The ESL-421 series microcomputer protection and measurement device is a new generation of digital protection and measurement device. Microcomputer protection is a relay protection composed of microcomputers and is the development direction of power system relay protection. It has high reliability, high selectivity, and high sensitivity. The hardware of the microcomputer protection device is centered around a microprocessor (microcontroller), equipped with auxiliary circuits such as input and output channels, human-machine interfaces, and communication interfaces, to achieve real-time monitoring and protection of the operation status of electrical equipment. The ESL-421 series is widely used in various industries such as power, petrochemicals, metallurgy, steel, building materials, municipal, railway, and civil construction.

The ESL-421 series protection is divided into 6 models, choose the corresponding model according to your needs.