Your nmea2000 network might be in danger

[Fuss]

I damaged all my 12v instruments because the 24 12v converter after 8 years decided to output 31v.
I then swapped to nmea2000 and new instruments.

All instruments regardless of voltage should run through a converter to reduce the chances of spike voltage damage.

My new setup, in the hope to not have to learn lessons twice is to use a Victron isolated 24 12 smart converter set to output 13v. Then after this a voltage relay says…if voltage gt 14, then disconnect.

[Avionics_Joe]

I don't think a relay will be fast enough. I would put a large 14-volt Zener diode and a fuse on the output.

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[HankOnthewater]

Such 14 Volt zener diode would protect the circuit from the 24 volt system, but...... it is too low for a 12 volt system, where alternators generally provide more, and, when equalizing batteries, voltage can be as high as 15-16 Volt.

And yes, a faulty solar controller or windgen controller will output a lot more than 16 Volt.

[Avionics_Joe]

I did not mean for it to replace the Victron isolated 24 12 smart converter set to output at 13v but just to quickly blow an appropriately sized fuse on the output in the unlikely event of the Victron failing.

[Hartleyg]

Just a note - a zener will absorb & dissipate a fast-moving voltage spike, but are not good at shunting a longer-term overload, such as a malfunctioning alternator or power supply. A Transient Voltage Suppression (TVS) diode - also known as "TransZorbs" will conduct enough current to blow a reasonably-sized fuse without destruction.



Hartley
S/V Atsa