Grounding Wind Generator Systems on a Vessel
Grounding of wind generators on board a boat is critical part of a safe and reliable installation. The recommendations listed below is for informational purposes and a qualified certified marine electrician should become involved in the design and installation of the wind generator grounding system.
What is a ships ground? Click here for more information.
Wind generators and their related mast must be grounded to the ships ground. Without a ground the mast may become “electrically hot” exposing danger to persons and equipment. This condition can occur from faulty electrical equipment, bad wiring or a static charge build up. A “electrically hot” mast may result in electrical shock and electrolysis.
Some wind generators provide a separate ground lead that connects to the nacelle (wind generator body) via a slip ring and brush while others depend upon the mechanical connection to the mast itself and presumes the mast is connected to ships ground. Grounding issues become compromised when a nylon or rubber type isolator pad is placed between the mast and wind generator yaw clamp (used to isolate mechanical vibration) resulting in possible electrical isolation of the wind generator to the mast.
Additionally, the mast themselves may be mounted to the ships hull with isolation vibration absorbing rubber bushings use to help eliminate the mechanical vibration of the wind generator from making its way down to the hull of the boat.
In either case grounding of the mast and wind generator to the ships ground is imperative when mechanical isolated mounting techniques create the electrical isolation of the ships ground.
In the case where the yaw mounting clamp is isolated from the mast by a rubber or nylon pad, installing a small grounding jumper wire between the yaw clamp and the mast will provide the electrical grounding path between them.
The mast is easily grounded by running a wire from its metal shell down to the ships ground. Minimum wire size recommended would be a #10 AWG.
When install grounding wires on the metal structures and frames that support the wind generator only a single ground wire should be connected from the structure to the ships ground. (Multiple ground wires can result in current loops leading to possible dangerous voltages).