Actisense & Furuno N2K junction boxes, impressions
I used Actisense’s QNB-1 Quick Network Block, above and bigger here, to create Gizmo’s little NMEA 2000 network, and it pretty much lived up to expectations. While using regular tees and fixed cable lengths would have been messy in the small confines of my console, this junction box let me cut cables to length and still end up with a fairly waterproof system. The built-in fuses and LED status lights made the install easier, and those cable glands provide good strain relief on a variety of cable sizes (add Tommy Tape when they don’t). But I must say that fixing wires to the terminal strips can be tedious, and downright hard in tight quarters (I did most of the wiring on a bench).
But maybe the hard-to-wire complaint is just due to my experience with how easy it is to wire Furuno’s similar FI5002 junction box. As you can see in the photo below, and bigger here, Furuno used Wago terminal blocks which can be unplugged for easy wiring. Note, though, that the FI5002 is a lot less weather proof than the QNB-1, and lacks built in fuses and status LEDs. But it does have little jumpers (not visible in the picture) that can be set to terminate either or both ends of the backbone. If you want to use the QNB-1 as a complete backbone you have to wire in two short cables with terminators attached.
Interestingly, the QNB-1 doesn’t delineate which two of the eight cable connections are for the backbone, and I don’t think it really matters on the FI5002 either, except that it has two extra-large terminal blocks in case you backbone with Mini-size cable instead of Micro. In other words, the architecture of these junction boxes seems more like a star than the linear backbone/tee/drop we’re used to.
Finally, Actisense announced a reconfigured NDC-4 NMEA 0183 multiplexer today. It sounds good, but the press release description also suggests some of the 0183 issues you won’t run into using N2K.