CNC Electronics - E-STOP Mockup (Home shop CNC Build Log - Ep17)
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- Опубліковано 15 жов 2024
- I'm getting excited about the electronics on this project now!
I'm a bit of an amateur but this actually works!
Please note that this is not intended as a tutorial. You must do your research and exercise extreme caution when working with mains electricity as it can kill you!
In this video I test and explain the principles behind my estop circuit.
I hope you find it interesting!
My build log can be found at:
3 Axis CNC router
www.mycncuk.com...
Link to my website: www.jrharris.co...
and make sure you check out my other videos.
Please before you advise on emergency stop circuit make sure you are correct
the supply is not switched thru the EM button you have defeated most of the cross wire and short circuit protection offered by the relay
please consult the safety relay manufacturer for correct wiring as this is incorrect in so many ways
agree
@A A please use to wiring diagram that comes with the relay not as shown above as he is incorrect
@A A if you are still having issues then post and l can assist with correct method and logic
It is for the PNOZ X1. Clearly states it in the operating manual.
The short circuit protection is found on the dual-channel safety relay which monitors two channels, this is a single-channel safety relay which requires the 24V supply going through the e-stop to feed A1 on the safety relay
Why didn’t you wire the E-stop across the channels rather instead of killing the supply?
I thought the same, maybe because he only had 1 n.c. contact?
Because this is a single-channel safety relay so the supply to this particular safety relay is the channel.
@@JJGreviews no it’s not. It even shows 2 channels
@@7chappers docs.rs-online.com/16b3/0900766b800331a4.pdf See page 3 of this manual for the PNOZ X1 (the safety relay in this video) which shows how the e-stop circuit should be wired into this single channel safety relay.
Where would you wire them?
13 - 14, 23 - 24, 33 - 34 are the NO contacts switched by the relay.
Y1 - Y2 is the reset circuit
41 - 42 is the one NC contact
That only leaves A1 and A2, A1 being your incoming positive 24V from the safety e-stop loop and the A2 terminal connecting to the 24V negative.
He use PILZ as normal relay - completely wrong.
This doesn't protect against the contactor welding. For that you need two series contactors with NC aux contacts to monitor if either has failed to open. Admittedly probably way overkill for a home DIY project though 😂
Excellent explanation of a proper E-Stop circuit.
E-stop PB should not kill power to PILZ relay - channel 1 ideally both 1&2 should be lost when E-stop. Additional reset button should be used to reset fault after E-Stop being released. Sorry but people should not follow that.
Always switch on / off should be done by the latch, separate NO switch to on and NC switch to off the machine. After the reset, the machine will not start by itself.
Exactly
sorry but this big contactors have all an ac coil or not?
Very good lesson . It all works when your devices are close to each other. How about 2 emergency stops spaced 2000 linear feet apart? Any idea ho w to make it working? Thanks.
Wanting to confirm the operation of the Pilz X1. I can’t find any clear information on it.
When there is 24V across A1 and A2 (supply voltage) AND the connection between Y1 and Y2 (start circuit) is closed the X1 is active and 13-14, 23-24, and 33-34 (the safety contacts) are closed and 41-42 (the auxiliary contact) is open.
Then if the connection between Y1 and Y2 is opened (while there is 24V across A1 and A2) then there is no change to the status of the auxiliary and safety contacts). Is this true?
In other words, the start circuit is only used to enable the X1 after an interruption occurs to the supply voltage. Once the X1 is enabled the only way to disable it is to interrupt the supply voltage (changing the status of the start circuit would have no effect on the safety or auxiliary contacts).
For the X1, the Y1 and Y2 terminals are technically the 'reset circuit', not really the 'start circuit'. If the Y1 and Y2 are linked together then the X1 will automatically reset once the 24V supply to the safety relay is returned. If the Y1 and Y2 terminals have a reset button in series then once the 24V to the safety relay is returned, the operator needs to press the reset button once to link Y1 and Y2 and return the X1 to its normal state.
You're correct in that if the connection between Y1 and Y2 is opened whilst there is 24V across A1 and A2, there is no change to the status of the auxiliary/ safety contacts, this would be a normal situation if the Y1 and Y2 are linked via a manual reset push button.
That was very helpful ! Thanx Joe !
My pleasure! Glad you found it helpful.
Can you put the E-stop right on the AC side?
that is a brilliant video, thank you
I think you do not need a second button to pull in the contactor. The start button should do this once a fault is reset.
I am curious how the BoB is able to trip the e-stop.
Do you have a wiring diagram?
No you need a separate start
Think
You hit a e stop because its an emergency stop
so what ever is running needs to stop in the event of accident or emergency ie machine blocked running out of sync or injerd person ?
Right
well if you reset the estop and the machine started straight away with out investigating or making sure no one is hurt then you'd have a big mess of machinery or possibly dead bodies
This is why skilled trained persons design and wire control panels
Best way to learn is to go to college or night class or a skilled person thats willing to help
not the youtube ive opend my ass up to a court case i saw it on video your honnor way of life
I will not point out many safety error previous mention. The serious error in here is having the A2 of contactor connected into the 33 and 34 NO on safety relay. That is negative or neutral, which if wire touch the frame or anything that makes ground... somebody will get hurt or killed! No even your E. Stop will save them... whatever is connect into this contactor will still runs even if the E.stop is pressed. My advice to people who are learning, please, please do not use this method!
A2 is negative yes, but the voltage depends on what you use. He's using a 24VDC coil, which is far safer than if he was using 230VAC or above.
If the e-stop is pressed, the safety relay will de-energise and the NO contacts which the contactor's A2 coil is running through will open, this will de-energise the contactor since the A2 coil is no longer connected to the negative. Thus whatever is driven by the contactor will stop if an e-stop is pressed.
13-14 to negative terminal is a short. Maybe it is 14-33
The start button should be wired to the safety relay not directly to the A1 on the contactor. The safety relay is only actuating on the negative to the main contactor in your circuitry. Please correct it. This is in no way acceptable to teach to students on your channel.
the e-stop should be wired to a channel. not to the coil.
It's a single-channel safety relay so the 24V from the e-stop has to be wired to A1 on that particular safety relay
"I'm a bit of an amateur but this actually works!" So you don't know if this is the way it is supposed to be and is reliable?
Instead of trolling, go through any of the many application notes available online.
He is incorrect follow the data sheet that came with the relay
He should not be giving advice on machine safety
@@johnonlyonknobbies He's not incorrect, see the data sheet for this particular safety relay - page 3 docs.rs-online.com/16b3/0900766b800331a4.pdf
@@JJGreviews Did you read the description
E-STOP
without detection of shorts across contacts
What's the point of using the safety relay
@@johnonlyonknobbies Yeah - that's what you get with a single-channel safety relay.
It is what it is, it would be better to use a dual-channel safety relay but a single-channel safety relay still at least offers advantages over say using a regular relay i.e. with safety-rated contacts and a built-in reset function, plus they're generally cheaper and less complex than dual-channel relays (it all depends on the context too).
This should be 'how not to wire an em stop circuit'. You should remove this video it's dangerous. Why post if your not an engineer.
sorry but this big contactors have all an ac coil or not?