Has anyone come across specific standards on the max/min height of an E-Stop position or the max reach horizontally over the top of equipment to an E-Stop ?

ISO 13850 does not mention any such limits.

We have a major US customer who specifies in their RFQ such detail. Checking the equipment we manufacture, the E-Stops are are all 20mm inside each of the limits quoted for max/min height and max reach.

When I discussed this with our Engineering Director, his reaction was "thats lucky because it wasn't planned".

Apart from deciding if the E-Stops are correctly positioned in the Risk Assessment, has anyone come across any specified max/min positions for an E-Stop ?

zimmy,
I doubt that BS7671 would be relevant to machinery as it is specifically excluded from the scope of the regulations.

I had not answered the OP as I could not think of any.
There may be some buried in the ergonomics standards?
There is another that seems to ring bells, but I can't remember enough detail to give a valid answer.