Are all Galvanic Isolators the same? Are the GUEST Galvanic Isolators from
West Marine as good as any others? I need to install a 30 AMP Galvanic
Isolator.



Is it true if I disconnect the dock power from the boat when I am not their,
I do not need one?



Thank you

Disconnecting the shorepower eliminates _that_ source of problems; ie.
the isolator won't have anything to do unless you're plugged into the
dock. However, all the time you _are_ plugged into the dock, the
potential exists for galvanic problems over the ground wire and the
isolator can provide some protection.

I don't know a lot of alternative manufactueres. Guest seems to make
adequet products. I have owned one for 4 years and it appears to do its
job, although it has a relay that clicks every 3 or 4 seconds -
according to their product support whom I called immediately after
installing it, "this is normal". So far, so good anyway.

Get an isolator with indicator lights that will tell you if it gets
blown and if it gets overridden by too much voltage on the ground wire.
Mine shows "Unit Failed" or "Passing ground current now". Without a
"Unit Failed" light, you have no idea if the thing has given up its
little life in the line of duty - leaving you without any protection.
Ideally I'd like to see whether it has passed any ground current at all
in the interval since the last time I reset it, but I don't know if that
option is even offered in their products. Since I don't spend 24 hours a
day gazing at the LED's, that would help me know if there is a problem
brewing.

The sensing circuit in the Guest uses 12VDC, so in order for the
indicator lights to work, you must provide a 12volt supply and ground to
the unit. The spec sheet says it will still provide full protection
without the sensing circuit hooked up. The LED draws a small amount of
12vdc power which I've never bothered to measure - hasn't ever been a
problem. If you turn off the 12vdc master switch when you leave the
boat, it won't draw any current at all, and will continue to protect the
boat.

From what I understand, galvanic isolators are a good investment if you
get a unit that provides enough info to let you know it's doing its job.

Rufus



SBC wrote:
Are all Galvanic Isolators the same? Are the GUEST Galvanic Isolators from
West Marine as good as any others? I need to install a 30 AMP Galvanic
Isolator.



Is it true if I disconnect the dock power from the boat when I am not their,
I do not need one?



Thank you