ylikuormasuojia

Ylikuormasuoja, known in English as an overload protector or thermal overload relay, is a safety device designed to prevent damage to electrical equipment from excessive current. This device detects when a motor or other electrical load is drawing more current than it is designed to handle, which can be caused by issues such as mechanical overload, a locked rotor, or single-phasing. When the overcurrent condition persists for a specific duration, the ylikuormasuoja trips, interrupting the power supply to the equipment.

There are several types of ylikuormasuoja. Bimetallic overload protectors are common, utilizing two different metals with varying thermal expansion rates. As current flows through a heating element, it heats the bimetallic strip, causing it to bend. Once the bending reaches a certain point, it triggers a mechanism to open the circuit. Other types include electronic overload protectors, which use solid-state circuitry to monitor current and temperature, offering more precise and adjustable protection.

The primary function of a ylikuormasuoja is to protect motors from overheating, which can lead to insulation breakdown and permanent damage. By preventing sustained overcurrents, these devices extend the lifespan of electrical equipment and enhance operational safety. They are typically installed in series with the motor's power circuit and can be reset manually or automatically after the fault condition has been cleared. Proper selection and setting of the ylikuormasuoja are crucial for effective protection.