On a recent episode of "Deadliest Catch" (A Discovery Channel series about Alaska Crab fishing, airs at 5 and 8pm Pacific time) one of the vessels experienced a serious electrical failure. Apparently a breaker in the main distribution panel failed, causing total power loss which tripped the main breaker. The crew located the problem in the panel by first finding the "burning smell" then proceeded to reset the main which caused an arc flash (luckily for them behind the deadfront!).
They removed the defective (?) breaker and tehn reset the main again which held. Once they had full lighting again you could clearly see the flash damage to the panel interior.
Several things about this incident caught my attention:
1) The crew did not seem to be too aware of the real danger of standing too close to a faulted panel while resetting the main breaker. (Of course, the real issue for them was the possibility of sinking as the vessel could not move without power.) Luckily the arc flash was "small" as I'm sure that the size of the vessel's generator limited the availble fault current.
2) After restoring power there was a lot of poking around with the deadfront removed.
3) The PPE consisted of their wet raingear and fishing gloves (yikes!)
4) The panel was located in a passage directly off of the main deck, roughly 10-20 feet from the hatch, protected but still looked like it could get wet. It did not appear to be a NEMA 3R can.
5) With the stuff piled in front of it, who needs working clearance?
This episode should re-air at 5pm Pacific time on June 7th if you'd like to check it out.
Now for the questions for our experts:
1) Are there special breakers made for marine applications? The breakers appeared to be standard "H"(?) Frame types, (GE/Westinghouse) similar to those I've seen in cinema main panels.
2) Same idea in regards to panels. I would think that constant exposure to salt water mist/air would require special materials to hold up.
3) Is there some sort of equivilant to the NEC for ships?
"Deadliest Catch" is an interesting show overall, I was amazed at what those folks go through to catch some crab. The stakes are high, it is dangerous and backbreaking work, but the payoff is also high. In the first part of the series, the "King Crab" season, each crew member of the vessel catching the most crabs walked away with over $8,000 EACH for three days of fishing!