Re: Grounding the fuel filler
This is from the abyc standards
Custom Marine Services, Quick Source, American Boat And Yacht Council, Electrical Standards And Recommended Practices For Small Craft
E-9.21 DC GROUNDING AND BONDING
E-9.21.1 DC Grounding - If a DC grounding system is installed, the DC grounding conductor shall be used to connect metallic non-current carrying parts of those direct current devices identified in E-9.14.3 to the engine negative terminal or its bus for the purpose of minimizing stray current corrosion. See Figure 15.
NOTE: This system is the DC grounding system formerly published as ABYC E-1, Bonding of Direct Current Systems.
E-9.21.2 DC Grounding Conductor
E-9.21.2.1 A DC grounding conductor shall not be smaller than one size under that required for current carrying conductors supplying the device and not less than 16 AWG. See Figure 15 and Figure 16.
E-9.21.2.2 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:
E-9.21.2.2.1 The DC grounding conductor shall be routed together with the current carrying conductors as a third wire;
E-9.21.2.2.2 The DC grounding conductor shall be routed as a separate conductor.
E-9.21.2.3 The DC grounding conductor shall be connected to a DC grounding bus in accordance with E-9.21.5.
E-9.21.2.4 Connections - DC grounding conductor connections shall be made in accordance with E-9.17.12.
E-9.21.5 DC Grounding Bus
E-9.21.5.1 The DC grounding bus shall be connected directly to the engine negative terminal or the DC main negative bus.
E-9.21.5.2 The DC grounding bus serving more than one electrical device shall comply with E-9.21.2 for the largest device, and shall be manufactured and installed in accordance with the following:
E-9.21.5.2.1 If the DC grounding bus is fabricated from copper or bronze strip, it shall have a thickness not less than 1/32 inch (0.8mm) and a width of not less than 1/2 inch (13mm); and
E-9.21.5.2.1.1 shall be drilled and tapped providing its thickness ensures no less than three full threads of engagement for the terminal screws; or
E-9.21.5.2.1.2 shall be through-drilled, and the connections made with machine screws and locknuts.
NOTE: Copper pipe may be used providing its wall thickness is sufficient for the pipe to be drilled and tapped as required above.
E-9.21.5.2.2 Copper braid shall not be used.
E-9.21.6 Combined DC Grounding and Bonding Systems - The DC grounding conductors may be combined with the following systems providing all the requirements with respect to conductor size are met for each system. See Figure 15, Figure 16 and Figure 17.
E-9.21.6.1 Lightning Protection - See ABYC E-4, Lightning Protection.
E-9.21.6.2 Cathodic Bonding - See ABYC E-2, Cathodic Protection.
E-9.21.6.3 Static Electricity Grounding - See E-9.14.4, ABYC H-24, Gasoline Fuel Systems, and ABYC H-33, Diesel Fuel Systems.
E-9.21.7 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.
E-9.21.8 Coaxial Cables and Conduit - The metallic braid of coaxial cables and metal conduit used for radio interference, or any form of radio shielding or armoring, shall be connected to earth ground with an insulated stranded copper conductor.
TABLE III - CIRCUIT BREAKER MINIMUM AMPERE INTERRUPTING CAPACITY
