thread238-290829

[joymon]

thread238-290829
Any thoughts on why the NFPA 70 495.70 mandates a solidly grounded 4W connection for Electrode type boilers higher than 1000V. Any thoughts on why the NFPA 70 forbids a 3W connection from an impedance grounded system; one would think at higher voltages the impedance grounding would reduce the ground fault currents, thereby inherently making the system safer.

 

[davidbeach]

A hard fault, quickly cleared, could present a much lower hazard than one that just sits there.

I’ll see your silver lining and raise you two black clouds. - Protection Operations