Final answer:
Selecting derated switches for known continuous load current applications ensures safety and reliability by choosing a switch with a higher rated capacity than the actual load to handle surges and prevent failure.
Step-by-step explanation:
The purpose of selecting derated switches for known continuous load current applications is to ensure reliability and safety. Derating a switch means choosing a switch that has a rated capacity higher than the actual continuous load it will carry. By doing so, the switch can handle temporary surges, prevent overheating, and reduce the likelihood of electrical failure.
For example, if a circuit is expected to carry 10 amps continuously, a switch rated for 15 or 20 amps may be selected. This buffer accommodates any unforeseen increase in current without compromising the switch's integrity or causing a safety hazard. The practice of derating is essential in electrical engineering to build systems that are both safe and durable, accommodating various potential electrical situations that may arise during the lifespan of the system.
For example, if a switch has a maximum current rating of 10A but will be used in a continuous load application that requires only 8A, it may be derated by selecting a switch with a rating of 6A or 7A to reduce stress and prevent overheating.
This practice is important because switches generate heat when current passes through them. Exceeding the rated current can cause excessive heating and may lead to the switch failing or becoming a safety hazard.