Sorry jviss, that is still on my to-do list. Right now I am trying to track down a very small refrigerant leak (stops cooling after a couple of days. After that I plan to install the ISEC. From everything I can find you just need to remove the AB control module and connect the ISEC to the DF module.
No worries, I have a list of projects to-do decades long.
You are correct, the AB module goes. In fact, it doesn't add much value, in fact, even the diagnostic blink codes come out of the Danfoss controller that it front-ends. I haven't found a schematic or examined one, but I infer it just adds the LED (that could also be plugged into the Danfoss box,) a three fuses and a connector for the thermostat with wires for digital thermostat power. It is also a failure point, as folks have experienced burnt PCB traces from power supply current, and other things.
Likewise, I haven't found a schematic for, or examined an ISEC, and I confess that the documentation is odd; it has the ring, at times, of cultish or occult writings! But what I infer that it does is two things:
- provide for a different set point for the thermostat for when a charging source is detected;
- control compressor speed based on cooling load (maybe).
The Danfoss DB35F and DB50F compressors are variable speed compressors. Danfoss makes a controller, the AEO (Adaptive Energy Optimization controller), 101N0300, that controls the compressor speed and adapts to compressor run times to optimize run times; in short, it adjusts speed for a 30 minute "on" time. They are very clear about how they do this.
ISEC, on the other hand, does not disclose any algorithm.
The Danfoss AEO replaces the stock controller. That's all you need if you want. Or, you can plug the AB diag box back into it. It's more money than the ISEC, about double, and you don't get the nice second set point and charging source detection (which I had thought of before I even heard of these, and had crudely implemented by just using a charge combiner to short my thermostat wires).
I just learned about the variable speed compressor and the AEO today. Up until now I had a circuit worked out to use two Inkbird ST-1000 temperature controllers, one for battery operation, and the second for charging source operation. My charging combiner circuit would combine the controllers' "cooling" relay outputs (you can "wire-OR" multiple thermostats). The first set for 40º F, the second for 32º F (to prevent freezing food). Now, considering compressor speed, I'm back to the drawing board. Might have to go with a microcontroller. That would tempt me to add detection of the door switches on the ice box (Yes! Tartan put switches on the doors!) and maybe some more temperature sensors, fan controllers, and so on, to the point that I never implement it.
Or, I could stay with my dual-Inkbird design and just buy the AEO controller. By the way, my existing controller, 101N0212, circa 2016, includes a 1-Wire communications channel. Using this you can read out info, and also, use a negative temperature coefficient resistor temp sensor and set temperature set point and compressor speed via your PC (so, the controller has a built-in thermostat). You will need a 1-Wire to USB gateway, though.
The AOE is around $250. The Inkbirds can be had for $15 or less on eBay or Amazon.
Looking forward to how yours works out, Hayden! I'll let you know what I decide and if I make any progress on mine .
Cheers,
jv
