post.  Switch still doesn't work.    So still stuck..

-g


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## killswitch505 (Nov 6, 2017)

Try putting in the jumper in my last pic


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## Glenn Brooks (Nov 6, 2017)

Thanks Guys!  Adding the jumper made it work!  Better Living Through Electricty!

Very much appreciate your assistance!

Glenn


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## JimDawson (Nov 6, 2017)

mksj said:


> S2 is not used unless you wanted to run the grinder in reverse, which I assume you would not do. So with two wire connect the com to S1 and it will continue to run until you break the connection. If you want reverse, connect com to S2 only and it will run in reverse until the connection is broken.  You do not connect both S1 and S2 at the same time to com terminal, the VFD will not run.



I forgot we were working with a grinder here.


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## killswitch505 (Nov 6, 2017)

Glenn Brooks said:


> Thanks Guys!  Adding the jumper made it work!  Better Living Through Electricty!
> 
> Very much appreciate your assistance!
> 
> Glenn


If you would have wired it like the first pic and had the setting set to 3 wire it would have worked as well doesn’t matter if the stop or run button is a holding contact. As long as the stop is normally closed and the start is normally open


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## markba633csi (Nov 7, 2017)

LOL electric fun.  Watching with a grin.  Glad you got it working Glenn
Mark S.


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