galvanic isolators
Greets:
Had a long discussion with ProMariner yesterday sorting out some
issues with the AC electrical system. I'm posting the following
information simply to document the conversation, the issues and the
resolution.
The issue that I encountered over the winter was that my GI died,
combined with the starboard and port circuits going off line. Now the
configuration is as follows: Starboard, 3 CGFI receptacles, port, 1
CGFI receptacle. All dead. Putting a meter on them showed power and
ground reversed, not good.
Over the winter I installed 2 ProMariner GI's and both burned out
within a day or two. Same reads on the meter. Continuity checks showed
no issues. Drove me nuts. So pulled the GI off line, disconnected the
starboard circuit, ground hot and neutral and ran the remainder of the
winter on one receptacle on port side. Standard receptacle no CGFI.
All worked fine.
In the spring I can back to the boat after a short spell at home,
thought I passed a kidney stone which turned out to be a bladder
infection. Good thing, I would not want to pass a stone the
States...med costs are seriously expensive. I was good to go again.
Came back to the boat which now had a chance to dry out as humidity
was the biggest issue to content with during the winter and
immediately went to work on the AC system. Before I left I
disconnected all AC circuits and wires all nicely labelled. To get a
base line I brought up one circuit and one receptacle at a time, I was
gonna lick this problem once and for all.
To my surprise everything came up as it should. Scratched my head and
left it alone and made some coffee. The difference this time was that
I used the percolator as never tested it that the former PO left me
and raved about. Les was right it made dam good coffee the only thing
i noticed is that it kicked out quite a bit of steam. Shortly after
the coffee was done peculating I left the unit plugged in to see if it
had an auto off. Before I could find out, I heard that dreaded click
of the CGFI's going off line. All circuits down again and the tester
showed the same symptoms, ground and power reversed. Not good.
Finished my coffee and spend the remainder of the morning trying to
find the short. Turns out there is a run of wire under the rear
bulkhead on the floor pan that runs the starboard wires to port where
the electrical panel is located. These wires are rather tight and the
entry and exit holes are rather sharp, particularly the exit hole. OK
this is where the short is occurring. The wires have chaffed just
enough that when its wet, the ground and hot will interfere with each
other. Wow...that only took six months to find. As an aside talked to
Walter at Ace Hardware in town and kept him informed as three other
boaters were experiencing the same issues. Everyone was scratching
their heads trying to find intermittent wire breaks that were not
showing up on continuity testing. So went back to the old standby, of
removing all wires from the starboard circuit leaving only the port
receptacle. (there is one more issue to address and that is to find
where the starboard circuit is bleeding into the port circuit but that
will be address when I rewire the AC system completely) Also talked to
Les a lot about this issue, he was so helpful, but the AC side of the
boat was addressed by the previous PO, so we were both scratching our
heads an non of this made any sense at all.
So the point of the story is this. Called ProMariner yesterday
(starting to plan out all needed issues for when I return) as I did
not want to install another GI that did not have some form of
protection against power reversal or current overage. They make
battery chargers like this why not GI's as these things arnt cheap.
Turns out they do. There monitored GI is the only product they sell
that actually has protective circuitry against power issues and as
ABYC no longer requires a monitored GI system, they are stuck with
inventory I guess. So in conversation westmarine model no. 8648958 was
made available for 200. This is the Promariner ProSafe1 Single AC Line
System (Single 30A shore cord) Monitored ProSafe 1 Galvanic Isolator &
AC Ground Wire System that West sells for 400. The design circuitry is
such that if there is a power overage or reversal of power the units
fan starts to spin and whine like crazy till you take the system off
line. Their battery chargers are already protected against this.
My only question is why are not all units designed like this as it
could have saved me a 3 stage 3 bank battery charger which really was
very good despite its age and a relatively new battery. Having worked
with computer hardware the costs are incremental and you would think
that a short in the AC wiring system is a rather common fault. The
lesson here was that not all GI units are protected against shorted
wiring systems but there is a product available that can protect you
from needless downtime.
Best regards
/ch