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aaa247 avatar image
aaa247 asked

100/20 solar connection problem

I have one 200w 24v panel reading 40v at the bare wire ends before connecting to the mppt. When I securely connect the wires to the mppt and check the voltage at the connection point, I get a reading of .7v does anyone know why this is happening?

MPPT Controllers
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Murray van Graan avatar image Murray van Graan commented ·

It might be that the MPPT is clamping down the input- do you have a battery connected? You can use VictronConnect to connect to the MPPT, that might also shed more light on why it does that

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aaa247 avatar image aaa247 Murray van Graan commented ·

I have VictronConnect and all readings for solar panel are 0.

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klim8skeptic avatar image klim8skeptic ♦ commented ·

Sounds like reverse polarity connection, check.

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2 Answers
Justin Cook avatar image
Justin Cook answered ·

@Aaa247, either your PV voltage is reversed or you have a bad MC4 connector. An improperly crimped/connected MC4 connector may show voltage but that will drop to 0v or thereabouts when a load is applied in an attempt to draw current through it.

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aaa247 avatar image aaa247 commented ·

Thanks Justin, I will check for reversed voltage but how do I check for a bad mc4 connecto?

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aaa247 avatar image
aaa247 answered ·

It was reversed. Thank you guys for all your help and recommendation!

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