This video should wrap up the upgrade of the AC diversion load system to 1800W total capacity. We'll take a look at the code changes that got this working and fixed a number of minor issues that popped up as a result of those changes.

I've now modified the code to allow for parallel operation of the 2 diversion loads. Initially, I would block changes to one diversion load if the other diversion load was active, as it was likely assisting the first diversion load. I did this to make sure the assisting load was shut down first before reducing the other load. This assist mode happened quite frequently with just one 600W load on each line.

Initially, I was trying to stick to the device parameters as much as possible and total dimmer setting was the only parameter I had access to. After making the change from specific device properties over to a conditional expressions, that opened up the possibility of using only the assist mode portion of the dimmer setting. With the added capacity of the Line 2 load, assist mode operation should be very limited, so most of the time, both dimmers can shut down at the same time.

Doing this one simple code change gave the system a "look ahead" feature. Before, I had to wait one 15 sec. time interval to see if the dimmer on the other line had changed. Now, I can see if it will be changing in the current time interval. The dimmers on Line 2 physically update a few seconds before the dimmer on Line 1. This also shows the benefit of having many, simple conditional expressions instead of a few massive "all in one" expressions. It makes it possible to pick out one small bit of a calculation and use that in multiple expressions.

This all comes into play during cloud edge effects. With a shot of clear winter sun on the panels, there can be 100s of watts of excess power into the system for a short time. That causes one or both diversion loads to ramp up high. Then, a cloud might blow over and shade the panels. Now, there's lots of excess load in the system and the diversion loads should ramp down, as fast as possible. During this ramp down time, the diversion loads are pulling power from the grid, so it's desirable to minimize that excess power draw integrated over time (i.e. less KWH from the grid).

Finally, I improved the damping code to use a programmable damping factor. This will help to both speed up the dimmer shut down time as well as give a tuning parameter in case an instability is encountered. I chose the Euler constant, "e", as a good place to start. This approximates what an ResistorCapacitor circuit would discharge in with a 15 second time constant.

Making use of Notepad++ (https://notepadplusplus.org/) to keep track of code changes and comments is very helpful. I was able to go back to my original comments on the Share/Assist mode interactions to see what my initial intention was with that code. Once I understood that, it was easy to make a one line change to improve operation a great deal.

Also, these YouTube videos help to document the operation of the code. Talking through how something operates and then viewing that a year or two later is much better than a few lines of comments.

Simple plan is to add a radiant oil heater, as a 600W resistive load, to a ZWave controlled light dimmer and use that as an additional diversion load for the solar power system. This will increase the capacity of the load on Line 2 to 1200W with the original 600W load on Line 1. Note: Line 1 and 2 are the two 120V split phases/legs of the 240V house power circuit.

As far as installation, I have outlets in the family room that are on the Line 2 side of the breaker panel. Both the original DIversionLoad2 and the new DiversionLoad3 are plugged into one of those 20 amp outlets. Likewise, my original DiversionLoad1 is plugged into an outlet in the living room that's on the Line 1 side of the breaker panel. That way, each of the diversion loads, only uses up excess power on the side of the breaker panel they're plugged into.

Parts used:
600 watt ZWave light dimmer:
https://amzn.to/4aeyOF5
Used the UtraPro model: https://amzn.to/3ViUmMS
Picked up a dual gang electrical box, cable clamp and cover plate at a hardware store. I had an old PC power cable for the cord and an old receptacle left over from swapping in a GFCI outlet.

Radiant oil heaters, you want a simple heater, no digital display or push buttons:
https://amzn.to/3Vdnbdz
Used the Kismile unit: https://amzn.to/43lr81F

In the next video, we'll look at some code additional updates...
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Intro/Outro:
Louisiana Fairytale by Austin Rogers
https://web.archive.org/web/201704022...