GPS Wiring

[tom52]

Does anyone know if I can use ordinary 5amp wire for connecting the NMEA 'out' from my GPS to the NMEA 'ins' on my tiller pilot and cockpit GPS repeater ?

Or is there some special stuff required and is the length of the wiring run critical?

 

[brianrunyard]

The cable will be fine, within reason length is not a problem.

Brian
http://homepage.ntlworld.com/brunyard

 

[VMALLOWS]

It'll almost certainly work, but a bit over the top in terms of size. I'd say a bit of twisted-pair telephone cable would be easiest and cheapest. Just pick any pair out of the 2 or 4 or 6 pairs.

 

[Strathglass]

Just use a 5 amp domestic cable as used on a normal table lamp. It must however be multistrand and not single strand wire this will work initially but would hardly last a day in a marine enviorment. Do not be tempted to use less than 5 amp wire, as thin wire is very difficult to terminate adequately.

Iain

 

[tom52]

Re: GPS Wiring (thanks)

Thanks everyone.
I'll be threading the wire tomorrow !

 

[LadyInBed]

Re: Phone Wire

Yes, I used phone wire (about 7 mtrs) and it works fine. I did double up on the wires by twisting wires together to make just one pair, on the theory that unused wires could pick up stray signals and induce them into the wires used for the nmea.

 

[tome]

NMEA data can be run over long distances with tiny conductor sizes as there's no big current. Use the smallest wire size you have, but not smaller than 0.5 sq mm (22AWG) or you can't use crimp connectors. No problems with going to bigger sizes. As stated elsewhere avoid solid conductors as they fatigue and are unreliable.

If you really want reliability then form the conductors into twisted pairs. You can do this by cutting equal lengths and putting 1 end of each into a vice with the other ends in the chuck of a drill. Stand back from the vice with the drill until the wires go taut then start the drill. The wires will twist and you'll need to walk towards the vice keeping the wires taut. When you have about 5 twists to the inch (small wire size) you're done.

 

[yachtbits]

screens, cable routes and unwanted jibes!

telephone wire and mains flex!

I would be shot if i used that on a commercial vessel!

cable should be screened and the screen connected to 0v.

also, ensure that cable is not run along side any radar or vhf antenna cables. Also avoid any cables asociated with inverters.

doing it properly now, prevents anyone slating your work in a few years time when you change to another boat. Don't use telephone wire at all on boats!

we are currently doing a lot of work to a large bavaria that has had a load of equipment installed by a major marine electrical/elctronics company that considered it okay to mount an inverter directly below the Yeoman, and bundled the gps antenna in with some of the mains cables.

the resultant jibe that occurred the first time the inverter was switched on while in autopilot mode was apparently quite spectacular!

a little time and thought now may save greif and a wack on the head later!

kev

<A target="_blank" HREF=http://www.yachtbits.co.uk>http://www.yachtbits.co.uk</A>
sales@yachtbits.co.uk
marine electrics & electronics

 

[tome]

Re: screens, cable routes and unwanted jibes!

If using a screen connect it to ground at the NMEA talker end only

 

[gtmoore]

It's a shame that some of the manufacturers don't take note of this last point. The wiring to be found on my MLR fixed GPS is hairs breadth - I had to use 3amp lego block connectors but the wires are still far too thin.

While on this subject, I know there is an art to tidy wiring but why is it that when making these sorts of connections I always end up with something that looks like spaghetti? These NMEA connections are the worst with thick cables splitting into ultra thin ones that have to go to different places and need to be different lengths.

I need to rewire my boat soon cos all the new bits I buy just adds to the existing mess thats already there but I need to see some good installations to give me ideas as to how to make this sort of thing look neat.

Gavin