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Charge Controllers and Clippers => The "Classic" charge controller => Classic FAQs => Topic started by: bennyspoon on April 27, 2013, 01:31:12 AM

Title: diversion vs opportunity load question
Post by: bennyspoon on April 27, 2013, 01:31:12 AM
i have just ordered a classic 150 to include in my off grid system that i intend to connect to my solar array. i also have a hydro turbine that is currently regulated with a dc water heating element as a diversion load,connected directly to the battery bank. i would like to use the pwm facility of aux 2 to operate a relay for the diversion load. i am not interested in mppt for the hydro at this stage, i just want to heat water with the excess energy .my questions are,

1: does diversion load allow the usual charging timers for bulk, absorb etc to run or is it only opportunity load that does this?

2: if set to opportunity load, will this then allow me to utilize not only the excess from the hydro, but also from the solar, provided i have sufficient heating elements?

3: is there a better way of doing this by using both aux outputs?

thanks,
ben.
Title: Re: diversion vs opportunity load question
Post by: Halfcrazy on April 27, 2013, 05:57:47 AM
Ben
Diversion triggers at a fixed voltage so you loose 3 stage charging, but as you pointed out "Waste Not hi" (Called Opurtunity Hi in the manual) will trigger the relay and run the timers so you still get 3 stage charging and full diversion.

You are correct that provided the relay and resistors are sized correctly this can dump all the excess from solar and pv. I would use a solid state relay for this diversion and if it is true resistors I would use Aux2 PWM output. I would do a search for posts by ChrisOlson he has a library of Great info here on diversion with a Classic

Ryan
Title: Re: diversion vs opportunity load question
Post by: bennyspoon on April 27, 2013, 11:54:43 PM
thanks for that info ryan , i have had a look at those posts. i have a couple more questions.

if the resistors are undersized vs the panels, and opportunity hi is used, does the controller pwm the panels more or does this not work? as an example if i had 1 kw of panels and a resistor that was only rated to 10 amps@48 volts instead of 20-25 amps. does the cc pwm the panels more or does the load get maxed out and the excess then goes to the batteries?

also, is there any issue with running 2 or more solid state relays in parallel to
a] achieve the capacity for the load and
b] as a form of redundancy

is my thinking correct in this?

thanks again,
ben.