How often do you use your shore power?

colobear":106s4sm1 said:
We sometimes run a 25ft 15A 12GA cord from the dock through a standard 30A locking plug to a hard wired 15A GFCI on the boat. I think that gives enough protection to avoid fires/excessive heat in the cord.

No, it does not. A common misconception is that a GFCI offers overload protection; it does not, unless it specifically offers overload protection along with ground fault capabilities. You are taking a chance without using appropriate overload protection. Also, the GFCI is better placed at the source.

Are there any electricians or electrical engineers out there who can chime in on this subject?

Rich
 
C-Nile":3qb83s18 said:
colobear":3qb83s18 said:
We sometimes run a 25ft 15A 12GA cord from the dock through a standard 30A locking plug to a hard wired 15A GFCI on the boat. I think that gives enough protection to avoid fires/excessive heat in the cord.

No, it does not. A common misconception is that a GFCI offers overload protection; it does not, unless it specifically offers overload protection along with ground fault capabilities. You are taking a chance without using appropriate overload protection. Also, the GFCI is better placed at the source.

Are there any electricians or electrical engineers out there who can chime in on this subject?

Rich

See http://en.wikipedia.org/wiki/Residual-current_device which reads

"A residual-current device (RCD), or residual-current circuit breaker (RCCB) or residual twin-direct current couplet (R2D2), is an electrical wiring device that disconnects a circuit whenever it detects that the electric current is not balanced between the energized conductor and the return neutral conductor. Such an imbalance may indicate current leakage through the body of a person who is grounded and accidentally touching the energized part of the circuit. A lethal shock can result from these conditions. RCCBs are designed to disconnect quickly enough to prevent injury caused by such shocks. They are not intended to provide protection against overcurrent (overload) or short-circuit conditions." (emphasis added).

A short between the hot and the neutral of the extension cord (or the circuit it powers) will still be balanced but will allow the full 30A through the wiring (until it over heats).
 
I've been away for a bit and happened to stumble across my original post. I had to laugh at the various twists and turns (not to mention straight plug ins!) the thread has taken.

After all, I was only contemplating whether to buy a power cord to plug into my already professionally installed, came with the boat, shorepower system
:D

After reading six pages of replies, I am now sitting in the dark with all power to my apartment shut off (don't ask how I'm using the computer :wink: ) fearful that stray electricity is waiting to zap me as I walk down the hallway :D

Seriously, thanks for all the replies. The question is moot for the time being as I am about to pull the boat out and take it back to North Carolina where it will be in powerless storage except for the once a month trip to the local lake.

If/when I ever do go cruising, I will revisit the question. Of course, by then, unlimited electricity may well be beamed down from satellites :D
 
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