How far must a CAT II source be from a CAT III source?

In electrical safety practices, the categorization of equipment and sources is crucial in minimizing risk during electrical measurement and maintenance. A CAT II source refers to equipment connected to a single phase of a low-voltage distribution system while a CAT III source pertains to equipment connected to the distribution panel or devices that are directly linked to the power distribution system.

The requirement for a specific distance between CAT II and CAT III sources stems from the need to mitigate the risk of electrical shock and reduce potential surges that could affect lower category devices. Keeping a minimum distance of 10 meters allows for a buffer zone that helps ensure that potential overvoltages or electrical faults in the CAT III environment do not impact the operation or safety of CAT II devices or personnel working with them.

This practice is especially significant in industrial settings where CAT III sources might experience higher levels of transients that could compromise the integrity of CAT II devices if positioned too closely. Establishing and maintaining these distance guidelines is a key component of safe electrical practices.