Mechanical delay.

[itsmoked]

Long ago I saw one of these but now that I could actually use one....nada

I want to prevent someone from starting a motor more often than every 15 minutes.(EVER!)

I have electronic timing so I can start a 15 minute timer that prevents hitting start again until it times out. But you get the clever/stupid operator who figures out that if power is lost the timer resets. Then they just crank off the disconnect and then back on, and away they go with a 30 second cycle.

I have seen mechanical bellows(?)types that essentially cock with the initial turn on then take x minutes, regardless of the power situation, to re-close.

Anyone have a lead, or know what these are called? Or have an effective alternate solution? Google bombed for me.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[ScottyUK]

Hi Jeff,

Regarding arc energy: I'm no expert but I'm currently trying to raise awareness of the risks of arcing faults at our site. I thought the ratings were based on available fault level and protection characteristics rather than the amount of bare copper? Or are there a different set of regs I'm totally ignorant of? We're trying to apply the intent of the NFPA 70E standard on our British equipment and it is proving interesting. There is a lot of resistance to wearing the Category 3 and 4 suits because of the discomfort levels. A few have remarked that any task which is dangerous enough to require us to wear a 'space suit' should not be done live.

Sorry for dragging this OT!


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I don't have an attitude problem. You have a perception problem...

 

[itsmoked]

Feel free it's no problem on the tail of this thread what-so-ever.

Those big fuses are current limiting and this panel is served by a 100A breaker. Seems like a substantial amount of limiting.

Hey Jeff, how about a napkin arc-flash calculation on this thing.

What info does one need to start with?

Or is it a royal pain in the butt-don't want to do it task?

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[HCBFlash]

oooooooooo

http://wwwwwwwwww!

Scotty!



Some folks like myself have to troubleshoot and service (even occasionally modify or re-wire) equipment like this, and many of us HATE much imported equipment with IEC type components and practices, because accesibility is a consideration.

Yeah, that disconnect and the fuseblocks are really a bit much,,,, but it's no more dangerous than euro-stuff - always too tightly packed in - with the covers removed for troubleshooting, and test probes nearly touching each other and other devices because of those tight clearances.

 

[ScottyUK]

...always too tightly packed in...

Bad design is just bad design, wherever it is built. I send designs like that back to the designer covered in red pen and rude phrases! I have to live with the stuff we design - I'm on call one week in six - so I have a take-no-prisoners attitude with designers who use crappy components loaded right up to their rating and who squeeze things in too tight.


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I don't have an attitude problem. You have a perception problem...