# Dc motor emergency switch



## Hologram1954 (Jun 30, 2013)

Im in the process of getting the parts together for a treadmill motor conversion on
my 9x20 lathe, The one thing I'm not sure about is how to wire an emergency stop 
switch to the KBIC 240d controller.Any suggestions would be appreciated.


----------



## hey-bear (Jun 30, 2013)

just add a estop switch inline with the lead that is connected to the AC input (L1) on the board. If your lathe is a recent Chinese one, then just connect the controller to the Start/Stop Switch combo.






Hologram1954 said:


> Im in the process of getting the parts together for a treadmill motor conversion on
> my 9x20 lathe, The one thing I'm not sure about is how to wire an emergency stop
> switch to the KBIC 240d controller.Any suggestions would be appreciated.


----------



## Hologram1954 (Jun 30, 2013)

Thanks for the reply, There are two inhibit switch connections on the 240D controller board wasn't sure if they could be used.

Update...
Just found a section in 240 manual stating inhibit not to be used for emergency stop and to use AC Line only ...


----------



## hey-bear (Jun 30, 2013)

Right, if the controller fails shorted, the motor will run and the inhibit switch won't work.


----------



## rdhem2 (Jun 30, 2013)

In your case using the AC line to open the circuit a momentary STOP pushbutton will not work.  As soon as the button is released the motor will try and start again.  This time you need a maintained stop button.  Like an ordinary switch left in the "ON" position.  You can purchase maintained emergency stop buttons also.  Good luck and good machining.


----------



## Hologram1954 (Jun 30, 2013)

The switch I have is the push to stop and has to be rotated to reset which I guess would start the motor at the speed it was 
when the stop was pressed. I got into the habit of pressing the e stop after switching off spindle speed when I removed something from
the chuck on my previous lathe.


----------



## TOOLMASTER (Jun 30, 2013)

I added one on hot wire of 110..for my lathe


----------



## Hologram1954 (Jun 30, 2013)

Yes thats the type of switch I have.


----------



## JimSchroeder (Jun 30, 2013)

Hi Hologram1954, I have a Grizzly 10x22 and I believe that you will find some similarity between the wiring layout of your lathe and the Grizzly.  I converted to a DC drive several years ago, I am attaching a doc that outlines how I completed the task.

A couple of comments on the general idea controlling motors on machinery.  First, emergency stop must remove power to the unit, not inhibit power via a secondary circuit.  This is generally done by using a main contactor to provide power to the unit and provide power control.  The main contactor is activated by a secondary control circuit which is part of the "Run, Emergency Stop" switches on the front panel.

The front panel on my lathe also has a "Forward, Off, Reverse" switch and I wanted to retain that functionality.  The attached schematic includes those functions.

View attachment G0602 DC Motor.bmp

View attachment G0602 DC Motor2.bmp

View attachment Variable speed motor.doc


I hope this helps, let me know if you require more detail.

Jim


----------



## Hologram1954 (Jun 30, 2013)

Well my lathe is pretty much the same as the grizzly g4000 and ill be using the KBIC 240D controller with an AC feed on/off switch and a forward stop reverse on the DC feed.Thanks for all that info Jim.


----------



## dwdw47 (Jul 1, 2013)

As a real emergency stop, you could use a double pole/double throw switch wired to open both motor leads and then to short the motor leads together to brake the motor by using it as a generator to stop it. A 20+ ohm resistor would keep from exploding anything!
Just a thought
dwdw47


----------



## Hologram1954 (Jul 17, 2013)

All now sorted thanks for all the advice given...


----------

