Dump load questions

[cornwallav8r]

What I have done for dump loading

I know this is an old thread but...
For my RV, I installed a 220 watt solar panel on the roof. Designed a 2-stage microcontroller dump controller, which allows a preset user changeable window of operation.
I set it for 12.9v and 13.4v window....it boots up on solar panel voltage, shuts off after sunset. The panel is default in parallel (NC contacts of a controlled relay) with the battery, charging. When the upper window limit is reached (13.4v) a first stage dump relay is thrown (a 12v diesel glow plug in the 6 gallon water heater drain plug thread). It dumps till the lower voltage is reached-i.e battery still full voltage) The dump heater is limit controlled by a surplus water heater thermostat tank mounted switch-no boiling over. There is a 2nd stage relay which is thrown if a 10 second timeout trips due to charging voltage still exceeding the upper 13.4v window voltage. This is wired across the existing 12v heater in the 3-way fridge. Gives priority to dumping. During the day, with just the fantastic overhead fan on low speed as a load, the dump is operating almost 60% of the time to the water heater. On a really sunny day the fridge gets power too.

This week I will revise the system....parallelling a solar panel with a 33v open circuit voltage, to a 12v battery bank loses lots of available power. Will insert a DC-DC converter in series to swap current for voltage, roughly doubling the output current.

[Freezer66]

My Newbie 2 cents.

On some solar controllers there is an indicator light (full, charged, etc.) which you could tap into to activate a relay which would then transfer that "dump load" to a box fan heater with a thermostat or a separate water heater with a thermostat.

If you don't have that indicator light as previously mentioned, why couldn't you have a 2 or 3 pole relay and think of it like a IF/THEN statement. If my battery bank reaches X volts then "toggle" and send "dump load" to secondary device.

Heck you could even have it charge up your vacuum cleaning robot and come home to a clean house! Obviously, there are many other uses and I’m not getting into the details since there are SO MANY variables out there. Ultilizing a voltage sensor module from Arduino or a Raspberry Pi are super easy and in expensive. EXAMPLE: http://www.emartee.com/product/42082...o%20Compatible

My moto “KISS”.

[asdex]

Dump load connection and water heating

Hi, I have been designing my system and have fitted in a dump load for the wind generator. I just read there is an advantage of keeping the wind generator always connected to the battery bank and switching the dump load in and out in parallel. Not sure if that's a good idea and was wondering if someone would know the pros and cons?
I have attached my design so far in case anyone finds it useful.

Version 5 drawing.jpg

[asdex]

Latest version:Power system Ver 14.pdf
Starting install this week.

[inetdog]

Hi, I have been designing my system and have fitted in a dump load for the wind generator. I just read there is an advantage of keeping the wind generator always connected to the battery bank and switching the dump load in and out in parallel. Not sure if that's a good idea and was wondering if someone would know the pros and cons?
I have attached my design so far in case anyone finds it useful.

[ATTACH]7305[/ATTACH]

One problem with having the dump load switched in and out in parallel with the batteries is that it will cause fluctuations in the battery voltage that may interfere with the stage progression in any other connected charger.
If wind is the only charging source it might be OK or even preferable.