Re: [Amel Yacht Owners] Re: Two questions
The drain and shield are connected together, and should be regarded as a single conductor. The drain wire is a lot easier to attach to than the shield.
Maretron has this to say:
The NMEA 2000® network should be grounded at ONE location. Grounding at more than one location may produce ground loops, which can cause problems with communications on the network. In addition to the ground wire, connect the drain or SHIELD wire at the supply ground location and NO other place.
I take this to mean both ground and drain should be connected to the output of the 12V converter that is powering the system, which is the way it is set up on my boat. This also matches general electrical engineering practice.
Part of the confusion I think is the use of the term "ground" for too many things. Every circuit has a chosen point that is the zero-volt reference, and this is called ground. The shield must be connected to the reference point of the power and signal wires to be effective. But on an Amel, we also have the 24VDC ground and the AC ground, which are all distinct. We even often call the DC ground by the slightly-inaccurate name "DC negative" to emphasize that it isn't connected to the AC ground.
Ryan and Kelly
SM 233 Iteration
Boston, MA, USA
On Fri, Jun 1, 2018 at 4:11 AM, divanz620@... [amelyachtowners] <amelyachtowners@...> wrote: