MC4-T MC4-Y Solar Branch Connector for Two-String Parallels
Both parts in this family take one cable in and split it to two, which is how two strings of modules are paralleled before the home run reaches the combiner. The T version does it in a moulded tee body that mates with standard MC4 connectors. The Y version does it on a short lead with the split inside a sealed joint.
T Body or Y Lead
The T body plugs onto the string connectors and keeps the joint at the module rail, so there is no loose lead to tie down. The Y version puts the split on a lead, which takes the branch down the side of the array and keeps the footprint at the connector small. Both are supplied as a pair, one male input and one female input, so a two string parallel is one order line.
Two Ratings in One Family
The 30A build takes 2.5 to 6mm² cable at 1000V DC. The 45A build takes 4 to 6mm² at 1500V DC. The gland accepts a cable outer diameter of 4.5 to 8.5mm, so a double insulated PV cable lands without a shim. Choose the rating from the string current rather than from the module count.
Contact, Seal and Temperature
Contacts are tin plated copper at 1mΩ contact resistance, crimped rather than screwed. Insertion force is 50N or less and withdrawal force 50N or more, which is what keeps a mated pair together through thermal cycling. The body is PPO with a UL94-V0 flame class, sealed to IP67 when mated and IP2X on the open side. The pair is rated -40°C to +125°C and tested at 6000V for one minute.
Choosing Between the Two
Take the T body where the parallel happens at the last module of a row and the cable can stay on the rail. Take the Y lead where two rows meet at the end of an array and the joint has to sit away from the glass. Both are overvoltage category CAT III at pollution degree 2. Send your string current, cable size and quantity to WTAIELE for a quote.
