Connect hot and neutral wires correctly
If you wonder why you have to identify and connect the hot and neutral wires correctly in a lamp, read on. True, the lamp will usually work either way. But the issue is safety. Normally, power
(voltage) comes through the tab
on the socket base. The threaded socket
is the neutral. So when the switch is off,
all “hot” parts of the lamp are well protected.
And when the switch is on, only
the tab at the bottom of the socket is
“hot.” But if the wiring is reversed and the
power goes to the threaded socket, the
threaded socket is
always hot, whether
the switch is on or off. There's a much
greater potential for getting a dangerous
shock, especially when changing a bulb.
The worst situation occasionally occurs
in old fixtures when the cardboard insulation
sleeve wears out and the outer
metal shell of the socket touches the
threaded socket. If the threaded socket is
hot, every metallic part of the lamp
becomes hot! Remember when repairing
lamps, the neutral wire in the lamp
cord is marked (usually with a rib or
ribs) and it connects to the wide blade of
the plug at one end and to the neutral
screw (usually silver but may have some
other identification) at the other end.
Correct lamp switch wiring
Hot and Neutral Electrical Paths in a Lamp Switch and Socket
The hot path for electricity should run through the narrow plug prong at the wall outlet to the hot terminal on the switch and to the hot button at the base of the socket when the switch is on. The neutral path should run from the wide prong at the wall outlet through a marked (insulation) wire to the neutral terminal on the switch and to the threaded metal bulb socket.
