Overdutied Protective Devices and Catastrophic Failures

People seem to love to watch videos of electrical explosions. One type of failure is when a protective device is applied beyond its interrupting rating and catastrophically fails (explodes) when it has to interrupt a short circuit. Although this does not happen for every overdutied device, it could happen. That is the main reason for performing a short circuit study – to identify these types of deficiencies so they can be corrected.

So with that intro, here is this week’s question.

Have you/clients ever had an overcurrent device catastrophically fail when it interrupted a fault?


NFPA 70E – Qualified Workers

“Raise your right hand”  Pretty intimidating words – especially if they are said in a court room and the trial is about an injury or death.  –  and you are on the wrong side of what happened.  Let’s face it in the litigious society that we have in the United States, it seems anytime there is an accident where there is a significant economic loss, personal injury or worse – someone died, there will almost certainly be legal actions. Continue reading

Electric Shock – It CAN Happen to Anyone – Like Me!

Electric shock happens to more people than they care to admit. In almost every NFPA 70E / electrical safety training class that I conduct, I ask the group “how many of you have NEVER experienced an electric shock.” I have yet to see a hand go up. In today’s “Modern World” electricity is part of daily life and as a consequence, an electric shock can happen to anyone – Including Me! Continue reading