quote=ron hunter]What you describe sounds entirely correct. The isolator is not an emergency stop.
If you think you might have an issue with your people doing the wrong thing you should consider re/issue of information and instruction, and maybe put a physical barrier or shroud over the isolator to prevent inadvertant use.
As an OEM machine builder, we have learnt over the years that an isolator switch can be either :-
- an isolator to cut the power supply
or
- an isolator to cut the power supply that has also been designed to act as a safety switching device
the correct way that you differentiate between the 2 is the colour of switch, as detailed in EN 60204-1.
Within EN 60204-1, clause 5.3.3 states that for an isolator switch, “it is recommended that it be coloured black or grey, (see 10.7.4 and 10.8.4)”.
Section 10.7 concerns Emergency Stops, and 10.8 Emergency Switching Off Devices. Together they allow for the isolator to be used as an emergency stop/switching device and that it must be red/yellow providing the correct switch is selected and be readily accessible.
Therefore if the switch :-
- is purely to isolate the power supply it should be black/grey
- where it has been designed to also act as a safety switching device, it must be red/yellow
Where it has been designed to act as a safety switching device, this must be documented in the Technical File.
However, I regularly see equipment incorrectly using red/yellow isolator switches, where it purely acts as an isolator and not as a safety switch. This is because the requirements laid down in EN 60204-1 do not seem to be widely known or understood.
I have even raised this during a recent training session on the Machinery Directive run by a "Notified Body" who were not aware of this, (to my horror), only for the engineer presenting to come back to me and confirm I was correct after checking during the lunch break.
Therefore in rich777's situation, where the isolator clearly is not acting as a safety device, I would first ensure that the isolator is changed to grey/black if it is not already and follow it up with instruction/training to the operators/supervisors on the colour coding of switches.