Using the KAIWEETS KM117B Socket Tester (the one @erik_squires linked), I took some measurements around my home:
My pizza oven consumes 11.5 amps during operation (measured using my
Amprobe ACD-10 TRMS-PLUS meter). With the oven off, AC volts available at the outlet is 121.3 - 121.5. With the oven on, volts available at the outlet dropped to 117.8. N-E volts 00 with the oven on or off.
My microwave oven consumes 14.6 amps during operation (measured using the amprobe meter). Volts available at the outlet with the microwave off was between 121.3 - 121.5. Volts available at the outlet with the microwave on was 117.9. N-E volts 00 with the microwave on or off.
My main audio system is a 3 power amp tri-amped system. The power amps alone consume about 1.5 amps total powered on with no program material. AC volts at the outlet is 121.5 with the amps off. With the amps on, volts at the outlet are 121.0. Peak amps measured at loudest passage was 1.9 amps (or, 0.40 amps above powered up status). The feed is 15' of 10 AWG directly from the circuit breaker box. N-E volts was 00 with the amps on or off.
My furnace consumes 3.79 amps with the unit in full operation (gas burner heating, and forced air fan blowing). Volts available at the outlet with the furnace off was 121.5. Volts available with the furnace full on was 120.5. N-E volts was 00 with the furnace on or off.
What this does prove to me is how important a dedicated run *is* for power amps, or high current consuming integrated amps or receivers.