VCM100 grounding requirements
The Magnum is not grounded directly, but is connected to ground via the VCM100. The following grounding requirements apply to the VCM100:
The VCM100 power cable screen must be connected to the vessel’s common ground point.
It is recommended that the common ground point is a bonded ground, i.e. with the ground point connected to battery negative, and situated as close as possible to the battery negative terminal. If a bonded ground system is not possible, a non-bonded RF ground may be used.
VCM100groundingGroundingVCM100

A — Bonded ground system (preferred)
B — RF ground system (alternative)
Power cable to VCM100.
VCM100 drain (screen).
Bonded (preferred) or non-bonded RF ground.
Power supply.
Implementation
If several items require grounding, they may first be connected to a single local point (e.g. within a switch panel), with this point connected via a single, appropriately-rated conductor, to the boat’s common ground. The preferred minimum requirement for the path to ground (bonded or non-bonded) is via a flat tinned copper braid, with a 30 A rating (1/4 inch) or greater. If this is not possible, an equivalent stranded wire conductor maybe used, rated as follows:
for runs of <1 m (3 ft), use 6 mm2 (#10 AWG) or greater.
for runs of >1 m (3 ft), use 8 mm2 (#8 AWG) or greater.
In any grounding system, always keep the length of connecting braid or wires as short as possible.
Do NOT connect this product to a positively-grounded power system.
References and best practice
InstallationBest practiceIt is recommended that best practice is observed in all vessel electrical installations, as detailed in the following standards:
BMEA Code of Practice for Electrical and Electronic Installations in Boats
NMEA 0400 Installation Standard
ISO 13297: Small craft — Electrical systems — Alternating and direct current installations
ISO 10133: Small craft — Electrical systems — Extra-low-voltage d.c. installations
ABYC E-11 AC & DC Electrical Systems on Boats
ABYC A-31 Battery chargers and Inverters
ABYC TE-4 Lightning Protection