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netdesert avatar image
netdesert asked

I too would like an alarm when PV input goes off.

Built a small UPS using SS MPPT 75/10 and CERBO S GX. PV input to the 75/10 is from a mains powered 24vdc p.s. rather than solar panels. I would like to produce an alarm condition when the mains to the 24vdc p.s. fail. Can’t figure out how to do it. Any ideas? TNX

vrm alarm
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kevgermany avatar image kevgermany ♦♦ commented ·
Not likely to be easy. If it was the case, everyone using it for real PV would have an alarm every time the sun went down and also with heavy clouds.
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Alex Pescaru avatar image Alex Pescaru kevgermany ♦♦ commented ·

The PV voltage, even with heavy clouds, will always be above "night" voltage, above tracker's start voltage.

Starting from this assumption, there is a register, VE_REG_LINK_RTC_SOLAR, which is 1 during day and 0 during night.

Not to mention the VE_REG_DC_INPUT_MPP_MODE, which reflects almost the same thing.

But the OP need to be able to get these info, from Modbus, dbus or directly from the CANBus.

Or maybe a NodeRed implementation with the above.

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Al avatar image
Al answered ·

I did this on a community water pump system that's in an area liable to theft, the solar panels always produce a few volts even at night, so in case the panels cables are cut or stolen the voltage will go to 0 and alarm, you can modify the alarm rule in VRM for your power supply voltage disappearing.


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