MC4 questions (still confusing to me)

[JWWRadio]

So what's up with MC4 connectors? I read somewhere that the little red o-ring had some significance (polarity). I bought some "Y" splitters and I am trying to figure out how to properly wire two panels, together.

If you look at this diagram from a product on Amazon, the two positive leads from the PV end up tying into a black wire, (can I assume it goes to PV- on the SCC, and the two negative leads from the PV end up tying into a red wire (positive to SCC)? Does this look correct? My guess is that there is a mistake in this diagram, maybe lost in the translation..... lol.

Or do I need to totally ignore the Gender, red o-ring and wire insulation color altogether as long as I know Neg to Neg and Pos to Pos? I am just about to forego this solar project.

 

[Exit_1831]

Are you referring to the red O-ring on what appears to be the male MC4 connector? That connector is actually the female connector. And yes, ignore the O-ring color. There is an "industry" standard is so far as the positive/negative connector types from a panel. I don't recall what that is off the top of my head. I don't trust the "industry" standard. To positively determine the positive and negative connectors on a panel use a multi-meter. Set the voltage to DC. Put the positive lead from your meter into one connector and the negative lead into the other connector. If you see a negative reading on the meter, your positive lead from your meter is in negative connector. Reverse your leads into the connectors. You should see a positive reading. This indicates that your positive lead from your meter is inserted into the positive connector. You can then, according to your drawing, hook up your Y connectors accordingly.

Hope this helps.
Ed

 

[sunshine_eggo]

The MC4 are marked with their polarity from the source.




The connectors from the panels are reversed in the diagram.

Always good to confirm with a meter.

 

[Quattrohead]

Always good to confirm with a meter.

ALWAYS.