All electrical wire splices need to be protected inside an electrical box. This box must be mounted in a place that is accessible for future maintenance and inspection. Choose an electrical box that suites the environment where the box will be mounted. A 6/2 gauge wire has two conductors which need to be isolated from each other for the circuit to work. An insulated set screw butt splice is the right connector for this job.
Things You'll Need
Non-contact voltage detector
Insulated set screw butt splices
Turn off the power to the circuit you are working on at the home's distribution panel. Confirm the power is off by touching a non-contact voltage detector to the wire's insulation.
Strip 3/8 inch of insulation off the end of the two conductors for each wire with wire strippers.
Insert each wire through a separate access hole in either side of the electrical box. Secure the wires in place by tightening the screws on the compression mechanism.
Insert one wire in each end of the insulated set screw butt splice. Tighten the two screws on the connection mechanism. Repeat this process to connect the other two wires.
Secure the electrical box's access door with the screws provided. Mount the box in a place that is both accessible and in a location that reduces the chances of mechanical damage.