FUJI ELECTRIC EGG06-04.SIG01

Overview

FUJI ELECTRIC EGG06-04.SIG01 is a Fuji Electric electronic trip unit with LSIG protection function for Fuji molded case circuit breaker (MCCB). EGG06-04 is the base part identifier, SIG01 denotes the LSIG configuration variant with long-time, short-time delay, instantaneous and ground fault protection. FUJI ELECTRIC EGG06-04.SIG01 is a field-replaceable solid-state release assembly, widely supplied as exchange spare for Fuji LV distribution switchgear overhaul and feeder breaker maintenance.

Features

FUJI ELECTRIC EGG06-04.SIG01 implements full LSIG protection: L long-time overload, S short-time delayed short-circuit, I instantaneous short-circuit, G residual ground fault protection. Thresholds and time bands are adjustable by local rotary switches or DIP settings for selective coordination between upstream and downstream protective devices. FUJI ELECTRIC EGG06-04.SIG01 is self-powered from the breaker built-in current transformers, so protection action remains available even without external auxiliary power supply. It supports internal hardware self-diagnosis for CT loop disconnection and electronic anomaly, reducing the risk of missing faults or nuisance tripping. FUJI ELECTRIC EGG06-04.SIG01 can work with breaker auxiliary and alarm switches to send trip status and fault alarm signals to PLC and SCADA for sequence-of-event logging. Compared with basic LI or LSI Fuji trip units, this variant adds ground fault protection for earth leakage and insulation failure risk mitigation. It complies with IEC and JIS standards for low-voltage power distribution equipment.

Specs

FUJI ELECTRIC EGG06-04.SIG01 Trip type: electronic solid-state release. Protection function: LSIG. Power supply: CT self-powered. Setting method: local hardware adjustment. Compatibility: matched Fuji MCCB frame with integrated CT sensors. This trip unit is not a complete circuit breaker and must be installed inside the corresponding breaker housing. FUJI ELECTRIC EGG06-04.SIG01 is widely supplied as service replacement spare for industrial, water treatment and general distribution cabinet maintenance.

Principle

FUJI ELECTRIC EGG06-04.SIG01 continuously samples phase current and residual ground fault current from the breaker CT assembly. The internal microprocessor calculates thermal accumulation for overload and compares fault magnitude against preset LSIG thresholds. When the measured value exceeds the configured limit, the trip unit triggers the breaker mechanical release mechanism to separate main contacts and isolate the fault circuit. The ground fault function of FUJI ELECTRIC EGG06-04.SIG01 detects residual unbalanced current caused by insulation degradation to protect personnel and equipment. Trip events are signaled through breaker auxiliary contacts for remote alarm and troubleshooting.

Applications

FUJI ELECTRIC EGG06-04.SIG01 is deployed for main incoming, bus tie, pump and large feeder MCCB protection in industrial plants, water treatment facilities and commercial low-voltage distribution switchgear. It is selected for spare inventory and breaker retrofit projects requiring LSIG selective protection and ground fault supervision for Fuji MCCB systems.