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E Stops used in Lab areas

Andy

Hello All,

              I'm looking for a cost effective way of introducing E Stops to Lab and Clean room power circuits. Some of these are rows of single phase sockets on benches in test and evaluation areas and others are complete power shut offs for 3 phase power to production equipment. These circuits would literally be Emergency use only as the name suggests. I don't really want to use contactors on the socket circuits mainly to reduce the the possibility of added noise on the lines.

Question is

a) Has anyone had experience with shunt trips or bolt on modules to existing RCDs for the socket circuits these could be fitted locally with the reset under lock and key in the plant room. Is there a best practice for this type circuit?

b) Most three phase equipment in these areas have E Stops built in but the requirement is to isolate the complete room. So the more I think about it the more I'm considering a main contactor or shunt trip device on  the output of the   equipment UPS. It is possible the UPS may have a facility for this but it's not obvious.

If anyone has experience in this field please advise.

Much appreciated

Andy

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  • 0

    how serious is it when the Estop fals to stop ?

    in descendoing order...

    Death ?

    Shock?

    Loss of equipment ?

    wasted electricity?

    For the first 2., and possibly the first 3, you need Conventional Estops which are normally closed, push to break, and those would be series wired to a contactor that is held in under power but spring loaded to break so if a button is pressed or power is lost, the result is the same. To use shunt trips.  there needs to be a logical inversion and an acceptance that the system does not always fail to safe - as such it is not a safety of life sort of Estop, more of an off switch that saves you walking accross the room.

    Now that may be perfeclty OK for your purpose, but you should probably not call it an E-stop to avoid confusion.

    Mike.

Reply
  • 0

    how serious is it when the Estop fals to stop ?

    in descendoing order...

    Death ?

    Shock?

    Loss of equipment ?

    wasted electricity?

    For the first 2., and possibly the first 3, you need Conventional Estops which are normally closed, push to break, and those would be series wired to a contactor that is held in under power but spring loaded to break so if a button is pressed or power is lost, the result is the same. To use shunt trips.  there needs to be a logical inversion and an acceptance that the system does not always fail to safe - as such it is not a safety of life sort of Estop, more of an off switch that saves you walking accross the room.

    Now that may be perfeclty OK for your purpose, but you should probably not call it an E-stop to avoid confusion.

    Mike.

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