EM Stop Buttons

[gaulty]

It's been awhile!

need a little help on how to wire 4 Em stop buttons for Four work bays at a college through a contactor so if I hit any of the stop buttons it would knock off all four.

contactor would be normally closed, it's just wiring back through the coil I'm not too sure on. You would be lucky if there's 13Amp in total for all the bays.

my idea was to take put each bay on its own cct, wire from breaker to contactor and contactor to bays and have coil through em stop but how do I wire coil so that if I hit any stop button it opens contactor.

my original idea was to have a stop for each bay which only did that bay but client isn't wanting that, he want any stop button to kill power to them all

 

[telectrix]

what are the bay supplies? 3 phase or 1 phase?

 

[Bobster]

What's your college instructor say?

 

[Leesparkykent]

What's your college instructor say?

His profile says he's approved.

 

[Bobster]

His profile says he's approved.

Oh dear...

 

[Richard Burns]

Wire your power off buttons in series to the coil.

 

[telectrix]

His profile says he's approved.

so was the school i attended for 4 years.

 

[Pete999]

Is it 4 separate circuits or just 1? Sorry didn't see the bit in your post saying 13 A total, so one circuit then yes? N/C contactor supplied from it's own OCPD or looped off of the live in the contactor in series with a stop button through a line type fuse of the appropriate size, power goes off contactor goes O/C fail safe same as if someone hits the stop button.

 

[dansk]

Would it not be best using Normally Open contacter? And wire the ES buttons on a ring?

 

[davesparks]

Would it not be best using Normally Open contacter? And wire the ES buttons on a ring?

Yes a normally open contactor should be used to give fail safe operation.
Stop buttons should be wired in series. I can see what you mean by calling it a ring, but that could cause confusion with a normal ring circuit and end up with someone wiring them in paralell.

 

[Pete999]

Would it not be best using Normally Open contacter? And wire the ES buttons on a ring?

Yes I suppose it would and careful consideration, my initial post saying N/C would be fail safe is wrong.

 

[netblindpaul]

You must undertake this work in accordance with BS4163 as it is a Code of Practice for educational workshops basically.

 

[UKMeterman]

Also have a read of BS EN 13850

 

[Darkwood]

Many requirements here the OP hasn't even considered and as others have expressed with relevent BS regs means you cannot just design a functional circuit without knowledge of these requirements, as this set-up will be classed as a safety critical system you need to be sure you know what your doing, I did one many years ago before there were any real regulation and guidelines and I design it to a standard that i bet would still pass modern guidelines.

- It will require to be fail-safe however the design is done
- I assume there will be some requirements for key reset system so only a keyholder ( e.g tutor or trained assistant) has the capability of energising the bays.
- Dependent on the nature of the hazards their may be requirement for alternative E-stop actuators like a foot or push bar.
- Consideration will be needed for equipment that may be a hazard if suddenly energised but I'll be surprised if such equipment will be been used in the college to start with.


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[netblindpaul]

Basically DW 4163 is the "c type" standard for this type of install, iykwim.
This will lead you to the other standards and requirements.