emergency stop bar

Yeah, the whole system. You don't want the equipment starting back up when you let go the kill switch.

Two examples using the Cinny 1B

The drum switch on the head is inherently latching. You turn it to off, it stays off when you let go. The power buttons on the column are both momentary. They don't latch themselves. However, the wiring of the contactors they control is latching. Push the start button and the contactor closes. release the button, the switch opens, but the contactor stays latched closed. Push the stop button, the contactor opens and stays open until the start button is pushed again.
 
Can someone please identify what self latching and direct opening means?

Thanks!! Daryl MN

Written by lawyer too. Part of understanding that stuff is knowing who wrote it and his definition of what different words mean. Not easy to do for me.

To be concise, My thought on the E-Stop Push button switch

-1- No springs in PB , latch open and closed
-2- Big Red mushroom top with lip so you can pull it back out after it is pushed.
-3- Proper labels ( Regs on that too I think)
-4- Location requirements
-5- different device is used to restart the system after e-stop event ( after the E-Stop PB is pulled out.)
-6- Contacts on E-Stop are typical Normally Closed in operational state. Goes open when activated. If a wire breaks it has same effect on system.
-7- functionality schedule ( how often is the system tested to be functional? probably a regulation on that)
-8- all E-Stops have to do the exact same thing with system. If you don't better have good documents and safety reviews as to why.


Typically , I wire my E-stops in one series string and then that drives a Safety relay. A separate PB is used to reset the E-stop string and safety relay. Feedback from each E-stop is run to computer system so the program can take action on the E-stop event as well. Program will act like it has to shutdown the system as if power is still somehow still there.

I like having power still on my PLC's and computers so I have use of programs and datalogging events. Typically have UPS's on them as well for same features as Power goes off when crazy events happen. [ had a ninja peaceful activist this year protesting capitalism and he climbed a power pole and was being all crazy, he fell off and hit power lines , shut the area down for a bit ]

Remember if something bad happens and you got dead bodies around, you will have investigators and OSHA hovering over you asking questions and looking to target someone for the event. Jail time and $$$ fines is the prizes to be given out.
 
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Many lathes have a mechanical foot brake, a long bar which is also connected to a NORMALLY CLOSED limit switch. This is only considered a stop function but it will quickly stop the lathe in an emergency situation. The unlatch function is essentially the same as a stop button in a typical relay logic latch rung circuit. This braking stop function can be very helpful when single point threading since the lathe stops very quickly and the operator can retract the cross feed in a less of a "panic" state. The motor stops both mechanically as well as electrically.
 
Can someone please identify what self latching and direct opening means?

This is a huge help! And, it makes sense....
Thanks to all.
I was understanding this to somehow refer to the "can" or "enclosure".

It's discussions like this which teach me stuff and allows me to ask better questions, and do fun stuff more safely!

Daryl
MN
 
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Sure you could arrange a microswitch with a bar tied to a latching relay or contactor-but
how big of a lathe are we talking about and how big are the kids?
would it not be easier to just move the existing switch so they could reach it easier?
Mark

There are foot switches that are alternate action, that is one "tap" turns on and the next "tap" turns off. You could interface higher loads with a contactor.
 
There are foot switches that are alternate action, that is one "tap" turns on and the next "tap" turns off. You could interface higher loads with a contactor.

Those are amazing switches in the right application. Can't remember who makes them, I remember buying them before thou.

As stated earlier, be careful with whatever type hardware you decide to use with an E-stop. The government regulation that term might cause a headache n the future. The easy fix is to not call it an "E-Stop".
 
If your lathe has a no-volt-release for incoming power (which it should, IMHO), the stop bar can operate a normally closed microswitch wired in the NVR's coil return (in series with the existing stop button) built into the bar's pivot, or even better one each end so that should the bar twist when stamped on you have two chances for it to operate (to be sure, to be sure, as they say in the Old Country) - if you can link it to a brake to stop the spindle faster or another relay to e.g. operate the VFD's Estop* if you have one, it can make awkward threading jobs easier too?

A remote Estop's a good idea, so your loved ones don't have to step over your corpse and dodge flailing limbs to stop that annoying thump-thump-thump noise - again wire in series with the existing Estop circuit.

Dave H. (the other one - did the above while converting lathe, on the VFD, also linked in a "neutral" switch on the Fwd/Rev lever to disable the power-on button if it's "in gear")

* Most VFD's hold enough power with the input AC disconnected to brake to a stop in an emergency - YMMV!
 
My e-stop is pull electric cord from receptacle. I have most of my machines wired up with L14-30 receptacles and plugs. Do have fused safety switches at each machine, too.
 
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