What is this switch symbol? - Page 1
Forum section: electronics / beginners

author: 455Turbo
author_rank: Contributor
timestamp: March 11, 2022, 04:03:39 pm
content: What does the curved line above the highlighted NC pushbutton switch symbol mean?This is for an input to a servo driver.Thanks!

author: TimFox
author_rank: Super Contributor
timestamp: March 11, 2022, 04:45:55 pm
content: The label seems to be an abbreviation for "Emergency Stop" or "Emergency Off".Such switches commonly have a "mushroom" activator, that requires a hard pull out or rotating a lock to de-activate.Random example from the Grainger catalog:https://www.grainger.com/product/32W275?ef_id=EAIaIQobChMIwbWukMG-9gIVUGxvBB2m1AL2EAQYASABEgK35_D_BwE:G:s&s_kwcid=AL!2966!3!496359975016!!!g!438993006185!&gucid=N:N:PS:Paid:GGL:CSM-2295:4P7A1P:20501231&gclid=EAIaIQobChMIwbWukMG-9gIVUGxvBB2m1AL2EAQYASABEgK35_D_BwE&gclsrc=aw.ds

author: CaptDon
author_rank: Super Contributor
timestamp: March 11, 2022, 04:51:17 pm
content: EMGS Emergency Stop The big round red switch you can activate just by falling against it, that is why the curved line, it looks like the head of the switch. You couldn't figure that out??

author: TimFox
author_rank: Super Contributor
timestamp: March 11, 2022, 05:13:23 pm
content: Perhaps he had never seen one before. I first saw one in 1975, but I may be older than he.

author: CaptDon
author_rank: Super Contributor
timestamp: March 11, 2022, 05:37:40 pm
content: I forget what the exact model of Fuji surface mount chip shooter was that the company owned but it had a huge servo driven carriage that could swiftly and easily cut your arm off if caught in the mechanism. It was a 5hp servo motor with about a 100:1 ratio to the lead screw. It had plenty of E-Stops and safety beams and warning labels. The thing was both awesome to watch and the whackiest design for a chip shooter. The circuit board being loaded moved around like a blur and we couldn't shoot large parts like ethernet transformers because they would simply fly off the board!! So we had to have a machine made by Universal to shoot the bigger parts downstream of the Fuji. The 5hp was a calculation of the torque at high speed, but regardless the torque at low 'indexing' speed times 100 was still enough to easily break a 2X4. The machine had to be lag bolted to concrete to keep it aligned and stop it from walking out the door into the parking lot.

author: TimFox
author_rank: Super Contributor
timestamp: March 11, 2022, 05:40:48 pm
content: Often, control systems that use "mushroom" E-stop switches require that after the individual switch has been de-activated (pulled out or unlocked), a separate reset function must be activated at the control room or equivalent before motion or radiation can be re-started.When doing out-of-country installations, I developed a theory that immature individuals loved to hit mushroom switches. This was later verified when a one-year-old was brought by his father to see our lab (all radiation off, of course). The youngster immediately reached out to push the mushroom switch, which was big, red, and attractive.

author: themadhippy
author_rank: Super Contributor
timestamp: March 11, 2022, 06:53:18 pm
content: Worked on a large collage installation several moons back,each of the workshop spaces had e stops ,only problem the clever designer had put the contactor on the incomer of the local dis boards,not individual circuits,so 1 e stop would take out several rooms.Needless to say we were soon back sorting that out,alongside many other errors that we'd pointed out during the build,but was told that was the spec just get on with it.

author: Benta
author_rank: Super Contributor
timestamp: March 11, 2022, 07:32:25 pm
content: Quote from: CaptDon on March 11, 2022, 04:51:17 pmWhy so condescending? This is the Beginners section.

author: CaptDon
author_rank: Super Contributor
timestamp: March 11, 2022, 08:53:23 pm
content: Because observation is the humans most vital and under-used tool. There was the abbreviation EMGS and the industry standard symbol side by side. After pondering a moment and trying to self-solve the mystery I would have liked to see "Is this the symbol for an E-Stop switch"? But Which ever.