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Old August 15th, 2022, 09:00 AM   #1
pennywise
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Emergency Stop (E-Stop) Wiring Options - Dual Channel

Hi,

I would like some recommendations/advice on wiring of a dual channel Emergency Stop for a 240V AC motor (single phase), I have 3 options in mind, please see image below, which option would you recommend? and why?

Note that for overload protection, I will add a MCB as the first device connected to 240V AC (so before the E-stop).

Thanks!

Note that I'm using a non-safety PLC to keep the cost down as there would only be 1 (or possibly up to 3) E-Stops in the system so safety PLC isn't required I guess.
Attached Images
File Type: png emergency stop wiring options.png (179.8 KB, 225 views)

Last edited by pennywise; August 15th, 2022 at 09:08 AM.
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Old August 15th, 2022, 09:14 AM   #2
L D[AR2,P#0.0]
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None of them, you need an Estop relay that will check both channels and a reset.
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Old August 15th, 2022, 09:16 AM   #3
geniusintraining
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You probably need someone on that side of the pond to give you the standard

I have seen it several ways but most of the time the e-stop kills all control power to the panel including the PLC
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Old August 15th, 2022, 09:27 AM   #4
pennywise
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Quote:
Originally Posted by L D[AR2,P#0.0] View Post
None of them, you need an Estop relay that will check both channels and a reset.

Oh yes, you're right, I completely forgot about the reset functionality!

As without reset, if someone released the E-stop by mistake, it would be dangerous.


Can you recommend a E-stop relay for a single phase motor?
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Old August 15th, 2022, 09:39 AM   #5
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Quote:
Originally Posted by pennywise View Post
Oh yes, you're right, I completely forgot about the reset functionality!

As without reset, if someone released the E-stop by mistake, it would be dangerous.


Can you recommend a E-stop relay for a single phase motor?
estop relays like a 440r-S12R2 will have a dual channel with pulse testing (so a short to 24v or faulty contact won't allow it to work when it shouldn't).

you would run your estop circuit starting at the relay itself, then run the 2 channels through the 2 NO contacts on the Estop and back to the relay. Then reset can be done with any NO contact on a reset button.

Capture.JPG

Last edited by IanM8040; August 15th, 2022 at 09:42 AM.
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Old August 15th, 2022, 09:46 AM   #6
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Have a look at this https://www.pilz.com/download/open/P...2215-EN-06.pdf
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Old August 15th, 2022, 09:50 AM   #7
pennywise
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Quote:
Originally Posted by IanM8040 View Post
estop relays like a 440r-S12R2 will have a dual channel with pulse testing (so a short to 24v or faulty contact won't allow it to work when it shouldn't).

you would run your estop circuit starting at the relay itself, then run the 2 channels through the 2 NO contacts on the Estop and back to the relay. Then reset can be done with any NO contact on a reset button.

Attachment 62806

Excellent, thank you IanM8040


If I want to add another 1 or 2 e-stops, it would be okay to put them in series with the existing e-stop, all using the one same e-stop safety relay right?
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Old August 15th, 2022, 09:53 AM   #8
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Originally Posted by pennywise View Post
Excellent, thank you IanM8040


If I want to add another 1 or 2 e-stops, it would be okay to put them in series with the existing e-stop, all using the one same e-stop safety relay right?
they just go in series. the only things that causes the pulse outputs to stop working is running them over so long of a distance, that the resistance in the lines distorts the waveform over the 340us it sends out
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Old August 15th, 2022, 09:54 AM   #9
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I agree with Max, look at the Pilz website, there are plenty of manuals with drawings showing many types. Plus these are availlable from many sources even RS they even have the Datasheets.
I suggest you include a N/C contact from the main contactor in the reset, this then will disable the reset should the contactor weld in, also feed the PLC outputs from one of the guided contacts from the safety relay.
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Old August 15th, 2022, 10:52 AM   #10
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Quote:
Originally Posted by geniusintraining View Post
You probably need someone on that side of the pond to give you the standard

I have seen it several ways but most of the time the e-stop kills all control power to the panel including the PLC
Sweet Jesus, NO NO NO NO NO BAD BAD BAD

Then all kinds of unintended things can happen, and you have no wait good wait to tell the operator or any connected systems what is going on.
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Last edited by theColonel26; August 15th, 2022 at 11:19 AM.
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Old August 15th, 2022, 10:56 AM   #11
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Quote:
Originally Posted by geniusintraining View Post
You probably need someone on that side of the pond to give you the standard

I have seen it several ways but most of the time the e-stop kills all control power to the panel including the PLC
I wire mine in a way that it removes power from all but one output card. Not the power to the PLC. This leaves a powered up PLC and output card to alarm on the HMI and sound a horn as well as energize lights on a light stack.
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Old August 15th, 2022, 10:56 AM   #12
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Originally Posted by theColonel26 View Post
Sweet Jesus, NO NO NO NO NO BAD BAD BAD

Then all kinds of unintended things can happen, adn you have no wait good wait to tell the operator or any connected systems what is going on.
right....

the standards of safety only start at killing power to drives and motors. NOT the PLC itself.

When going a step above, a wait til to kill the outputs happens, giving the system enough time to bring itself to a controlled stop, and then cutting power.

safer than that goes above, by locking all doors and entrances to the machine while this processes is happening, until full stop occurs.





lots of layers of safe/safer/safest these days. but just imagine a VFD that normally would regen back into a resistor to slow a motor down after being given a stop command, now think what happens if all power is cut and it just spins down on it's own, but someone goes into the area of operation with a spinning motor and a faulty clutch.
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Old August 15th, 2022, 11:06 AM   #13
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Quote:
Originally Posted by pennywise View Post
Hi,

I would like some recommendations/advice on wiring of a dual channel Emergency Stop for a 240V AC motor (single phase), I have 3 options in mind, please see image below, which option would you recommend? and why?

Note that for overload protection, I will add a MCB as the first device connected to 240V AC (so before the E-stop).

Thanks!

Note that I'm using a non-safety PLC to keep the cost down as there would only be 1 (or possibly up to 3) E-Stops in the system so safety PLC isn't required I guess.

None of those for Motor E-Stop.

Anything that has the potential to cause immediate injury, like mechanical forces. Needs at least 2 parallel Signal Channels, and a reset function. (In my Opinion and Experience with customer requirements)


The US is very loosey goosey with safe-circuit design standards it completely depends on the end users requirements, on how they want them designed.
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Last edited by theColonel26; August 15th, 2022 at 11:19 AM.
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Old August 15th, 2022, 11:09 AM   #14
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Quote:
Originally Posted by IanM8040 View Post
right....
I thought this was sarcastic

Quote:
Originally Posted by IanM8040 View Post
the standards of safety only start at killing power to drives and motors. NOT the PLC itself.

When going a step above, a wait til to kill the outputs happens, giving the system enough time to bring itself to a controlled stop, and then cutting power.

safer than that goes above, by locking all doors and entrances to the machine while this processes is happening, until full stop occurs.





lots of layers of safe/safer/safest these days. but just imagine a VFD that normally would regen back into a resistor to slow a motor down after being given a stop command, now think what happens if all power is cut and it just spins down on it's own, but someone goes into the area of operation with a spinning motor and a faulty clutch.
Then I read the rest of your post and you seem to be agreeing with me. (and provided needs details that I did not)
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Last edited by theColonel26; August 15th, 2022 at 11:19 AM.
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Old August 15th, 2022, 11:54 AM   #15
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Originally Posted by theColonel26 View Post
I thought this was sarcastic


Then I read the rest of your post and you seem to be agreeing with me. (and provided needs details that I did not)
sorry, the ellipsis can mean different things to different people.

I agree with what you said and just elaborated a little bit.
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