Need help wiring a foot pedal into a 220 line going to stationary sander

[Mark R Webster]

I am trying to add a foot “on and off” switch to my 220 line going from the wall to my stationary sander. I have 2 hots and 1 ground coming from the wall. The foot switch (designed for 110 or 220) has 3 wires, a black, a white and a green. Do I take one of the hots from the wall and connect it to, say, the black going to the switch and attach a second wire to the white coming from the switch and continue the second wire to the terminal/tool where the hot would have gone if I were not using the switch? I assume the ground wire from the switch would be added to the ground coming from the wall heading to the tool?

[Mike Henderson]

I'm going to guess from your description that your foot switch is a "single pole, single throw" (SPST) switch. You can use an Ohm meter to check continuity when you press the switch.

If it's an SPST, I'd use it to control a 120 volt DPST contactor, which would control both sides of the 240 volt line. While opening one side of a 240 volt line will stop the machine, it leaves the other (hot) side of the 240V line connected to the machine.

Mike

[Mark R Webster]

This is the switch. https://www.ssccontrols.com/product/s400-1002-s-series-light-duty-foot-switch-front-hinge/

[Bill Dufour]

This is the switch. https://www.ssccontrols.com/product/s400-1002-s-series-light-duty-foot-switch-front-hinge/

They show the internal wiring diagram. It is a single pole switch only rated for ten amps. How many amps on your motor? If you have a switch upstream of this one it may be okay if your shop is not inspected.
Bill D.

[Mark R Webster]

The tool is rated at about 7 amps using 220

[sean meltvedt]

Mark, follow Mikes advice and use a contactor (aka big relay) to open both legs. You really don’t want to leave one powered, it could cost you everything!
cheers
Sean

[Rollie Meyers]

It is code compliant to only break one leg of a 240V circuit as long as it is not the disconnect, which a foot switch cannot be. The practice of only breaking one leg of single phase, or 2 legs of 3 phase 240V loads is pretty common. I don't particularly care for it but from a code standpoint, it's permitted. A 220V circuit has 1 hot leg, and a neutral, and is 50 Hertz, and is the norm in most of the world outside of North America.

[Curt Harms]

I'm going to guess from your description that your foot switch is a "single pole, single throw" (SPST) switch. You can use an Ohm meter to check continuity when you press the switch.

If it's an SPST, I'd use it to control a 120 volt DPST contactor, which would control both sides of the 240 volt line. While opening one side of a 240 volt line will stop the machine, it leaves the other (hot) side of the 240V line connected to the machine.

Mike

What he said. I've used special purpose contactors that can be purchased pretty cheap and put in an electrical box. You don't need the overload protection that is part of a starter, do you?

[Jim Becker]

Mark, follow Mikes advice and use a contactor (aka big relay) to open both legs. You really don’t want to leave one powered, it could cost you everything!
cheers
Sean

I agree. A contactor is the safest way to handle this and the foot pedal can be low voltage for control.

[Mark R Webster]

I am sorry Mike I am having a hard time understanding what is being recommended. I am not familiar with a 120 V DPST. Again I am not an electrician... are you suggesting I can use the pedal I have, but for safety I need to install a 120 volt DPST contactor in the line? Would it be:
Wall >SPST pedal> 120 volt DPST contactor> machine
or
Wall > 120 volt DPST contactor> pedal> machine?

Can someone point me to a link for one of these contactors? Is the contactor also called a relay? How can one put a 120 device in a 220 system?
Are you guys saying that "technically" I could wire as I described in my first post but it would be dangerous because with the pedal in the off position, one of the wires heading to the tool is still hot. Note, there is an on and off switch on the tool that would come after the foot pedal switch. So if wired as I described initially, the hot portion of the line (pedal in the off position) would be between the pedal and the tool in front of the tool's on and off switch.
Sorry for being dense on this.:confused:

[Joe Kaufman]

In addition to the problems listed above, is this what you really want?
It will only be on as long as pressure is applied to the foot switch.


From the wiring diagram - "Action:
momentary (press and hold to turn on, release to turn off)"

I would consider adding a warning light to indicate the foot switch is hot meaning it will start the machine.

You should also consider a guard over the switch to prevent accidental activation.

[Mark R Webster]

My understanding was this pedal was not a "momentary" type in the description it says:

"Action: maintained (press once to turn on, press again to turn off)"

[Jim Becker]

Mark, a contactor is like a relay if it helps you understand it's function as a switch. It has two sides...control and line. The line side has to be rated for the voltage and amperage for the tool to be switched. The control side can be low voltage or 120v AC, depending on what you buy. Here's a graphic of how I use a contactor for my cyclone...the theory would be the same for your tool with your foot pedal replacing the wall switch I use for my setup.

https://zfxh5g.bn.files.1drv.com/y4mZS-zKt-6OmEpbIcG5h3VT6C0zYE0HdOIiNwVkbrJ2pAgWRaWtBkuCbWfq T12hrNjKWIFyzdkX1rtiS421WJ4WEhYaGTF51BsgIl_57f5qeC sCp9xgHJBKFqCl7OdP74qi_INCNY68M43iWkYpX8slEzL1vsDw 2xhFFYaXrdOPKU9ysQWlbvlMeBGee-0N2R4vC-N7K7zNurn7liDVS67Ig?width=660&height=380&cropmode=none

[Joe Kaufman]

Mark, your link goes to a S400-1002 which is a momentary type.

[Mark R Webster]

Sorry Joe, my error I meant it to go to the the other pedal.

[Mark R Webster]

Thanks Jim I will have to study this for a while.

[Mark R Webster]

Just an update, I contacted the company who makes the foot switch I noted above and they recommended I not use it for this application for the reasons you guys have mentioned in this thread. They sent me to another manufacturer who I contacted and am ordering a different pedal... a DPDT. We'll see how this looks hopefully more straight forward for someone like me ;)

[Jim Becker]

Mark, if this is a 240v tool, you need to check and see if you can even use a simple DPDT switch with it. A lot of these tools use mag switches or motor starters and it's important to know what's required before you spend money.

[Mark R Webster]

Hi Jim, Thanks for the advice I will check into it.

[Mark R Webster]

Ok…. I ordered/and received a new/different foot pedal/switch. To my surprise, it has no schematic included and no wiring instructions. But, upon taking it apart, I identified the actual switch inside. (different manufacturer). The rest of the unit is just a mechanical exterior.
Again, I am not an electrician so excuse my ignorance. Here is a link for the switch inside the exterior http://products.omron.us/Asset/DZ_10G_datasheet_en_201109.pdf . I am trying to figure out how to wire it up. I am coming from a 240V 20 A outlet at the wall with 2 hots and a ground. There is a spot for the ground on the foot pedal body. The switch product number is DZ-10G-1A1 and is made by Omron. It has the pin plunger and solder terminals. Looks like 6 places one can attach wires, two labeled COM, two labeled NC and two labeled NO. Looking at the “Structure” description on the datasheet, it appears one would attach the hots from the wall to the Com1 and Com2 and the outgoing “hots” could attach to the NC or NO connections. The info says the NC and NO refer to Inrush currents. NC is 30 A max and NO is 15 A max. The tool only uses 7 amps with 240. Can someone describe which connectors I should attach the 2 hots from the wall to and which connectors I should attach the outgoing “hots” to?

[John Lanciani]

NC is Normally Closed, NO is Normally Open. This is the state of the contact at rest. If you want the machine to run when you press the pedal you use the normally open contacts.

Is the switch you have momentary or continuous? (Do you have to keep your foot on the pedal to keep the machine running, or is it press on, press off?)

[Mark R Webster]

The switch is described as Maintained (press on / press off). So... would I connect the incoming hots, one to each "COM" and the outgoing hots one to each "NO" terminal?
Thanks
If your wondering why I am not asking the pedal's customer service, I have called them once and they were kind of rude and I got the feeling they were irritated that I was asking questions. That was when I was asking which pedal to buy. I am afraid I will get the "idiot" treatment... "just hire an electrician" .... "why are you asking me these questions?". :mad:
pics from switch manufacturer's documentation

398375398376398377

[Ronald Blue]

There are far more qualified people than I to chime in here. As John stated you will use the normally open terminals. I'm not a fan of unguarded foot switches. The dangers are obvious in some applications. Someone mentioned earlier to get a guard and it's good advice. I think a disconnect might be a good idea here as well. Or unplug when not in use. You could use one side of the normally closed contacts to turn on a power light whenever the circuit is energized. Just as a reminder it was "live". This is pretty straight forward circuitry here. Good luck.

[Mark R Webster]

Thanks Ronald, this switch is enclosed in a very sturdy cast iron foot pedal frame. I can set up a guard as you described, in addition though. Does my description of where to put the wires make sense and is it appropriate? Sorry for being dense, I just don't want to do this in an unsafe way. :o

[John Lanciani]

You may well burn that switch up using it to start an induction motor,it doesn’t appear to have a horsepower rating. A typical 1 hp induction motor running at 240 volts is going to have 40-60 amps of inrush current, it looks like the switch is only rated to pick up 15 amps. A .5mm contact gap is also going to have a hard time breaking the load.

Did the manufacturer or distributor sell sell it to you as a motor rated switch?

ETA - I just took a close look at the mfr spec sheet, that switch is only rate for a 1/4 hp or 1amp inductive load at 240 volts AC. It will probably fail the first time you try to use it on your sander.

[Mark R Webster]

I told the tech support guy from the pedal company that I was going to use it on a Jet stationary belt sander. He indicated that it would work...?

[Dan Friedrichs]

He was wrong. You're going to have a hard time finding a DPDT switch that can run a load this large - at this scale, it makes WAY more sense to use a contactor, so that's what people would do. You need to do what Mike suggested - use the switch to control a relay (contactor).

[Mark R Webster]

Thanks Dan

[Jim Becker]

Please look again at the diagram I provided in post #13. Replace the switch with your foot pedal (what you have will be fine) and the cyclone with your sander. That's all you need to do what you want to do safely. Contactors are made for this purpose. The "control" side can be 120v or low voltage...whatever you prefer. Just buy a contactor that matches what you want on the control side and has the appropriate current rating on the load side. Mount the contactor in a small electrical enclosure (I used a tiny "load center" cabinet and ripped out the breaker provisions to just use the box)

https://sawmillcreek.org/attachment.php?attachmentid=11455&d=1097973512

[Mark R Webster]

Thanks Jim!!

[Mark R Webster]

Ok I think I finally got it :) I sent the last pedal back and have ordered components to mimic Jim's set up. I think I am on my way to a safe solution.
Thanks for all the advice guys.

[Jim Becker]

Sounds like a plan, Mark. While you are waiting for your parts, you might want to see if there is a convenient place to mount the box for the contactor right on the sander, maybe on the back or an end panel. That way, you can hard-wire the machine to the load side of the contactor and just have one plug to go to the wall on the line side plus accommodation for however you have decided to handle control voltage. Think it through and it will work out nicely!

[Mark R Webster]

Thanks for all the help Jim!