I need some assistance from the community. I can’t find a clear answer on the wiring of I/O ports to a 12v automotive relay.
To switch the relay on, set bank dip switch to off (0), then should the wiring be run:
Digital I/O Signal → Relay Pin 86 (Narva recomends pin 86 for switch +ve signal)
Digital I/O GND → Relay Pin 85 (Narva recomends pin 85 for ground)
This is my understanding, but this is the first time I have used a setup like this to operate relays.
Yes I know there are two relays on the IO Extender, but they are already allocated and I need 3 relays to open ball valves which are powered through the 12v relay.
Assume you are using the outputs of IO-Extender and assume you have a 12 Volt system (RCV?):
The transistor outputs of the IO Extender are switches to positive Ubat (see manual page 4). Therefore your suggestion for pin 85 and 86 are correct.
Nevertheless you need a freewheeling diode instead the build in resistor inside your Narva. This resistor increases the coil current to simulate older mechanical relais widely used by Trabant cars in East Germany. Connect anode to GND and cathode to output. If you have the Narva already, replace the resistor by 1N4007 diode . If not, buy one without resistor and with diode.
The Victron team might improve the documentation by:
use units for capacitive and inductive loads in German translation
