Incident Report

Subject:                     Electrical Safety Week

Date of Email reporting Incident:   Wed 07/05/2008

Report Detail:

Close call.

This is an example of why we wear flash suits to operate breakers these days. This incident took 30 sec. to clear. That would seem like an eternity if you are there. The attached safety alert message is the result of a 480 Volt circuit breaker fault during an attempt to open the breaker at an unknown facility in Missouri . Pictures are worth a thousand words, and these photos should make quite impression.  Proper operating procedure, appropriate electrical safety training, PPE, engineering equipment design and device settings are very important safe electrical system operation. Standing directly in front of a breaker cubicle (or in the immediate vicinity) during the breaker operation is not a good idea. If equipment does not perform as expected (failure of the breaker to trip on manual trip initiation), repetitive attempts are also not a good idea. Although this electrical fault condition actively continued for 30 seconds before the fault burned clear, never attempt to manually open an up-stream circuit breaker during an on-going electrical fault condition.  A description of the incident follows in the employee's own words : 

    "Here are pictures of my close call with a 480 Volt 1200 Amp Main breaker that I was trying to trip out. On the first two attempts of pushing the trip button while standing off on the hinged side of the door nothing happened. On the third try it exploded and kept exploding for about thirty seconds. Instead of instantly tripping the upstream 4160 Volt Breaker, the buss bar connected to the top of the breaker had blown and melted open. Leaving the incoming feeders still energized because the trip relay on the 4160 Volt breaker had an incorrect trip set point. When the fire ball & gouging stopped I was able to crawl under the smoke and with my flash light try to find my partner who was standing ten feet away waiting for me to rack out the 480 Volt breaker so he could rack out the up stream 4160 Volt breaker.  The fire ball was shooting directly at him and he was sprayed with sparks and hot molten metal. Thank God he was far enough away and was able to react quick enough to escape through the back door of the MCC. We lost sight of each other through the fire balls and thought the worst. I can't stress safety enough, had I been standing on the other side of the door or If Chris had walked toward me to see why it wasn't tripping. We would have both been seriously injured or killed"
    "Having had this happen to both of us before we always expect the worst when doing switching and take every possible precaution to make sure everyone involved is out of harms way because you just never know when a Breaker may malfunction and you may never get a second chance. After we came back from first aid and came out of shock we put on a clean pair of shorts and called home. We left work early that day and couldn't wait to get home to see our families. I don't recall ever being so happy to wrap my arms around Debby and the kids and tell them how much I love them.  We don't go to work every day thinking we might not make it home that night but we do spend a lot of time thinking about everything else but the job at hand. This has been a good reminder for me and hopefully all of you.....One second of complacency could result in a life time pain and suffering. We must all take the time to stop and think what could go wrong. Lets not only think of ourselves but of all the people that would be affected by any of us being injured"

                                                                                        Anonymous Writer....

Additional Documentation:

Close Call Electrical Incident