50A MC4 Y-Splitters?

[fafrd]

I’m putting together a small 3-panel 1350W off-grid PV system and am planning to connect the three panels together with a Y-splitter feeding an 8AWG run to the charge controller, with first fusing there.

I’ve found 8AWG PV wire with 50A MC4 connectors on them but every Y-splitter connectorI’ve found is only rated for 30A.

Does anyone have a source for 2-1 or 3-1 MC4 Y-connectors rated for 50A?

Ioc on my panels is 11.5A so a short on the home run can draw 34.5A and while the 8AWG wire and it’s straight connector will be OK with that current, I need 2 2-way or a single 3-way Y-connector that is also rated for over 30A in the case of a short.

I suppose if worse comes to worse I can join 3 30A wires/connectors to an 8AWG home run wire in a junction box, but I was hoping to find an easier plug-and-play solution.

 

[ghostwriter66]

I'm going to say with that amperage - best would be to tie them off together ---- they do make some Y connectors for 50A and higher BUT they are like $37.00 each -- and heavy -- ... I would just get the largest connection cap i could - or solder them - and be done ...

 

[fafrd]

I'm going to say with that amperage - best would be to tie them off together ---- they do make some Y connectors for 50A and higher BUT they are like $37.00 each -- and heavy -- ... I would just get the largest connection cap i could - or solder them - and be done ...

Interested to know understand what you mean by soldering and/or connection cap.

I’m hoping to have all MC4 connectors going into a final 8AWG MC4-connected home run cable pair.

I found these Y-connectors rated for 50A for $30 for 5: https://www.amazon.com/JHBOX-Branch-Connectors-Connector-mounts/dp/B081PMKZF1?th=1&psc=1

“The solar panel connectors have a maximum voltage of 1500VDC and a 50A rated current.”

I’m not going to be running 50A of current through these, but since they will be protected by a 50A fuse, want to be sure they are rated for that peak current.

The 450W panels I’m eyeing have an Imppt of 10.87A so the first Y-connector connected to 2 panels will have under 22A running through it at most under normal operating conditions and the second Y-connector tieing a 3rd panel to the string in parallel will have under 33A running through it under normal operating conditions.

Isc of these panels is 11.5A so in the case of a short in the 8AWG home run, there will be under 35A flowing through that second Y-connector. Even when applying the 125% rule I should be good with a 50A current rating.

Any shorts in a panel or the MC3 cables to the panels should never see over 23A of current (well-within the 30A rating of the 10AWG cables @ 125%).

This is my first time doing a DC-coupled solar build, so currents are quite a bit higher than I have experienced with my 4kW Microinverter 240VAC-coupled build, but it looks like a parallel string of 3 panels with MC4 connectors and an 8AWG home run protected by a 50A breaker fits the bill...

 

[ghostwriter66]

Interested to know understand what you mean by soldering and/or connection cap.

I’m hoping to have all MC4 connectors going into a final 8AWG MC4-connected home run cable pair.

I found these Y-connectors rated for 50A for $30 for 5: https://www.amazon.com/JHBOX-Branch-Connectors-Connector-mounts/dp/B081PMKZF1?th=1&psc=1

“The solar panel connectors have a maximum voltage of 1500VDC and a 50A rated current.”

I’m not going to be running 50A of current through these, but since they will be protected by a 50A fuse, want to be sure they are rated for that peak current.

The 450W panels I’m eyeing have an Imppt of 10.87A so the first Y-connector connected to 2 panels will have under 22A running through it at most under normal operating conditions and the second Y-connector tieing a 3rd panel to the string in parallel will have under 33A running through it under normal operating conditions.

Isc of these panels is 11.5A so in the case of a short in the 8AWG home run, there will be under 35A flowing through that second Y-connector. Even when applying the 125% rule I should be good with a 50A current rating.

Any shorts in a panel or the MC3 cables to the panels should never see over 23A of current (well-within the 30A rating of the 10AWG cables @ 125%).

This is my first time doing a DC-coupled solar build, so currents are quite a bit higher than I have experienced with my 4kW Microinverter 240VAC-coupled build, but it looks like a parallel string of 3 panels with MC4 connectors and an 8AWG home run protected by a 50A breaker fits the bill...

Those Amazon connectors look fine .... what i was saying that you could literally take something like a https://www.lowes.com/pd/Alumiconn-...WlXKUhU8BjiPOYfb7QoaAtlAEALw_wcB&gclsrc=aw.ds - connect the three wires to it and for like $6 do what Amazon wants for $30.00 --- not pretty but works well

 

[fafrd]

Those Amazon connectors look fine .... what i was saying that you could literally take something like a https://www.lowes.com/pd/Alumiconn-...WlXKUhU8BjiPOYfb7QoaAtlAEALw_wcB&gclsrc=aw.ds - connect the three wires to it and for like $6 do what Amazon wants for $30.00 --- not pretty but works well

Gotcha. That’s a nice product but it would mean cutting the MC4 connectors off if the panels or alternatively connecting 4 straight MC4 connectors to create a 3-to-1 MC4-compatible Y-connector.

If I knew that the reliability of a DIY Y-Connector based on one of these on the roof and under a panel would be as good as the reliability of an MC4 Y-Connector, I’d consider it, but looks like those junctions are going to be more exposed than the sealed junctions of an MC4 connector so I’m thinking it would be more prudent to reserve a junction block like this for indoor / dry use...

But thanks for the pointer - I hadn’t been aware of those economical junction blocks and I’m sure they’ll come in handy somewhere in my build.