No maintenance going on here. Sounds like a cable failure. See the story.

The plumber’s snake was found in the 5kV transformer. No injuries. Basic arc flash training and electrical safety training should be required in all corporate training programs. Click here to read the news article.

These happen. If workers are present they must be protected by some means. ConEd uses arc rated clothing (ASTM F1506) and rubber gloves with leather protectors to start and arc flash blankets (ASTM F2676) in some cases. They use NESC electrical safety training for their arc flash training See ArcWear.com for standard info. Click here [...]

Note: This is my opinion with ONLY the news article information. Looks like something I had thought COULD happen has happened. Arc flash in manhole, blows off cover and hits someone. Prevention of arc flash can help save public too. Click here to read the news article.

Another arc flash in a network system. Hawaiian Electric has two workers injured. Most likely they were in arc rated clothing since “one of the men was initially deemed to be in critical condition but was upgraded to serious condition shortly after his arrival at the hospital.” Following the requirements of the NESC and OSHA [...]

Here is what methane buildup in manholes can do. Arc flash is about the same but more power from a burn perspective on those in the hole from arc plasma in some cases. Click here to see the video. It is one of my YouTube Favorites.

BC Hydro was an early adopter of arc rated clothing for all arc flash exposed utility workers. This network system arc flash blew off a manhole cover (~90lbs/40kg). Moving to flame resistant clothing stops clothing ignitons and dramatically reduces injuries. The second report says there are second and third degree burns and all workers are [...]

This arc flash/blast was caught on video in London England. No one hurt but the blast is fairly significant. No worker’s present. Interesting the advertisement before the blast video story is for cotton. Not my choice for working in a manhole. Click here to see the arc flash video.

My bet from reading this is that they had an arc flash. They were probably wearing arc flash clothing (ConEd has rules on this) because the burns for ignited clothing are usually critical not just serious. NESC requires using protective clothing in these situations. These injuries can sometimes be prevented with arc flash blankets meeting [...]

Underground networks in our larger cities have the most fault current of all the electrical systems other than possibly a smelter. These networks must be worked on and in by highly qualified persons but there are coming new devices such as arc flash protective blankets which are tested to meet ASTM F2676 that can help [...]