Remote switch for inverter: next level

[s/v Jedi]

This is for a 24V Victron Phoenix inverter. You can use the diagram for a 12V or a 48V model as well, but you need to calculate the resistor values for those voltages. Link to spec sheet: https://www.victronenergy.com/upload...-1200VA-EN.pdf

We use these small inverters (250VA - 1200VA) for use in a cabin, so that the big inverters can be switched off. The small inverters are used for a fan, entertainment system, charge a phone etc. They are often used all night.

The switch used is from APIELE: pretty, waterproof, 3/4" / 19mm diameter with a built in LED ring. There is a resistor inside the switch to connect the LED straight to 12V for automotive applications. This means we need to do something for different voltages anyway, but it is much too bright at 12V so it requires modification no matter what.
The yellow wire from the switch is the Normally Closed contact, which isn't used.

This diagram results in a dim LED ring whenever the fuse box has power (for us, this means when the cabin breaker is switched ON). When you press the switch, the LED ring becomes brighter and the inverter comes on.

The remote connector of the inverter has two pins. Remove the wire bridge from the connector (you can pull the connector off the inverter) and connect the circuit from the switch to the left hand contact of the connector. Leave the right hand contact disconnected.

I have tested this with the green LED version of this switch. At 12V the LED current is 7mA. The resistor values in the diagram set the current to only 2mA when the inverter is on and a minute 0.1mA when the inverter is off. This is for a 24V feed.

The diode is to isolate the inverter remote input from the LED. You can solder and hide these components inside heat shrink, straight on the wiring.

The overall dimmed function takes away the annoying bright LED at night. It also shows that the inverter has power even when switched off. We use the same kind of switches for lights where we use a blue LED ring; by lighting the rings even when off, you can identify what it is for by the color and by changing intensity you also get feedback if the circuit is off or on.

[s/v Jedi]

I’ve looked at the diode when using a 48V system. I can think of a scenario where it’s better to have a diode with a higher voltage rating, so for 48V I recommend to change the diode to a 1N4002 which can block up to 100V.

If you need to buy components then this diode also works for 12V and 24V. During normal operation it only needs to block a couple of volts (think less than 3V) but when the 220k resistor would short (which they never do) or when the green and red wires short out (this will blow a 1N4001 diode with a 48V house voltage but it also probably blows the LED inside the switch… don’t short the wires )

[PaulCrawhorn]

Thanks, nice contribution!