In electronics, derating is the operation of a device at less than its rated maximum capability in order to prolong its life. Typical examples include operation below the maximum power rating, current rating, or voltage rating.

What does derating mean in electrical terms?

Derating is a technique usually employed in electrical power and electronic devices, wherein the devices are operated at less than their rated maximum power dissipation, taking into account the case/body temperature, the ambient temperature and the type of cooling mechanism used.

What is the purpose of derating?

Derating increases the average strength, decreases the average stress, and decrease the stress variations. This extends the component's life in addition to enhancing the reliability. In power supply units, the derating is usually done in situations where operating temperatures are higher.