Thank you for the feedback, once again!
The alternators will not
be disconnected from the 24V house battery
So it seems I am good with my setup. I am almost done, just need a few more connections and then the replacement MC-624.
I got two three-position switched (1 - OFF - 2 rotary type), and two red light/beepers. I tested starboard side static (without running the engine), and it works fine. All cables
measured for connection and against shorts, all checks.
little "mistake": I placed the MC-624s so that it made most sense for me with the cables
. Only when I fired starboard up (ignition only, no running), it dawned on me that the display was upside-down! Doesn't really mean anything for how the system works, but I re-fitted it again (which meant some cables were too short).
After it's all done, I'll make a video (time permitting) of how the system works in my setup. I am very satisfied of the outcome so far.
About the temperature sensors: I thought they were PT1000/KTY style resistive sensors. It seems, however, that they are simply making contact (short) at a certain temperature, set in the probe itself. Hence (as the manual says), shorting any of Alternator
, Bat 1 or Bat 2 pins on the MC-624 will trigger a warning AND set the load down to 50%. But also too high or too low voltage will trigger the warning.
To cancel an alarm
I will need to pull a cable off. This could be the case if the alternator
is above the normal temperature, but for some reason I want it to keep going at 50% load (but don't want the continous warning). I do have fans and ducting installed next to the alternators, to draw away excess heat. I might even consider to couple the overtemp warning to the fans, for automatic fan operation. Or even add on one of these to each alternator fan:
This is a very simple relay thermostat which I could set at - say - 100F - so the fans will not run until required, but before the overtemp comes on.
By ignition on, and alternator on, the warning IS on before starting the engines (together with the pre-engine start beeper).