How 240 Volt Power Works
- Traditionally, 240-volt circuits used three wires, two of which were live and the other neutral. Recent installations, however, use four wires -- the extra wire is used for grounding -- to comply with building codes.
- According to Ohm's Law, the power of an electrical circuit can be calculated by multiplying the voltage in the circuit, in volts (V), by the current, in amperes (A). The higher voltage of a 240-volt supply means that the same level of power can be achieved with lower current -- and therefore smaller wire -- than a 120-volt supply.
- A 240-volt power supply represents a significant shock hazard. A 240-volt shock can result in death or serious injury, so the supply should be switched off and locked out when working with any 240-volt circuitry or appliance.
