One pair of MC4 2 to 1 parallel Branch Connectors (also known as ‘T’ or Y-connectors) for solar panels. Includes both MMF and FFFM. Used for parallel connection between panels or series strings while maintaining the voltage of your panel configuration.
MC4 Parallel Branch Connector Specifications
- Compatible Solar Cable: 14/12/10 AWG (2.4/4.0/6.0mm2)
- Maximum Voltage: 1500V
- Maximum Current: 50A
- Insulation Material: PPO
- Contact Material: Silver plated copper
- Contact Resistance: Less than 0.5m ohm
- Operating Temperature: -40°C to 125°C (-40°F to 257°F)
- Protection Rating: IP67
IMPORTANT NOTES REGARDING PARALLEL COMBINING
Normally combining two modules, or two series strings of modules, using these parallel branch connectors is fine. The rule of thumb is that 3 strings or more being combined in parallel will require overcurrent (fuse/breaker) on each string.
So, those 5-to-1 combiners you see on Amazon? They are NOT looking out for your system’s health! You can damage your solar modules, or worse.
Here is a quick explanation of the reasons why…
Check your solar module ‘max series string fuse’ specification
If your modules have a max series string fuse specification that is less than the sum of the amperages you are combining, then do not use this product.
You will need to use a combiner with overcurrent protection (ie fuses or breakers)
If your modules have a max series fuse rating of 15A
Module max output of 8A (Isc)
Combining two strings = 16A
Since this is greater than the 15A max series string spec, you will need to fuse/breaker each string when you parallel combine.
The reason is that if there was a fault in the module/string, it might result in the other string having to carry all the amperage of both strings.
Check Your Source
Some cheap Amazon and Alibaba shops sell strange Y-Connectors and Knock-off adaptors, and they don’t always have voltage or amperage capacity that is appropriate. If they don’t specify, then don’t buy! It’s simply not worth it to install an unreliable piece of electrical equipment.