ChronicHydronic
New Member
- 2-300watt panels that will be roof mounted
- 48vdc 1000watt water heating element, but my reading suggests a higher resistence AC element may work better as Panels are rarely working at peak.
- The infloor system has it's own grid tied electric boiler so I am just trying to preheat the water to save on electric bills....not run the whole system. (It's just really an experiment to learn about solar)
It appears an MPT controller type system is required to get the most out of my panels located in NS Canada. There is a new (improved?) controller version of the AC7391 that I looked at previously.
The Actii AC7392 shown below looks interesting but in reading the manual I have some safety concerns. See the 2 comments from the manual
COMMENT 1
"- The regulator must be absolutely disconnected from the panels when we leave the apartment for more than a day!!!"
COMMENT 2
"ER.1 Means damage to the control transistor, immediately disconnect the regulator and send it back to the service. At the time of displaying this error, the heater is constantly powered from the panels and the regulator is not able to turn it off! Leaving the regulator with this error can lead to its melting and even fire."
PWM controller MPPT heating water heating rod photovoltaic solar modules solar PV 3KW 6931240073926 | eBay
So my newbie question. Does it make any sense to use a Victron mppt controller to charge 2 batteries and hook a DC heating element directly to the batteries? or go back to AC through an inverter? That way in the summer I can also use the controller/battery/inverter to run some appliances and I don't need to buy an ACTII unit that might burn the house down.
FOLLOW ON QUESTION
I have read "efficientPV"'s comments with great interest and his answer to another post (below) and the concept that other's xcel formulas may not be ideal:
"""That peak ideal resistance is good for less than 2 hours each day. It is better to design for a much lower current. If you often get haze or clouds, a 5500W 240V element would be 10.5 ohms and give better daily performance with two panels in series. Even the 2000W 120V element would work well with one panel. Save that extra money for another panel later.""""
I purchased a 48vdc 1000watt heater. I am happy enough to buy another AC heater if a higher resistence makes more sense. Just wonder what my best configuration of panels and heating element would be from your experience?
If anyone has any usage comments on the Actii controllers, I think many of us would be happy to hear them.
Thanks In advance Glen
