No-Load-Current

What is a No-Load Current?

If an electric device with no load is connected to the defined nominal voltage the no-load current flows. During the idle of a device a current may flow and lead to an unwanted energy loss

Areas of Application for No-Load Current

Idle in an Electric Engine

An electric machine (electric engine, actuator) uses energy for moving of its own components and the overcoming of friction and bearing resistance during idle. In coils additional iron losses appear as well as losses due to energizing the magnetic field. This current increases the use of energy of the application.

Idle in a Transformer

If the secondary side of a transformer is not under load by an electric consumer, the current flowing on the primary side is called no-load current. It depends on the manufacturing tolerances of the transformer core and may vary a lot. In comparison to the regular currant during full load on the secondary side the no-load current is very low. During idle tests only the no-load current is flowing through the coil subject to the test. During the test the iron loss of the transformer is calculated.

During idle the absorbed power usually is lost as waste heat. Idle losses therefore have to be kept as low a possible. Due to the separation in the network the no-load current is switched off and losses are avoided.