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Posted By: Eclectic Marine Electrical Safety - 01/16/16 03:52 AM
Hi folks, "Heard" about an interesting possible electrical safety hazard today. This was at a shipyard (saltwater) where work is performed on vessels moored at a pier. The shore power for the vessels is 480. This is supplied by a Square D SE series breaker, 1200 Amp. This in turn fed multiple sub panels. Problems started with recurrent ground fault trips on this main breaker. This happened during unusually high tides or very rainy and windy weather. During the high tides, stainless boxes with ocal conduit were submerged. To try and troubleshoot the problem, 2 electricians were dispatched out in an aluminum skiff with no PPE in pouring down rain conditions. They were to open up the boxes and inspect them after the tide had receded. All circuits were still energized. Their shop safety rep noticed what was about to transpire and lodged an immediate complaint. His reasoning was that if another ground fault were to happen while one of these workers was touching the stainless box, there was a chance of electrocution. (All paths to ground). He felt that the breaker reliability had been compromised, and even if it had not, injury could happen before the ground fault protection took effect. One worker argued that if there were no connections in the boxes (that they were used as pull boxes), there should be no hazard. Well, long story short, the safety guy prevailed, after reminding management/supervisory staff of certain regulatory/liability issues. So, anyone have thoughts on this?
Posted By: gfretwell Re: Marine Electrical Safety - 01/16/16 08:06 AM
I assume this was GFPE (30ma) and that will give you quite a jolt in salt water.
I am not sure I would let anyone near that equipment while it was energized at all. The idea that these "pull boxes" had no connection to the conductors ignores the fact that they were there looking for a ground fault.
A plastic boat would be better.
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