108 PCWorld NOVEMBER 2019HERE’S HOW INSTALL A SMARTWATCH
the junction box is the best way to confirm
that electricity is not flowing to the switch.
The battery-powered tool should beep and
light up if it detects current. If there’s more
than one switch in the box, make sure they
also don’t have electricity flowing to them.
Once you’ve confirmed that the power is
off, remove the screws holding the switch to
the junction box and pull it out so you can
access the electrical wires. Most smart
switches require four wires to operate,
including a “neutral” wire which should be
colored white or gray. The neutral wire
carries power back to the circuit breaker
panel to complete the circuit, so despite its
innocuous-sounding name, an electrified
neutral can shock you if current is flowing
through it. If your wiring doesn’t include a
neutral wire, your choice of smart switch will
be limited (more on that in a bit).
The “line” wire that carries power from
the breaker panel to the switch will
customarily be colored black, red, or blue.
The “load” wire carries electricity to the
socket (and by
extension, to the
bulb) and will typically
be colored white or
gray, like the line wire.
The final wire,
protective ground,
will be either a bare
wire or a wire in a
green jacket. Theground wire will prevent you from getting
shocked if there’s a short circuit.
If your home lacks a ground wire, you
might not be able to install a smart switch,
although there are various workarounds that
we won’t get into here. If your home lacks a
neutral wire, you might consider installing a
Lutron Caséta smart dimmer (go.pcworld.
com/ltrn), as it does not require a neutral
wire to operate.INSTALLING A
SMART SWITCH
Now that you’ve determined your home’s
wiring situation and purchased a smart
switch or dimmer, you’re ready to install it.
Once again, make sure you’ve turned off the
power to the switch. It’s always a good idea
to double-check that the power to the
switch is still off using the voltage tester.
Disconnect your old switch from your
home’s wiring. You might need to snip and
strip off about a half inch of the wire sheath
to expose the copper wire underneath. YouDisconnect your old switch from your home’s wiring. The C by GE smart
switch we’re installing uses pigtail wires; other switches have screw
terminals and still others rely on backstabs.