GE (Vernova) SG34NAT400F

Overview

GE SG34NAT400F is a 3-pole 400A molded case circuit breaker from the legacy GE Spectra RMS SG frame series for ANSI low voltage distribution systems. SG denotes the SG frame platform, 3 means 3-pole, 400 is the 400A rated sensor size, NAT indicates the trip unit configuration with adjustable long-time, short-time delay and instantaneous protection. GE SG34NAT400F is end-of-life molded case hardware, widely supplied as exchange spare for industrial, water treatment and data center ANSI MCC panel overhaul and feeder replacement.

Features

GE SG34NAT400F adopts true RMS current sensing, which delivers accurate protection performance under harmonic distortion loads such as VFD and UPS non-linear feeders. The trip unit uses local rotary dial adjustment to set overload pickup, short-time delay band and instantaneous pickup for selective coordination between upstream and downstream protective devices. GE SG34NAT400F is self-powered from the built-in current transformers, so protection functions remain available without external control power supply. It supports add-on auxiliary switches and alarm contacts to send trip status and fault signals to PLC and SCADA sequence-of-event logging. GE SG34NAT400F can be fitted with optional shunt trip, undervoltage release and neutral/ground fault accessories according to site safety and interlock requirements. It complies with UL and ANSI standards for North American power distribution applications.

Specs

GE SG34NAT400F Frame: Spectra RMS SG. Pole: 3-pole. Rated current: 400A. Trip type: NAT adjustable LI/LSI solid-state RMS trip unit. Rated voltage: 480VAC class. Mounting: panel mount. Accessories: auxiliary switch, shunt trip, UV release, ground fault module (optional). GE SG34NAT400F is widely supplied as service replacement spare for main feeder and heavy motor circuits.

Principle

GE SG34NAT400F continuously samples phase current signals via internal CTs and calculates true RMS current value. The internal protection logic compares measured current against preset overload and short-circuit thresholds. When current exceeds the configured setting, the trip unit triggers the mechanical operating mechanism to open the main contacts and isolate the fault circuit. The RMS sensing technology of GE SG34NAT400F avoids protection misoperation caused by distorted current waveforms. Trip and alarm signals are transmitted through auxiliary contacts for remote monitoring and interlock.

Applications

GE SG34NAT400F is deployed for main incoming, bus tie, large pump, fan and compressor feeder protection in ANSI-spec industrial plants, commercial buildings, water treatment facilities and data center low voltage switchgear. It is selected for spare inventory and cabinet retrofit projects for existing Spectra RMS SG MCCB systems.