Local isolator

MrJack96:

Hi guys I’ve come across a local isolator that has been linked out for a motor but still can be isolated upstream. Trying to get my head around emergency switching and if a local isolator is the means of it. I always thought it was just e-stops where used for emergency switching. Guess my question is is it a big no no that’s this has been done? The isolator is getting replaced when the parts are in. 


cheers guys

Emergency switching for such things as motors and machines where a danger is to be prevented or removed, used to need a single simple action, such as bashing a red coloured emergency stop button which would latch in the OFF position. This could be easily done with a hand.


I have noticed that Reg. 537.3.3.5 under the heading of DEVICES FOR EMERGENCY SWITCHING OFF, mentions handles and push buttons, coloured RED with a YELLOW background. So things appear to have changed, but not for the better I say.


Years ago if somebody's clothing was caught in a moving part and they were being dragged into the gears of a machine you could run up to a red mushroom head push button bash it and it would stop the machine. Now with a handle you have to undertake TWO actions. 1. Grab the handle and work out which way to rotate it, then 2. Rotate it to turn off the supply.

This may introduce a delay in stopping the machine or removing the danger in  a panic.


Edit. I have just found Reg. 465.3 which does require ONE SINGLE ACTION  ONLY  FOR EMERGENCY SWITCHING TO REMOVE AN UNEXPECTED DANGER.


537.3.3.3 prohibits the use of plugs and sockets for emergency switching off, so the spirit of "one simple single action" lives on.


Table 537.4 lists things that can be used as emergency switches.


Z.


 

MrJack96:

Hi guys I’ve come across a local isolator that has been linked out for a motor but still can be isolated upstream. Trying to get my head around emergency switching and if a local isolator is the means of it. I always thought it was just e-stops where used for emergency switching. Guess my question is is it a big no no that’s this has been done? The isolator is getting replaced when the parts are in. 


cheers guys

Emergency switching for such things as motors and machines where a danger is to be prevented or removed, used to need a single simple action, such as bashing a red coloured emergency stop button which would latch in the OFF position. This could be easily done with a hand.


I have noticed that Reg. 537.3.3.5 under the heading of DEVICES FOR EMERGENCY SWITCHING OFF, mentions handles and push buttons, coloured RED with a YELLOW background. So things appear to have changed, but not for the better I say.


Years ago if somebody's clothing was caught in a moving part and they were being dragged into the gears of a machine you could run up to a red mushroom head push button bash it and it would stop the machine. Now with a handle you have to undertake TWO actions. 1. Grab the handle and work out which way to rotate it, then 2. Rotate it to turn off the supply.

This may introduce a delay in stopping the machine or removing the danger in  a panic.


Edit. I have just found Reg. 465.3 which does require ONE SINGLE ACTION  ONLY  FOR EMERGENCY SWITCHING TO REMOVE AN UNEXPECTED DANGER.


537.3.3.3 prohibits the use of plugs and sockets for emergency switching off, so the spirit of "one simple single action" lives on.


Table 537.4 lists things that can be used as emergency switches.


Z.