Emergency stop switch

[kwame]

I want to install an emergency switch for my project.I want some guidance on how to wire successfully with the loads,and the main ON/OFF switch.
I geuss it must be in series with the loads.Or not?This is the best technology forum on the planet.

KWAME

 

[carbonzit]

Sorry to complain--you're not the only person here guilty of this--but how the hell do you expect us to help you when you give us no information? We can't read minds, you know. Too many people here post vague questions like this, expecting us to fill in the blanks for them. Well, we can't. Describe your problem more completely, please.

What kind of "emergency switch"? What exactly do you want it to do? Connected to the power line connection? What voltage? What kind of on/off switch is already installed?

I have no idea if this will apply, but here's an interesting little on/off switch using a relay, known as a "locked-out relay". The ON and OFF switches are momentary pushbuttons. The ON switch energizes the relay, closing its contacts, which then complete the circuit through both switches, holding the relay coil energized. To shut it off, the OFF switch opens this circuit, releasing the relay contacts.

**broken link removed**

This is the type of circuit used in many industrial power controllers--you've seen them: a box with two big buttons, one marked "START", the other "STOP". Hitting the red "STOP" button will immediately de-energize the controlled device.

 

[KMoffett]

carbonzit,

I want to install an emergency switch for my project.

I think the mistake kwame made was to assume that everyone is following his other threads.

And, your emergency stop circuit is the best, because if the power fails the system will not automatically restart on the power returns.

Ken

 

[kwame]

Explana.

Hi
the voltage is 240VAC and at the moment i have used a toggle switch.I want to install the emergency switch for added safety.The emergency is going interrupt power to motors,light and heating elements in case of emergency.Got it?

 

[Reloadron]

Attached is another variation of the circuit that was already posted. Additional normally closed switches could be placed in series for additional E stops with the first switch. In this example the control voltage is 24 VDC and the switched voltage is 240 VAC. The data sheet for the relay RY1 can be found here as a refrence. There are a dozen ways this can be modified or adapted to suit your needs. If for example you want all 220 VAC control then use a 220 VAC relay coil.

Ron

 

[carbonzit]

Hi
the voltage is 240VAC and at the moment i have used a toggle switch.I want to install the emergency switch for added safety.The emergency is going interrupt power to motors,light and heating elements in case of emergency.Got it?

The circuit I posted will do that. All you need to do is hit the momentary-contact OFF switch (normally-closed), and the whole thing will shut down immediately. If the power goes out and is restored, it will still be de-energized until someone hits the ON switch.

Ron's circuit is the same thing, but with the relay coil operated with low voltage (from a transformer) instead of line voltage. Either one will work fine.

 

[Dean Huster]

E-stop switches are ALWAYS to be normally closed -- open to stop. That way, a defective (usually open) circuit doesn't allow the circuit to run and neither will it not work to stop the circuit as a normally open switch in an open circuit would.

 

[KeepItSimpleStupid]

What do you want to happen after a power failure?

Where is this emergency stop switch relative to the project. I had to put mushroom switches outside the door of the lab. Purpose was to ensure personal safety (ppm levels of the gases we were dealing with was toxic and one was pyrophoric when exposed to air, and Hydrogen was explosive), one leaves the lab first and then shuts it down. 24 VAC signalling to avoid conduit. Buzzers and strobes would be activated if their was a gas detection and if the fire alarm went off, the lab shut down.
That's an emergency stop.

This is a big difference between a emergency stop switch mounted on a panel.

My crystal ball is still broken and I can't read minds. Please be more descriptive,

 

[Dr_Doggy]

all you need is a breaker a little over your max current value, @your voltageVac, , YES in series, YES on primary circuit,

you can leave toggle switch in too, in series

If you put toggle parallel with breaker, then toggle can bypass breaker, but not good to bypass a tripping breaker!!

 

[Reloadron]

all you need is a breaker a little over your max current value, @your voltageVac, , YES in series, YES on primary circuit,

you can leave toggle switch in too, in series

If you put toggle parallel with breaker, then toggle can bypass breaker, but not good to bypass a tripping breaker!!

Doggy, I don't think a circuit breaker is a good substitute for an "E" Stop switch. This is why we have E Stop circuits.

Ron

 

[carbonzit]

Well, I know for sure it ain't a good substitute, since the idea is to protect something that may fall into water, which won't necessarily draw enough current to trip a breaker, but could definitely conduct enough electricity to harm or kill a person.

 

[Reloadron]

Well, I know for sure it ain't a good substitute, since the idea is to protect something that may fall into water, which won't necessarily draw enough current to trip a breaker, but could definitely conduct enough electricity to harm or kill a person.

Naw, that was the other thread. This is the:

Hi
the voltage is 240VAC and at the moment i have used a toggle switch.I want to install the emergency switch for added safety.The emergency is going interrupt power to motors,light and heating elements in case of emergency.Got it?

Ain't this fun?

Ron