Protection function

▪ Three phase three-stage directional current protection (quick break, time limited quick break, overvoltage, inverse time limit) with composite voltage lockout function.

▪ PT disconnection lockout voltage protection

▪ Equipped with low current grounding line selection function

▪ Low voltage protection, voltage loss protection

▪ Low frequency load shedding protection for low-voltage locking and slip locking

▪ Overload protection (trip and alarm optional)

▪ Zero sequence overvoltage protection

▪ Zero sequence overcurrent protection (with optional tripping and alarm)

▪ Non electricity protection (heavy gas, light gas, over temperature, over temperature)

scope of application

This device is suitable for transformer protection with voltage levels of 66KV and below Suitable for protection and measurement of 10KV (6KV)/0.4KV distribution transformers and 66KV small capacity step-down transformers. Specially suitable for power systems, distribution in factories and mines, and distribution protection measurement and control in building systems. It can be centrally assembled into screens or installed on-site in switchgear, fully supporting the comprehensive automation system of substations.

Principle block diagram