When making wiring for a new, powerful electrical appliance or assembling a switchboard in an apartment, you need to know the maximum current consumed by the device or on the line from the switchboard. This is necessary for the correct selection of the overload protection circuit breaker and wires according to the cross section. The calculator will help you calculate the current by power when working from a single-phase AC network.
To calculate the current strength, the formula is used:The formula uses the following values:
- P is power, W;
- U – voltage, V;
- Cos φ – power factor;
- I – current strength, A.
Of the presented values, there is a rare value – cosφ.
cosφ (“cosine phi”) is the ratio of active power to total power, characterizes the operation of alternating current and is a dimensionless quantity.
If you are unfamiliar with this setting, do not change the value.
Knowing the current strength consumed by the device allows you to determine which machine and wire to use in a given circuit.
For example, you installed a washing machine, and to connect it you want to run a separate wire with a separate circuit breaker on this line. Machine power 2,4 kW or 2400 watts.
The calculation of the current strength gave the result – 10.4 A. From here we get, we need:
- automatic machine with current section 16 A;
- cable with core cross section: copper – 1 mm2, aluminum – 2 mm2;
- sockets – 16 A.