Product Overview

Ring Main Unit C-GIS Three-Phase The three-phase CT is full-enclosed in the flame retardant plastic shells, primary bushing or cable can pass through the inner hole, bottom has installation inserts for fixation. It is simple and shortcut, is suitable for measuring current, signal collection and protective relaying in the medium voltage power system of bushing or cable etc

Key Features

• Integrated Three-Phase & Zero-Sequence Current Measurement：Designed for three-phase bushings in ring main units and pole-mounted switches, enabling simultaneous precise measurement and reliable protection for both three-phase and zero-sequence currents. Ideal for multi-cable loop applications, providing comprehensive monitoring for power systems.

• High-Reliability Fully Sealed Structure：Core and secondary windings are vacuum-cast with premium epoxy resin into a flame-retardant plastic housing, forming a hermetic seal. Resistant to moisture ingress, ensuring stable performance and maintenance-free operation throughout the lifecycle, minimizing O&M costs and potential failures.

• Wide Range of Ratios & High-Precision Output：Covers ratios from 75/5 to 800/5, meeting diverse requirements of different power systems and equipment. Classified into multiple types based on ratio, accuracy class, and rated burden. Measurement winding achieves 0.2S accuracy with ≤0.2% ratio error and ≤10' phase displacement from 1%–120% of rated current, ensuring precise metering.

• Excellent Electrical Performance & Stability：Supports 50Hz/60Hz rated frequency for global compatibility. Secondary current options of 5A/1A for seamless integration with measuring and protection devices. Withstands short-time thermal current up to 40kA/1S and continuous thermal current of 1200% In. Load power factor COS&phi;=0.8 (lagging), instrument security factor (lateral) FS<10, and protection accuracy limit factor up to 10P10/15/20, ensuring reliable operation under complex conditions.

Technical Data

• Rated secondary current: 5A,1A

• Power frequency withstand voltage:3kV

• Rated frequency:   50/60Hz

• Installation site: Indoor

• Technical standard:  IEC 60044-1

Specification