MC4 extension cables and polarity

[ToddParker]

Hi all.

Sorry if an obvious answer but most solar panels have a ‘male’ MC4 output for positive and ‘female’ for negative. The adapters that come with most power stations that convert MC4 to 8mm/XT60/etc. are set up with the opposite so the polarity is all good: ‘female’ for positive and ‘male’ for negative:

Solar Adapter
+ M —— F +
- F —— F -

If I need a longer run, I have MC4 extension cables but if you wire them up to a solar panel you end up with the male and female being opposite for what you need for the adaptor. I you hook them up the way the cables fit the polarity would be reversed.

Solar Extension Adapter
+ M —— F + —— F+ (Won’t connect)
- F —— F - —— F- (Won’t connect)

So how do people deal with this situation? I could add a second extension cable to get the connectors back to where they need to be but that’s a waste. Is there a male to female adaptor you use in these situations?

Thanks!

 

[Ampster]

I am not sure I understand your diagram and why there is even a question? All the extensions I have purchased are male on one end and female on the other. That way if you plug an extension into a male there is a male at the end. Similarly if you plu an extension into a female there will be a female at the end. Extensions are never the same on each end or the polarity would be reversed.

 

[ToddParker]

Thanks for the reply, maybe I was just confusing myself. You’re right.

 

[Bud Martin]

If you look at the electrical terminal inside the MC4 connector, you will see that the MC4 connector on the positive wire of the panel may look like a male plug because how the body is shaped but it is actually a female because the electrical terminal inside is Female electrical terminal, if you look at the MC4 connector on the Negative wire of the PV panel, you will see male electrical terminal inside.
The:
Solar Adapter
+ M —— F +
- F —— F -
May be you should show the pictures, it does not make any sense.

Solar Extension Adapter
+ M —— F + —— F+ (Won’t connect)
- F —— F - —— F- (Won’t connect)
It makes no sense either.

 

[time2roll]

I cut my extension in half and connected the bare wire to the screw terminals.

 

[SandyMcC]

There seems to be lots of confusion everywhere!
I looked up the datasheet for my REC solar panels and the picture below is a screenshot of the relevant area.
They use the convention that the positive (live) connector is the male plastic prong (with the
female metal connector inside).

Really male and female in the case of MC4 are very confusing, so a picture is a better method.

I will remember PPP = Plastic-Prong-Positive.

Has anybody found PV panels that use the opposite convention?

 

[Ampster]

I will remember PPP = Plastic-Prong-Positive.

Has anybody found PV panels that use the opposite convention?

No, I have not. I do like your PPP to remember.

 

[Zil]

I have Renogy Panels, with MC4. I have MC4 extension cables from Windy Nation. I did not have such a problem. The problem I had was the Renogy MC4 are special size and Windy Nation fixed me up.