There are a number of people who are using, or planning to use, a Crydom 0-10v proportional controller to divert surplus energy to their immersion, and I thought it would be a good idea to continue those discussions in a single location, rather than scattered through the rather long solar energy management thread.
A question for those who have already done this is what update rate are you using? I think Dennis said he was doing this at around 100 per minute. Does the emonglcd get updated at this rate as well?
And a second question. Are you worried about the state of the immersion thermostat? ie what happens when the tank of water is up to temperature.
Lloyd
Re: Designs Using Crydom
Yes the emonGLCD get's updated at this rate, as does the emonbase.
I have had to insert a delay into the emonbase to prevent continuous network updating but this has caused occasional errors. I have now adjusted the code to something I hope works better using millis(), but I will only be home in 8 days time to test it.
I did do some changes in the emonGLCD but I will need to look at the code to remember what, but I quite like the faster screen updates - the delay already in the programming prevents illegible updates, probably to about 1 change per second. As I added a third CT to measure diverted power I added some lines in the program so that instead of displaying exported power, it now displays the power going to the heater aswell as turning the LED's orange. Kind of like if power3 > 15 then display the power3, else display the imported/exported power as standard. It's quite nice seeing at a distance the LED's glowing orange. I've a few more idea's on this but I'm working on another energy saving idea's just now - I had never heard of Openernergymonitor and arduino before March but it's nearly all I'm thinking about these days, much to my wife's annoyance (she'll get over it!).
For the immersion thermostat, this at the moment is in operation and doesn't appear to be causing any issues but I have re-wrote the programming so that it will cut out via a software limit (also having to wait for testing). I also measure the hot tank temperature at immersion level, tank center and outlet for this purpose.
Dennis
Re: Designs Using Crydom
I have an emonTX (no 1) adjacent to my consumer unit, reading generated (solar) power, and consumed power. I intend to place a second emonTX (no 2!) in the airing cupboard, and use that to control the crydom. I want to measure the power being used by the immersion for feedback, but I have a dilemma on its best location. I don't really want to put the sensor in the consumer unit (but will if I have to), and my other option is to measure on the second emonTX. This would mean transmitting from no1 to no2 the power generated and being consumed, and using that to control the output. I would then want to transmit from both tx to the emonglcd and emonbase.
Does this sound feasible?
Lloyd