# Mall versus Home Electrocution (Updated) Source: https://www.youtube.com/watch?v=sWGUo_iiaZE Recap page: https://rapidrecap.app/video/sWGUo_iiaZE Generated: 2026-01-07T17:06:21.961+00:00 --- ## Quick Overview The voltage across parallel circuits remains constant regardless of the current drawn by other loads connected to the same source, meaning 120 volts from a breaker panel is electrically the same as 120 volts from an outlet, although high-energy switching inductors can introduce dangerous, momentary high-voltage spikes onto the line that are far more hazardous than the steady state voltage. **Key Points:** - The speaker refutes the claim that 120 volts in a breaker panel is "stronger" than 120 volts at an outlet, asserting that "120 volt is 120 volt" because voltage across parallel circuits remains the same. - An experiment demonstrated that a space heater drawing nearly 11 amps did not affect the current (around 12 milliamps) flowing through a parallel 10-kiloohm resistor connected to the same 120V line. - When drawing a large current load, the measured voltage dropped from 120 volts to 112 volts due to wire resistance/impedance, making the line "a little bit safer" momentarily. - Connecting and disconnecting an inductor caused significant, momentary voltage spikes reaching up to 500 volts on the 120-volt line, which are far more dangerous than the steady voltage. - The speaker suggests these high-voltage noise bursts from faulty equipment, like a cheap angle grinder with a brush DC motor on a long cord, could make an accidental shock much more painful and dangerous locally. - Normal consumer electronics and appliances must have proper filtering, and high-energy facilities use thick, low-resistance power cables that absorb this noise, meaning spikes are generally not a household problem. **Context:** The video addresses a common misconception regarding electrical safety, specifically whether the 120-volt supply originating from a main breaker panel is inherently more dangerous or 'stronger' than the 120-volt supply found at a standard wall outlet. The discussion centers on electrical principles, particularly how voltage and current interact in parallel circuits, and the potential for transient high-voltage events caused by specific types of loads like inductors. ## Detailed Analysis The core argument presented is that, fundamentally, 120 volts is 120 volts, irrespective of whether it powers an entire shopping mall or charges a phone; the voltage across the body determines the current that passes through it, not the total capacity of the source. The speaker proved this by running an 11-amp load (a space heater) parallel to a test resistor and confirming that the current through the resistor remained constant at about 12 milliamps, showing the high-current load did not affect the parallel circuit. Furthermore, the speaker noted that high current draw actually causes a slight voltage drop (from 120V to 112V) due to wire impedance, which slightly reduces the danger. However, the investigation revealed that certain loads, specifically switching an inductor, create large, high-frequency voltage spikes potentially reaching 500 volts. The speaker posits that these momentary, high-energy bursts, if not properly filtered as required by standards, are what can make an accidental shock significantly worse, especially if created locally by noisy devices like brush motors on long wires, where the line impedance allows the noise to propagate and become more dangerous. ### Voltage Equivalence Principle - 120V in a breaker panel equals 120V at an outlet - Current draw by one parallel circuit does not affect the voltage or current in another parallel circuit unless the source impedance causes a measurable voltage drop - Voltage dropped to 112V under an 11-amp load. ### Experimental Validation of Parallel Circuits - A space heater drawing nearly 11 amps was connected in parallel with a 10-kiloohm resistor; the resistor's current remained stable at approximately 12 milliamps, confirming external load current does not affect parallel paths. ### Transient Voltage Spikes from Inductive Loads - Switching an inductor on and off generated momentary voltage spikes up to 500 volts on the 120V line, demonstrating a significant potential hazard not related to steady-state voltage. ### Potential for Enhanced Danger - High-energy noise pulses from faulty equipment (like brush DC motors) on long wires might create dangerous, localized high-voltage conditions that could make accidental electrocution far worse than standard 120V exposure. ### Mitigation and Standards - Proper filtering is required for consumer electronics to prevent noise generation, and high-energy facilities use thick, low-impedance cables designed to absorb such electrical noise.