The Tank › how to get photovotaic-powered water heater pump to work?
- June 12, 2014 at 5:19 pm #20929
I have a solar water heater with a pump that has been powered by a photovoltaic panel. The pump has broken 3 times. The 1st two times, I had it replaced. I have the feeling that something fundamental is missing. I could use some help/advice.June 12, 2014 at 5:30 pm #20930energyexpertParticipant
Has it been the pump which has broken or the motor driving the pump which has quit? If the actual pump is the problem, what type of pump is it? Some types of pumps do not like dead headed conditions.
DavidJune 12, 2014 at 6:07 pm #20932
Hello: David is on track. 😎 Any information you can give about what pump it was and exactly how it failed would be useful. Photos help if you have them. Also a photo of the pump in place would help too.
Yours, LarryJune 13, 2014 at 7:14 pm #20941
The pump brand is March MFG. It’s model # 809-BR. I believe I am posting a photo of the pump’s name plate.
I haven’t tested the pump, but the original installer did and said it wasn’t working. I just checked the solar panel voltage — it’s 20 volts, which seems high to apply to a 12 volt motor.
As I tried to indicate, I know virtually nothing about electronics. I’d be completely happy to find someone who could fix the system. Barring that, I’d need some pretty detailed instructions to do it myself.June 13, 2014 at 7:34 pm #20942energyexpertParticipant
Your car’s “12 volt system” is actually a little higher with the alternator putting out maybe as high as 14 volts, but not 20. My guess is the pump/motor manufacturer would frown on the 20 volts. Practically 20 volts cannot be good on a 12 volt motor. 12 volts applied to the 6 volt starter on the old Ford 8N farm tractor really made the starter spin. We did not dare leave it on but for a few seconds. The solar panel guys should know where to get a regulator to reduce voltage down to the appropriate level.
DavidJune 14, 2014 at 3:12 am #20943
Hello: I’d make sure to check the solar voltage when it’s hooked up to a load (the pump). Collector voltage can run rather high when it’s not hooked up. I’d ask about the watt draw on the pump (12 volts times 1.5 amps is 18 watts) and what the watt output of the solar is. A big panel on a small pump will stress the pump. 😕
Yours, LarryJune 14, 2014 at 11:51 am #20944
The panel wasn’t hooked up to a load. The solar panel says:
Open Circuit Voltage 22
Peak Voltage 17
Watts: Solar panel says maximum wattage is 20 W.June 14, 2014 at 1:56 pm #20945
Hello: Here is a spec sheet on your pump. http://www.marchpump.com/809-br-brushtype/ . It says maximum voltage is 14, for the 12 volt pump. Perhaps the right next step is to call the manufacturer to see if they have any idea why their pumps are failing. The 20 watt solar panel does not seem oversized at all, but it’s voltage goes a bit to high.
Yours, LarryJune 14, 2014 at 3:59 pm #20946
Thanks. I’ll give it a shot.June 14, 2014 at 8:36 pm #20947
Hi: One more random thought would be to check the brushes in the motor to make sure they aren’t worn out.
- You must be logged in to reply to this topic.