Electrical Systems and Appliances
Safety and measurement
Electrical questions test safety first: de-energize, lock out and tag, then verify with a meter on the conductor you are about to touch; treat unknown wires as live. Know volts, amps, ohms, and watts, and the power equation W = V x A well enough to size a circuit. A 1,500-watt space heater on 120 volts draws 12.5 amps. Copper wire ampacity: 14 AWG is 15 amps, 12 AWG is 20 amps, 10 AWG is 30 amps. A breaker protects the wire, so never upsize a breaker to stop tripping.
Devices and protection
GFCI protection is required in bathrooms, kitchens, laundry areas, garages, basements, outdoors, and near sinks. One GFCI can protect receptacles downstream, so a dead bathroom outlet with the breaker on often means a tripped GFCI elsewhere. AFCI protection addresses arc faults. Grounding and polarity matter, and reversed polarity or an open ground are common inspection findings. Junction boxes must stay accessible and correctly sized.
Appliances
Read the nameplate for voltage and amperage, and remember that large appliances need dedicated circuits. Refrigerator not cooling: check power, condenser coils, door gaskets, and airflow. Garbage disposal hums but will not turn: cut power, then free the flywheel with the hex wrench. A dryer that needs two cycles usually has a clogged vent or lint path. Never use water on an electrical fire, and avoid extension cords as permanent wiring.
Worked example
A bathroom receptacle is dead but the breaker is on. Look for a tripped GFCI upstream, in the same bath, another bath, the garage, or at the panel, reset it, and retest. If it trips again, isolate the downstream load instead of replacing the device.