What are the three types of overload relays?

Bimetallic overload relays are the most common type. They work by using two different metals that have different expansion rates. When the current flowing through the relay increases, the two metals heat up and expand at different rates. This causes the bimetallic strip to bend, which triggers the relay to trip. Eutectic overload relays use a eutectic alloy, which is an alloy that melts at a specific temperature. When the current flowing through the relay increases, the alloy’s temperature rises and melts. This triggers the relay to trip. Electronic overload relays use electronic components to detect an overload condition. These relays are typically more expensive than bimetallic or eutectic relays, but they offer more precise overload protection. The best type of overload relay for a particular application will depend on the specific requirements of the application.