Grounding-Dedicated drain wire for ACU-100

[Chuck - Raymarine - Moderator]

marchem,

The drain (“screen” or “RF ground”) wire provides a ground return for noise and transient disturbances on the power supply that could interfere with the ACU-100 - the larger the drain wire, the lower the impedance and the more effective the connection will be.

The installation guide gives a preferred minimum drain wire size, for all ACU types, of 8awg for runs of >1m. This is based on the ACU-200/300/400 which have a crimp terminal connection for the drain wire that can handle this wire size. Unlike the ACU200/300/400 the ACU-100 uses a sealed connector (for above-decks use) that accepts 12awg (2.5mm2) max - this is the preferred drain wire size for the ACU-100.