New Member with NMEA 2000 question

Hello all, I have read this site for a while and am finally becoming a member.
I have a Garmin 200 and a 740S chartplotter. I bought a NMEA 2000 starter kit from Garmin and would like to hook these together.
The kit comes with a power supply for the 'backbone' which is fused at 3 amps.
This would be ok for the chartplotter but the radio seems to require 7 amps. This means that the fused supply should be 10 amps?
Can I get a larger supply cable? Can I hook another power source directly to the radio and still have the NMEA 2000 hooked up without damaging either?
Thanks in advance for any advice offered.

Greetings,
Welcome aboard.

In a very small setup it is somtimes possible to power everything off the backbone with a special cable, but normally the backbone power is only for the support devices that attach to the backbone like GPS antennas, compasses etc. and not for large items like Plotters or radar which are powered separately. Your radio definitely needs its own dedicated power feed and I strongly suggest the plotter have its own also.

Ken

The radio isn't powered by the network. It draws a very small current for data transmission.

Ted

Thanks very much
I was concerned that powering the radio and plotter maight somehow 'backfeed' into the power supply for the backbone. But what you say makes perfect sense so I will have dedicated power supplies for both radio and plotter. It will still be ok to have the 3 amp supply as well correct?

3 amps is plenty for the NMEA2000 network backbone for what you're setting up. Anything that needs more power (RADAR domes, plotters, entertainment systems, etc.) will be wired for their own power supply. I upgraded my power cat to NMEA2000 last year. All electronics as well as my Honda outboards are tied into the network. The only two items that pull power from the backbone are the transducer and the SiriusXM antenna. Everything else has its own power supply/source.

O C Diver said:

The radio isn't powered by the network. It draws a very small current for data transmission.

Ted

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Garmin is notorious for this type of thing. The original GMI-10 displays required external power even though the manual said it could be powered by NMEA2K. I can't tell you how much time I wasted troubleshooting that NMEA2K power issue before I got a second level Garmin tech who knew that.

N2K is really just CANbus, it's everywhere. Just watch the lengths and termination resistors and it works great.

I'm really going to miss all the NMEA2000 engine information when I switch from my cat to my trawler. But then again the old Perkins diesels on the trawler are EMP proof

mixman said:

I'm really going to miss all the NMEA2000 engine information when I switch from my cat to my trawler. But then again the old Perkins diesels on the trawler are EMP proof

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Just install a Noland RS11 or similar on your trawler and get the engine info you need.

Thanks guys for all your help
The power supply deal had me confused
I knew if I asked on here someone could educate me a bit.

Has anyone had good luck converting their engine gauges over to nmea 2000 and was it a lot of problem solving.