Down conductor connection system, wind turbine lightning protection system, and method for arranging a down conductor connection system

A down conductor connection system for a lightning protection system adapted to protect a wind turbine blade from lightning strikes, said lightning protection system having a down conductor cable adapted to extend in a longitudinal direction of said wind turbine blade and being connected to a root end of said wind turbine blade, and a number of lightning receptors electrically connected to and distributed along the length of said down conductor cable,

• wherein the down conductor cable is modular and having a first and second down conductor cable part, and at least one down conductor connector arranged between and connected to ends of said first and second down conductor cable parts,
• said at least one down conductor connector having a first terminal connected to an end of the first down connector cable part, and a second terminal connected to an end of the second down conductor cable part,
• said first and second terminals being adapted for mutual connection, such that when being connected, said first and second down conductor cable parts at least partly define said modular down conductor cable, and
• wherein said at least one down conductor connector comprises semi-conductive layers, each being arranged around a respective first end of said first and second terminals and said ends of said first and second down conductor cable parts, respectively, thereby partly enclosing said first and second terminals and any uninsulated end part of said first and second down conductor cable parts.