Two types of lighting circuits exist, series and parallel. Recessed lighting systems should wire in a switch-operated parallel circuit. If one light bulb burns out in a parallel circuit, the rest of the light bulbs stay lit; if one light bulb burns out in a series circuit, then all of the light bulbs turn off. To understand a parallel lighting circuit, think of train tracks: Each rail represents a wire, and each tie represents a light bulb.
Turn off the recessed lighting circuit's circuit breaker. The proper circuit breaker should have a "Lighting" tag.
Remove 9 mm (3/8 inch) of the insulation from each wire in each wire set with wire strippers. Each recessed light has two wire sets, except for the last recessed light, which has one wire set leading to it. The wire sets contain two wires with insulation and one wire without.
Open the recessed lights' electrical boxes with the correct type of screwdriver, often a 6 mm (1/4 inch) hex-head screwdriver. A recessed light's electrical box mounts to the top, or side, of the light's housing. and a flexible-metal conduit connects the box to the housing.
Pry a knockout, which looks like a metal disk, off each electrical box with a flathead screwdriver. A knockout, found on the side of the electrical box, provides a way for the wire set to enter the electrical box.
Insert the threaded end of a wire clamp into a knockout's hole and spin the wire clamp's locking nut onto the threads from inside the electrical box. Push on the locking nut's tabs with a flathead screwdriver to tighten it. Repeat this for each recessed light.
Push the last 10 cm (4 inches) of each wire set into its respective recessed-light electrical box through the wire clamp. Tighten the screws that push the wire clamp's clamp against the wire sets.
Twist the recessed light's green-coloured ground wire around the wire sets' uninsulated wires and spin a wire nut over them. Repeat this in each recessed light's electrical box.
Twist the recessed light's black-coloured wire around the wire sets' black-coloured wires and spin a wire nut over them. Repeat this in each recessed light's electrical box.
Twist the recessed light's white-coloured wire around the wire sets' white-coloured wires and spin a wire nut over them. Repeat this in each recessed light's electrical box.
Close the electrical boxes' covers before turning on the recessed lighting system's circuit breaker.