All
those electrical devices in your house require an unbroken supply of
power from your utility company. Here are the basic tests you may need
to conduct if you run into an interruption in power or an appliance
stops working.
Reset a circuit breaker
Steps:
1. When a circuit breaker trips, it moves about midway between the
full-on and full-off positions, and it will move back and forth a little
when you wiggle it.
2. To reset a tripped breaker, push it to the full-off position
(opposite all the other breakers in its column), then to the full-on
position, and then let go immediately. If it trips again or does not
stay in the On position, push it to the full-off position and tape it
over until you've resolved whatever's causing it to trip.
Test a live receptacle
Steps:
1. Plug the two probes of a continuity tester into the two vertical
slots. If there is power, the tester will glow. Test both halves. Some
receptacles are powered by two separate circuits.
2. Alternatively, plug a neon tester into the receptacle. It analyzes
the wiring, and its lights identify the problem.
Test for power at an open outlet box
Steps:
1. Shut off power to the circuit at the service panel. Remove the outlet
cover and remove the device (a switch or receptacle), or bend out the
connected wires and keep the ends apart.
2. Test a device by probing each terminal screw with one lead from a
neon tester and probing a metal outlet box or bare grounding wire with
the other lead.
3. Test connected wires by removing the wire nut enough to expose bare
wire, then probing that wire and either a metal outlet box or the bare
grounding wire. Repeat the process for every wire connection.
Test a device for continuity
Steps:
1. Make sure the wire or device isn't live. Use a neon tester on wiring,
or unplug or disconnect a device.
2. Clip one lead onto one terminal of a switch, for example, and probe
the other terminal. The tester should light with the switch in the On
position and, just as important, should not light in the Off position.
Overall Tips:
Test a continuity tester's battery and bulb by touching the probe and
clip together momentarily. The bulb should light.
A circuit breaker may have a red indicator that signals it has been
tripped.
Overall Warnings:
If a breaker tripped due to a tool or machinery overload, make sure
you've switched off or unplugged that tool before restoring power.
Never use a continuity tester until you have verified that there's no
current in the line.
If you know of or suspect an unresolved problem that has caused the
breaker to trip, do not attempt to reset it until you've investigated
and corrected the situation.
PROBLEMS - POSSIBLE CAUSES AND SOLUTIONS
Plugged-in device not working. If device is light fixture, bulb may be
out Replace bulb with working one or test suspect bulb in working lamp.
Faulty device. Test device in working receptacle. If it works, test for
power. If not, inspect the plug, cord, switch, internal wiring
connections, fuses, safety shutoff or reset button, other electrical
contacts.
No power at receptacle. Test receptacle with neon tester by inserting
probes into two receptacle slots. Light should glow.
Hard-wired device not working. No power coming into outlet. Test for power
at problem outlet; inspect previous (upstream) outlet for faulty or
loose connections (only if series wiring).
Faulty or improper wiring connections within outlet box. Shut power to
circuit and access outlet for inspection. Verify that connections are
properly made and tight.
Wall switch off faulty or has faulty wiring. Make sure wall switch,
timer or other control is on; turn power off to inspect connections;
remove switch to test continuity.
Faulty device. If outlet is powered, unplug device to inspect, as
applies, for problems in its switch, internal wiring connections,
internal fuses, safety shutoff or reset button, other electrical
contacts.
No power in entire house. Off-premises power failure Contact power
company or neighbors.
Main circuit breaker tripped or fuse blown. At the main service panel,
see if main breaker has tripped or remove and test main fuse.
No power in particular circuit. Branch circuit breaker tripped or fuse
blown Resolve known cause and reset circuit.
No power in half of duplex receptacle. That half is wall-switched If
there is a switch, verify that it's on and that connections are tight.
Test switch with continuity tester.
Link between two halves removed. Remove receptacle to determine if two
silver terminals and two brass terminals are connected.
