Current is expressed as the electrical charge passing through a wire over time. Alternating current has a harmonic sinusoidal waveform.
Maximum current in electrical sockets
The maximum current that can be drawn from a wall socket is different for different types (in different countries).
In Europe, synchronous 230V / 50Hz grid is used. Single-phase sockets are rated for 230V / max 10 to 16A.
In North America, households are supplied with 120V / max 15A, 60Hz.
Limiting the maximum current
The current flowing through a circuit varies according to the consumption of the connected appliance. When the current is too high (or there is a short circuit), circuit breaker disconnects the entire circuit.
When only one appliance is connected to the socket, the waveform of the current drawn can be analyzed to determine the appliance’s behavior.
In the context of NETIO products
NETIO smart sockets measure the AC current [A] as a single RMS value for each measured channel separately.
For instance, PowerPDU 4C has 4 output electrical sockets and measures 4x electrical current per socket + one overall value.