In the United States, home outlets support a standard 15 amps, but you can upgrade per outlet if necessary. Most single-family residential homes have a maximum overall amp rating, usually 100 to 200 amps. Very old houses may have less than 100 amps, but that’s rare. Large homes often come with amp services above 200 amps to support modern lifestyles.

A voltmeter measures the voltage of AC or DC electrical current. Unlike a multimeter, measuring voltage is a voltmeter’s only function. Voltage is the potential difference between two points within a circuit. Measuring voltage with a voltmeter can help identify wiring issues or determine whether a battery is dead.

If you’re moving wires, installing new wires, or installing new fixtures in the space you’re insulating, then you will need to hire a licensed electrician to do that portion of the job for you. However, if you just intend on replacing old insulation or adding new insulation over existing insulation, then you don’t need to hire one. Your insulation installer will work around wiring, fixtures, outlets, and switches, even if they’re installing fiberglass batts in the voids where wires run. However, you will need an electrician if you suspect a problem with your wiring during the insulation work.

There are many signs it is time to replace an electrical panel, starting with flickering lights. Other tell-tale signals include overheating appliances, light fixtures that cause an electric shock, hissing or crackling from the breaker box, burned or blackened spots near the breaker box, and breakers that trip whenever activating power-hungry appliances like microwaves.