Cutler Hammer Switch and a Motor

[Jack Olsen]

Electrical stuff is not my strength. In fact, I'm kind of an idiot about it.

I've got a drill press with a simple on-off switch (the one on the left in the fuzzy picture). It has two contacts above and below. When you switch it on, each side's circuit is closed, top left to bottom left and top right to bottom right. The feed coming in has two whites and two blacks, so it seems safe to say that when you turn it off, you interrupt both the hot and the neutral. When you turn it on, you complete each path.

I got a switch that I'd like to replace the toggle-type one with. It's an old Cutler Hammer 10250ED495, with a START button and a STOP button. I assumed this would activate a similar kind of toggle switch function, but it's got me scratching my head. There are four connection points. The two on the left are connected to each other. The two on the right are discreet. When you press the START button, it closes a circuit from left to upper right for as long as you hold the button in. When you press the STOP button, it breaks the connection between left and lower right (but again, only for as long as you hold the button in).

Is it possible to wire this to my motor in the same way the two-line toggle worked previously?

I suspect I've just got the wrong type of switch. But again, this is something where I'm like a 5-year-old child.

Any guidance?

 

[A_Pmech]

Jack,

What you have is a momentary start-stop station, designed for use in a 3-wire start-stop motor starter control circuit.

Latching start-stop fractional horsepower motor control switches are available, but that isn't one. Allen Bradley calls them a "Manual Starting Switch".

 

[Jack Olsen]

Thanks.

That it's the wrong type of switch makes me feel less dumb.

 

[Gary S]

The momentary switch won't work unless you add a latching relay or something similar, and that makes things needlessly complicated. A double pole latching switch would be the way to go.

 

[darkzero]

When I was looking for a simple switch to turn the power on & off for my lathe, I was told to look for a manual motor starter/switch as I didn't want a larger disconnect box.

I got this one made by Square D ($20 on ebay): http://www.grainger.com/Grainger/SQUARE-D-Non-Reversing-Manual-Switch-1H401?Pid=search

Levitron makes them too.

Unlike say a normal light switch, they have a stiff snappy action, my guess is to prevent damage from arcing from the higher amperage.

 

[Stuart in MN]

Using the momentary switch with a relay to latch the power on can be a safety feature - if power is interrupted (say, the power goes out or someone unplugs the drill press) the drill won't automatically turn back on when power is restored. Here's a rough sketch showing how to wire it up.

 

[Steve from Socal]

Jack,

You can buy a small relay from All Electronics for a couple bucks, rated for 1/2 HP.

http://www.allelectronics.com/make-a-store/item/RLY-453/120-VAC-RELAY-DPDT-12-AMPS/1.html

Steve

 

[Jack Olsen]

Well, then it's possible that something functional might rise from the ashes of my poor electronics education.

I just ordered the relay.

 

[Zeke]

Stuart, that is awesome. What a neat safety feature.

I assume one can use that for 120v single phase even though it is capable of 220. That's why it has a 120v coil, right?

 

[Stuart in MN]

Stuart, that is awesome. What a neat safety feature.

I assume one can use that for 120v single phase even though it is capable of 220. That's why it has a 120v coil, right?

That latching circuit is a pretty common way of controlling tools or various other machines. Yes, the relay that Steve posted will work fine for switching 120vac. The latching circuit could also be used to control a contactor or motor starter, for operating higher horsepower devices - just replace the motor in the circuit with the contactor.

 

[Greatbear]

I installed a start-stop contactor (relay) on my table saw many years ago. This came about after I had been working in my basement workshop in the evening and there was a power failure. At the time the saw (a Delta contractor's table saw) had the original toggle switch. When the power went out, I was in the midst of cutting a plywood panel. The saw stopped, and I was in total darkness. I waited for a moment, holding the sheet, since the power failures here are only momentary unless there is bad weather. I gave up waiting and started fumbling for the switch, the power came back on and I was fighting the sheet in an awkward position trying to stop it from kicking back. I managed to finish the cut without incident. After that, I did two upgrades to the shop. The contactor on the saw, which prevents the saw from restarting after a power failure, and an emergency power failure light.

The same problem happened when I was working in the garage in the evening. Power went out, and I was stuck in total darkness under a car. I waited it out, then gave up. I had to fumble my way to the door. I installed a large emergency light in the garage after that.

 

[Teken]

I installed a start-stop contactor (relay) on my table saw many years ago. This came about after I had been working in my basement workshop in the evening and there was a power failure. At the time the saw (a Delta contractor's table saw) had the original toggle switch. When the power went out, I was in the midst of cutting a plywood panel. The saw stopped, and I was in total darkness. I waited for a moment, holding the sheet, since the power failures here are only momentary unless there is bad weather. I gave up waiting and started fumbling for the switch, the power came back on and I was fighting the sheet in an awkward position trying to stop it from kicking back. I managed to finish the cut without incident. After that, I did two upgrades to the shop. The contactor on the saw, which prevents the saw from restarting after a power failure, and an emergency power failure light.

The same problem happened when I was working in the garage in the evening. Power went out, and I was stuck in total darkness under a car. I waited it out, then gave up. I had to fumble my way to the door. I installed a large emergency light in the garage after that.

Wow, that could have ended badly! I added emergency lights in key locations for that exact same reason.

When its 3:00 AM, and -36'C in the garage you don't want to be fumbling around!

Teken . . .

 

[Jack Olsen]

Okay. I've got my relay. Now I know that Stuart in MN has made it plain and simple for someone who knows wiring. But could he (or someone) lay it out even more basically? I've got hot and neutral going in, hot and neutral going out -- and this relay. Can someone explain it in the format of 'hot in to A, neutral in to D, etc.'

 

[PRH44]

Look at the base of your relay there will be numbers on the terminals. They correspond to numbers on my drawing. If you need more just let me know I will follow up with a relay base drawing

[/IMG]

 

[Stuart in MN]

edit: PRH44 beat me to the punch. His schematic will work as well.

Here's a revised schematic showing the terminal numbers (you may need your reading glasses but there are little numbers stamped on the relay.)

Using the letters in your photo:
H = 1
D = 2
G = 3
C = 4
F = 5
B = 6
E = 7
A = 8

 

[Jack Olsen]

Okay. I see the numbers now. Thanks.

They were on the plastic base, not the tabs.

Next step, making the connecting wires.

 

[PRH44]

Here is a connection drawing that may help

[/IMG]

 

[PRH44]

Stuart in MN Sorry I didnt mean to highjack your post!

 

[Stuart in MN]

Stuart in MN Sorry I didnt mean to highjack your post!

Your schematic is prettier.

 

[DekeT]

I so much want a button on/off switch like that for my 1950s black and decker 8 inch grinder restoration. Anyone know where?

 

[Jack Olsen]

It works!

I haven't wired it into the drill press itself, yet. But I made all of the leads and then ran it from a 120v line to one of those ground/hot/neutral plug-in testers and my hot is hot and my neutral is neutral when I push the on switch. And as others mentioned, the cool thing is that when I turn off the source, the circuit switches off and has to be turned on again in order to re-start -- which means after a power outage the drill won't surprise me by coming on when the power is restored.

I know there's no surprise here to the guys who know this kind of wiring. But when it's new to you, it's pretty amazing to see the relay doing its trick.

 

[Stuart in MN]

A simple victory is still a victory.

 

[Jack Olsen]

Agreed. And I'll take 'em wherever I can get 'em.

I've still got to tie everything down so it's out of the way of all the moving parts. And I want to get some longer bolts to hold the switch to the plate. But I put it together and it worked great.

 

[Jack Olsen]

Finished it up.

And I love it. Thanks for walking a slow kid through his first electrical lesson.

 

[A_Pmech]

Looks good Jack, glad to see you and the crew got it figured out. I hadn't thought about using a small motor-rated relay.

 

[Jack Olsen]

Just about every time I walk past the garage, I go in and turn it on and off. That little relay is still like a miracle to me.

 

[slowmo5o]

I found one of these switches at a surplus store. Thanks for showing how to wire it.

 

[1Garageman]

That looks great on it! Nice job.