Correct grounding and bonding

[goboatingnow]

It is just ignorance and stupidity, and not a lack of codes.

well actually it is a lack of codes.....

[GordMay]

Originally Posted by bazzer

What's RCD?

RCD = Recreational Craft Directive (European Standard)
or
RCD = Residual Current Device (30 mA trip)

RCBO = Residual Current Breakers with Overcurrent protection
GFCI = Ground Fault Circuit Interruptor (5mA trip)
ELCI = Equipment Leakage Circuit Interrupter (30mA trip)

[Richard_W]

Originally Posted by goboatingnow

well , thats what you get away with using 110Vac, 220-240Vac and you-all be dead guys. ( which is why were covered in RCDs)

I worked with both 240V AC in Europe and 120V AC in US/Canada. I have to tell you the 120V AC stings more here than one in Europe. It has to do with V*A=W equation ... less V more A at the same W ... and the A (current) is what kills.

[goboatingnow]

RCD = Residual Current Device (30 mA trip)


European RCDs are available in a wide variety of trip currents, thats just the standard domestic and general usage trip as specified by certain codes for all house ( all boat) uses.

Dave

[goboatingnow]

I worked with both 240V AC in Europe and 120V AC in US/Canada. I have to tell you the 120V AC stings more here than one in Europe. It has to do with V*A=W equation ... less V more A at the same W ... and the A (current) is what kills.

Sorry , that may be a perception, but its technical nonsense, remember its a V=IR issue ( twice the voltage for a given resistance , twice the current!, nor am I aware that the resistance of a US human differs much then elsewhere !) , 110VAC is the mandated voltage on building sites here, 230Vac isnt allowed, theres a very valid reason.

Dave

[Richard_W]

well actually it is a lack of codes.....

There are codes for that ...

110VAC is the mandated voltage on building sites here, 230Vac isnt allowed, theres a very valid reason.

building sites ... where ... sorry you lost me

I was talking about single phase 220-240V AC in Europe ... it is used in most of the Europe ... at least was when I was there.

[bazzer]

Originally Posted by Richard_W

There are codes for that ...

The requirement for insurance is that my boat follows the ABYC codes which I read here say to connect the AC ground and the DC ground together, but as several have pointed out it might be a unsafe practice so what the hell am I to do? I'm between a bit of a rock and a hard place on this one!

[Richard_W]

Originally Posted by bazzer

The requirement for insurance is that my boat follows the ABYC codes which I read here say to connect the AC ground and the DC ground together, but as several have pointed out it might be a unsafe practice so what the hell am I to do? I'm between a bit of a rock and a hard place on this one!

Connecting both grounds, AC and DC, is recommended by ABYC for human safety. It might not be the best approach for some devices, interferences, corrosion, etc.

To minimize the negatives make sure the boat installations are done correctly and well, boat is equipped with galvanic isolator (or isolating transformer), and that the dock/marina is GFCI protected if you plan to use shore power.

[donradcliffe]

Connecting the grounds may improve safety for people IN the boat, but it can be fatal for people swimming in fresh water around the boat.

The last California building code I looked at discouraged RCD's for dock power--the reason given was too many false trips. There were moves to change this--maybe someone with access to the latest code can see whether they have changed their minds.

[Richard_W]

Originally Posted by donradcliffe

Connecting the grounds may improve safety for people IN the boat, but it can be fatal for people swimming in fresh water around the boat.

I think it is both ... to protect people in water and in boat. The ABYC E-11 was enacted to prevent well publicized cases of in-water electrocution by faulty and/or not properly grounded boat installations.

Look at this link provided by boatpoker: documents.html ... download/look at the document #11. There is a good illustration how the stray current caused by faulty installation or device failure where AC enters DC circuits is dissipated via AC/DC grounding buses connection to the AC ground (earth) rather than via water (and swimmer) to shore.

[Richard_W]

Originally Posted by bazzer

The requirement for insurance is that my boat follows the ABYC codes which I read here say to connect the AC ground and the DC ground together, but as several have pointed out it might be a unsafe practice so what the hell am I to do? I'm between a bit of a rock and a hard place on this one!

On the second thought ... scrap this topic and call in the real expert like the guy whose website boatpoker referenced. This is TOO SERIOUS to mess around with.

[sailorboy1]

I'm going to stay out of all advise, but in case no one has said this on the thread; West Marine has a good article on bonding/grounding in their advise section on line.

[senormechanico]

Originally Posted by goboatingnow

Sorry , that may be a perception, but its technical nonsense, remember its a V=IR issue ( twice the voltage for a given resistance , twice the current!, nor am I aware that the resistance of a US human differs much then elsewhere !) , 110VAC is the mandated voltage on building sites here, 230Vac isnt allowed, theres a very valid reason.

Dave

+1 and glad you corrected it.
How can a person's resistance automatically go up or down between continent's electrical delivery systems ?

Steve

[Lake-Effect]

ABYC released this online presentation on Electric Shock Drowning last year, given by Kevin Ritz, a guy who has devoted years to studying ESD... after losing his son to just such an incident.
[edit - this is the same kid mentioned in boat-poker's link]

this online presentation

If you're at all concerned about this issue, spend the hour and watch it. It covers the causes, effects and how to detect faults.

Originally Posted by donradcliffe

Connecting the grounds may improve safety for people IN the boat, but it can be fatal for people swimming in fresh water around the boat.

The last California building code I looked at discouraged RCD's for dock power--the reason given was too many false trips. There were moves to change this--maybe someone with access to the latest code can see whether they have changed their minds.

Electric Shock Drowning is essentially nonexistent in Europe, because for the last 30 or so years they've mandated such protection for all shore-power outlets. They've been able to select a trip current level that provides protection without nuisance trips. In the presentation, I believe it's mentioned that North American standards bodies are proceeding towards a similar standard.

Grounding the boat to shorepower via a galvanic isolater, as per ABYC E-11, is sensible.