How To Wire Up My Boat

Based on the ABYC Wiring Rules. Comply and SeaBis will indicate Normal. Comply and you will not cause electrolysis. Failure to comply may void insurance.

Contact us with SeaBis Master results and we will step you through How to Wire up Your Boast so as to prevent 97% of CAUSE of marine corrosion. The remaining 3% is caused by different metals in very close proximity and can be prevented by anode/s when the vast majority cause, electrolysis (stray current) is prevented by SeaBis. 8 years free support, guarantee AND warranty.

© 2003 American Boat & Yacht Council (ABYC) Reference: E-11 

References to ABYC Wiring Rules:

ABYC Wiring Rules in italics:

The ABYC Wiring Rules are recognized by all authorities, World-wide as per-eminent, correct and legally binding.

ABYC Wiring Rules must be complied with to eliminate the cause of electrolysis (metal corrosion) otherwise your insurance may NOT be valid. If you chose not to eliminate the stray current that is the ONLY cause of electrolysis you will have no insurance from marine electrolysis or metal corrosion. The critical (paste and copy) excerpts follow and the entire ABYC Wiring Rules via a link at the end of the rules.

The ABYC Wiring Rules are accepted World-wide and form a solid base for insurance companies to accept or refuse claims for electrolysis.

The SeaBis System eliminates the CAUSE of all electrolysis and complies with ABYC. No additional coating, plating, moving parts or through hole.

ABYC references in italics:

  1. This is rock hard and definite. The Bonding or DC grounding conductor shall not be used as battery negative:

11.5.2.2. DC Grounding Systems and Bonding – A metallic hull, or the bonding and DC grounding systems, shall not be used as a return conductor. (See Figures 9A and 9 B, and Figures 10 A and 10 B, and E-11.18 DC Grounding and Bonding.)

  1. This is rock hard and definite. The DC Grounding conductor must carry no current. Battery negative carries 80% of the battery positive. So, battery negative must not be used for Grounding,

Definitions – Continued that is intentionally maintained at boat ground potential. DC grounding conductor – A normally non-current carrying conductor used to connect metallic non-current carrying parts of direct current devices to the engine negative terminal, or its bus, for the purpose of minimizing stray current corrosion.

  1. This is rock hard and definite. Battery negative must be insulated from engine and drive train:

11.16.4.2.2.3. The ungrounded battery cable shall be routed to avoid contact with any part of the engine or drive train.

  1. This is rock hard and definite. Battery negative carries 80% of battery positive current so must be insulated:

11.17.2.1. Appliances and fixed DC electrical equipment shall be designed so that the current carrying parts of the device are insulated from all exposed electrically conductive parts

  1. This is rock hard and definite. Third wire! The battery negative is not to be used as DC grounding conductor.

11.18.2.2. Routing – The DC grounding conductor shall be routed from the device to the engine negative terminal or the DC main negative bus by one of the following means: 11.18.2.2.1. The DC grounding conductor shall be routed together with the current carrying conductors as a third wire.

  1. This is rock hard and definite. The battery negative is not to be used as DC grounding conductor.

11.18.2.2.2. The DC grounding conductor shall be routed as a separate conductor.

  1. Radio (HF SSB) Ground Plate. We fit a special capacitor ( 0.47 micro farad, BI-POLAR (NOT electrolytic), rated at 2,000 volts – try Kermit), or battery switch to DC negative, in series with the Tuner / Transceiver connection to the (metal) hull to stop battery negative on the Tuner / Transceiver metal body causing electrolysis. The capacitor allows the Radio to work correctly (pass AC while stopping DC).

11.18.2.7. Radio Ground Plate – If the radio ground plate is connected to the engine negative terminal, the connecting conductor shall meet the requirements of ABYC E-4, Lightning Protection, since a radio ground plate may also function as a lightning ground plate.

8:  In a life time of defeating corrosion, I have never known shore (AC) power to be a cause of stray current that causes electrolysis.  IF shore power were to generate DC (battery power) every appliance powered by AC would incinerate in a few minutes.  However: The shore earth connection should be via a proven Isolating transformer (not Auto-Transformer) to the body of the boat.  So, there is no DC path from shore mains earth to the body of the boat but the safety function of mains earth is maintained. SeaBis will detect and indicate current from the earth – To test shore power for stray current: First, with shore unplugged, get entire boat to Normal then plug in the shore. SeaBis Master will immediately indicate either no stray current or otherwise.

9:  Natural inter-metal voltage differences than would otherwise cause galvanic corrosion can be vastly reduced by use of anodes and Bonding.  Bonding is small wire around the inside of the hull connected to anode conductive mounting bolts that themselves make a good contact to the metal (hull/prop shaft/etcetera).  So, the natural inter-metal voltage differences are reduced and the anodes are sacrificed rather than your metal.

Link to ABYC Wiring Rules. © 2003 American Boat & Yacht Council (ABYC) Reference: E-11

The same physics as form the basis for these Wiring Rules were true when I first went to sea in 1964 as they are today.

Glen Bishop of SeaBis
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Australia  61 then (0)417 878 773 or Skype: seabis
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