So I need to move my ESP based external fan control for cooling my MPPT to making use of the temperature sensor and relay on my Victron GX, it seems straight forward enough and have set it up but it’s just refusing to trigger the relay despite me moving through the temperatures I’ve set.
Based on my settings below it should come on at 35 degrees and switch off at 31 degrees but its not switching the relay at all, I’ve read a couple of posts online with guys doing the same thing and it looks like I’ve done it correctly, any idea’s?
Yes correct, originally I had 2 x AC fans with an ESP8266 and was using Home Assistant to switch the relay on when the temperature sensor on the ESP8266 went above a certain temp and off when it dropped below a certain temp.
I’ve sold my house and am taking my HA stuff with me hence the move to doing this with the GX and making use if its external temperature sensors and relays.
I have swapped the AC fans out for 12V fans purely so that it can all be powered via the GX (DC) as I don’t have an AC plug near the inverter anymore (was a compliance thing)
EDIT: The DC fans are smaller than I would have liked but I had them laying around and have been manually triggering them and they are making enough of a difference, I generate surplus power in summer anyway so they run for free.
If you have a 12v fan(s),and they already are 12v, and you have power. You can use the mppt relay to trigger the fans. The smart Mppt have a built-inrelay. You connect it bottom right.
You then use the relay controller of the mppt to activate and deactivate it.
Ive set mine on the voltage of the panels. So when the panels go over a certain voltage, it switch the fans on, af when it drops below a certain voltage, it switch off. I have 2 120mm pc fans. Mounted above the mppt.
In my experience that brings temperatures down by at least 20C - from peaks in the 80C range to peaks in the 60C range. I am confident that’s good enough.
This is exactly what I’ve done except I’m using the GX and not the MPPT and would prefer to keep it on the GX so that things can be configured via the web interface or Victron web portal, cant see why it would work on the MPPT and not GX anyway.
I didn’t realize at the time of install just how hot these got and when I did I also had the idea of mounting it on an aluminium plate but the way mine is installed this isn’t really a practical option so my only choice was the fans which I’ve had great success with and MPPT has never gone over 50 degrees, I’m in the Cape so we get some blinders in summer.
So I installed a plug timer, different times for Winter/Summer, to not only give some air movement around all noted above, but also for me, as I was sitting like 2m away from the system.
This fan, angled upwards, to blow up underneath the MPPT’s and inverter, drawing air from around the battery cabinet.
And because I’ve seen the temps inside the battery box, DIY one, during charging/discharging (hence the additional temps sensors over and above the BMS sensors), I have tested this fan on the top of the box last summer.
Think I’m going to make it a permanent feature, 220v onto the same timer plug as the fan.
Just need to decide do I want to install it at the bottom/top/side.
Titbit:
Keep in mind, the 220v power is free power.
