TL;DR: the switches that set the in/out direction of the I/Os on the Extender 150 may change positions due to vibration.
Full story:
I may have hit a possible mechanical problem with the switches that set I/O direction on the Extender 150.
I have a relatively complex van set-up that has more relays that can be controlled by the built-in relays in the Cerbo GX and Extender 150. I set one bank of the I/Os on the 150 to be outputs, and drive a couple of MOSFET-based drivers to control the coils on external relays. Worked great for a while, until it didn’t (several months, many thousands of miles).
Normally I can hear the click of the relays turning on and off, but these weren’t clicking when being controlled by the Cerbo. They clicked and worked fine when the override switches were activated (all the relays have an accessible SP3T switch with 3 positions: controlled by Cerbo, relay in NC position, relay in NO position). Only the two relays controlled by the I/Os on the extender were affected; the other relays controlled by the internal relays on the Cerbo and extender worked fine.
The Cerbo and extender are in a separate electronics box that’s installed in such a way that the switches can’t be touched with installed, which makes debugging a little challenging but also makes accidental changes by me essentially impossible. The Cerbo and Extender are mounted horizontally, not vertically.
I removed the box with the Cerbo and extender from the vehicle and examined the connections and switches. The connections looked fine, I didn’t touch them. The switch for the bank of I/O used as outputs looked out of position, like it was close to the “input” position, not the “output” position.
I pushed both switches solidly to the down/“input” position, then to the up/“output” position, and then the switch for the bank used as inputs to the down/“input” position.
Now the switches looked very clearly apart from each other; one was clearly up, and the other down. Before, the “up” switch looked a lot closer to the down position. There was a distinct snap when moving the switches from down to up and up to down that was not present when moving the misplaced switch initial to the down position.
I have a suspicion that the switches are vulnerable to mechanical vibration and are being bumped out of position by mechanical shocks normal to on-road and off-road driving.. Ugh, nasty problem if that’s the case. They are the first switch of that type (small simple slider) I’ve seen on a Victron product (but very limited exposure). It may be that a toggle of some sort is needed in place of that. It makes me wonder if that was tested in shock and vibration testing.
Just a heads-up to other users, and a reply from Victron would be nice.