T-Pain Is On A Boat: Re: [Electric Boats] Grounding an electric conversion in fresh water

Friday, August 1, 2014

Re: [Electric Boats] Grounding an electric conversion in fresh water

I know this. And I want to try to remedy this situation before I
launch.
However, as I detailed below, the AC system on my boat amounts to little
more than a glorified extension cord.
It is on the port, aft side of my boat, where no DC wiring exists, in a
ockpit locker which has no through hulls, metal or otherwise.
From the shore-power plug, it is a 6' straight run of cable to the AC
panel.
From the AC main panel, it is less than a foot of wiring to the GFCI
outlet over the galley.
From there, it is a secured heavy-duty extension cord that connects to
the isolated-output charger.
Chances of any of the AC wiring contacting any DC-wiring or
water-connected metal are extremely low.
The non-GFCI-protected AC wiring on my boat amounts to under 7' in
length and is properly secured and has no exposed terminals that could
be contacted or shorted in the locker. And even then, there is no way
for anything in that locker to contact anything else that would be
connected to the water.

So while I don't deny the hypothetical danger I am placing on
hypothetical swimmers in our marina, the actual risk due to my boat is
very small and will soon shrink to as near nil as I can make it. As you
say, the risk is present "in the event of a fault". For the simple
shore-power setup I have had until now, I think the risk from my boat to
the waters in my marina is very small. However, since I plan to be able
to run my electric propulsion via a portable generator plugged into the
shore-power plug, I feel I need to have a proper AC ground in the boat
before I launch. And this is why I am asking the forum here. One thing
is clear to me, however. I am not alone in not understanding boat
grounding systems. And once you remove the "engine mass" as in an
electric boat, that understanding drops even more. Put that boat in
freshwater and the understanding drops even further. ABYC is full of
"can be" and "may be" language, and has surprisingly little "must be"
directives in this regard so even when looking up the authoritative
info, one does not find certainty. So, I am seeking advice here, from
my vendor (a certified ABYC electrician) and also from a couple of other
sources (both marine electricians). I generally dislike doing things
"just because that's the way it's done". So even after I have the
"right way" presented to me, I will have to mull it over and think on it
until I come to grips with why it's the right way.

Cheers,

/Jason

On 2014-08-01 10:04, Chris Hudson clh5_98@yahoo.com [electricboats]
wrote:
> Considering you are in fresh water you are putting people at great
> risk with your 120VAC ground left floating at the dock. If for some
> reason you lose your ground connection to the dock, any person could
> become that connection in the event of a fault.
>
> Chris
>
> Sent from myPhone
>
> On Jul 31, 2014, at 16:33, "boat_works@yahoo.com [electricboats]"
> <electricboats@yahoogroups.com> wrote:
>
>> Here's my interpretation of the relevant ABYC standards.
>>
>> E-11.16.1 Allows, but does not require, a DC grounding system to be
>> installed.
>>
>> E.11.16.25 If a DC grounding system is installed, it is allowed to
>> be, but not required to be, combined with the lightning protection,
>> cathodic bonding, and static electricity grounding systems.
>>
>> E.11.5.4.7 Requires the AC system grounding bus to be connected to
>> either the engine negative bus, or the DC main negative bus.
>>
>> E.11.5.7.4 Allows, but does not require, the negative side of the DC
>> system to be connected to be connected to ground.
>>
>> TE-30 Requires that the propulsion electrical system remain isolated
>> from the boat's grounding system.
>>
>> -Tom
>
>
>
> Links:
> ------
> [1]
> https://groups.yahoo.com/neo/groups/electricboats/conversations/messages/25860;_ylc=X3oDMTJxdGxodWs0BF9TAzk3MzU5NzE0BGdycElkAzUyMTQzODIEZ3Jwc3BJZAMxNzA1ODg0MDkwBG1zZ0lkAzI1ODYwBHNlYwNmdHIEc2xrA3JwbHkEc3RpbWUDMTQwNjkwMTg4Mw--?act=reply&messageNum=25860
> [2]
> https://groups.yahoo.com/neo/groups/electricboats/conversations/newtopic;_ylc=X3oDMTJlNHFtb2NnBF9TAzk3MzU5NzE0BGdycElkAzUyMTQzODIEZ3Jwc3BJZAMxNzA1ODg0MDkwBHNlYwNmdHIEc2xrA250cGMEc3RpbWUDMTQwNjkwMTg4Mw--
> [3]
> https://groups.yahoo.com/neo/groups/electricboats/conversations/topics/25855;_ylc=X3oDMTM2aG1wNHViBF9TAzk3MzU5NzE0BGdycElkAzUyMTQzODIEZ3Jwc3BJZAMxNzA1ODg0MDkwBG1zZ0lkAzI1ODYwBHNlYwNmdHIEc2xrA3Z0cGMEc3RpbWUDMTQwNjkwMTg4MwR0cGNJZAMyNTg1NQ--
> [4]
> https://groups.yahoo.com/neo/groups/electricboats/info;_ylc=X3oDMTJlOWVvMGF0BF9TAzk3MzU5NzE0BGdycElkAzUyMTQzODIEZ3Jwc3BJZAMxNzA1ODg0MDkwBHNlYwN2dGwEc2xrA3ZnaHAEc3RpbWUDMTQwNjkwMTg4Mw--
> [5]
> https://groups.yahoo.com/neo/groups/electricboats/members/all;_ylc=X3oDMTJmMGZqbGtlBF9TAzk3MzU5NzE0BGdycElkAzUyMTQzODIEZ3Jwc3BJZAMxNzA1ODg0MDkwBHNlYwN2dGwEc2xrA3ZtYnJzBHN0aW1lAzE0MDY5MDE4ODM-
> [6]
> https://groups.yahoo.com/neo;_ylc=X3oDMTJkc2VyYXQ2BF9TAzk3NDc2NTkwBGdycElkAzUyMTQzODIEZ3Jwc3BJZAMxNzA1ODg0MDkwBHNlYwNmdHIEc2xrA2dmcARzdGltZQMxNDA2OTAxODgz
> [7] https://info.yahoo.com/privacy/us/yahoo/groups/details.html
> [8] https://info.yahoo.com/legal/us/yahoo/utos/terms/

--
Jason Taylor
--
S/V Fugu
1978 Beneteau First 30
Electroprop PM-20