Installing Raymarine chartplotter

[andrewd01]

I have a question about the electrical connections when installing a Raymarine plotter. The connections for the red and black wires are obvious, but what do I connect the RF shield to? A sales assistant in the shop I bought the plotter from suggested that the RF shield can be connected together with the black cable. Does this sound correct?

Any practical advice from people who have installed these plotters would be helpful (It's an A60). There's a great article in Yacting Monthly about installing these plotters but it doesn't mention the RF shield.

cheers

 

[RestlessL]

As a general principle the shield should be connected to ground (i.e. to the black wire) at one end only. If there is a choice this should be the end which sends data down the wire (the NMEA "Talker")

Be warned, however, that in some equipment the shield is used as the earth wire, and so the shield needs to be connected at both ends (the NASA wind sensor and GPS repeaters are examples)

John

 

[alan]

Yes it can be connected to the black. The reason for having separate wires is that in "professional" installations (not necessarily boats) it is normal to have a power ground and a signal ground network. Thus any noise on the power ground will not be tranferred to the signal ground; it is also normal to separate out these grounds into separate cable ducts, so they are not close to one another. However, on small installations (e.g. boats) it is too complicated and expensive to do this, so there is only one ground ............... so you can connect the shield to the black wire; actually on my C70 I just cut it back and didn't use it.

Alan.

 

[PCUK]

On my steel boat it went to ground on the hull. Connecting to the black is more common and works fine although the ideal on a GRP boat is to have it grounded to an earth plate on the hull. As already said not really worth the additional effort.

 

[andrewd01]

thanks for your help

cheers