BS EN 60204-1 Help required re : Earth loop testing of machinery

[markymark31]

Hi Guys,

The 17th edition gives you a table of circuit breakers and their maximum allowed Zs, however as the 17th edition does not cover "machinery", we have just started working with BS EN 60204-1 "Safety of machinery - Electrical equipment of machines - Part 1 General requirements", and this standard does not have a similar table.

Annex A.2 does reference Zs / fault currents / voltages etc. but nothing that I can really get my head around.

Does anyone have any practical examples of how I can show my test readings and document the fact that these do (or don't) meet the requirements of this standard ?

Thank you,

Mark.

 

[johnboy6083]

The Zs values for OCPD's are listed in BS7671, however they are not part of that standard. Your mcbs in your machines still have to comply, or else disconnection times will not be met. As for the appropriate times?

 

[markymark31]

Thanks for the reply, disconnection times is the easy bit, these are stated in 60204-1. So is it the MCB standard itself that states the max Zs (60898 etc. ?) everywhere else I look it keeps referring me back to BS7671 ?