issue w/Victron Energy SmartSolar MPPT 75V 15 amp

Bob B

Photon Sorcerer
Joined
Sep 21, 2019
Messages
4,349
There is an internal fuse that could affect current readings .... if possible test the current flow in in a different circuit to make sure you are getting good readings from the meter.

You can test the internal fuse .... see the diagram below.
1629592441454.png
 

photo2000a

New Member
Joined
Aug 19, 2021
Messages
15
hi. i got a 12v 7w light bulb incandescent measured the solar cells again got exact same reading when trying to read the amps in series w/it. I also tried reading across. a used aa battery and got 6.6. so seems the meter is working. i have another simular meter. got same readings. could it be. i got 2 bad panels?
 

chrisski

Solar Boondocker
Joined
Aug 14, 2020
Messages
3,257
hi. i got a 12v 7w light bulb incandescent measured the solar cells again got exact same reading when trying to read the amps in series w/it. I also tried reading across. a used aa battery and got 6.6. so seems the meter is working. i have another simular meter. got same readings. could it be. i got 2 bad panels?
So you proved something is not right between both leads. If both panels are hooked in series on the roof with wire going down, any connection and wire could be bad.

If its just the panels at the MC4 leads, the only thing that could be wrong is the bypass diode could be busted. Ohm across the diode and should be very low amps one way and when you switch the leads, on open circuit.

If the wiring tested good, and the diodes tested good, the panel would be bad. If the panel is bad, I’d appreciate a description if anything was visually wrong or not. I watched a pretty long video testing a panel that went bad, and at the end he said he did not know why it was bad.

Here’s the inconclusive video but pretty good at the procedures:

 

photo2000a

New Member
Joined
Aug 19, 2021
Messages
15
hi. i am just testing the panels individually at there pig tails , i did the ohm test. was zero one way. and 5 reversed. on both. can someone confirm if it seems like both panels are bad based on the results. of the suggested tests. do we have enough tests. to point me?
 

chrisski

Solar Boondocker
Joined
Aug 14, 2020
Messages
3,257
hi. i am just testing the panels individually at there pig tails , i did the ohm test. was zero one way. and 5 reversed. on both. can someone confirm if it seems like both panels are bad based on the results. of the suggested tests. do we have enough tests. to point me?
To test the diodes, need to pop the plastic cover and touch the leads of the diodes. If there’s no diodes, they will be built in the panel and not accessible.
 

photo2000a

New Member
Joined
Aug 19, 2021
Messages
15
hi. there is no way for me to get direct access. to the diodes, i just need to do a test. to see if the panel is good or bad, not looking to see what in the panel maybe bad. if its fair based on the test results i posted to say it is in fact defective best for me to try and return it. and pick another brand. and hope i can get a good one. someone here posted many of these. seem problematic so. kinda. scary but. appreciate. the help very much.
 

chrisski

Solar Boondocker
Joined
Aug 14, 2020
Messages
3,257
If you have tested the ampmeter on something to prove amps can be read with the meter, then there you have done all you can to test this panel.

Some newer panels are supposed to have these diodes built in. If that's the case, there's nothing you can do to fix them. They put the diodes internal because these diodes fail so rarely.
 

photo2000a

New Member
Joined
Aug 19, 2021
Messages
15
ok thanks Chrisski, yes i did the tests. people here suggested for the amps which seemed to be simular to the amps reading of my controller when i hooked that up it shows zero amps always ok so. guess bad luck i got 2. defective panels from 2 different suppliers. not sure if i should try another sunpower. or try a renology. just need a small 50w flexible panel does anyone have thoughts on that brand wise??
 
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