MERLIN GERIN NS800H

Overview

MERLIN GERIN NS800H (Schneider Electric ComPacT NS series, legacy Merlin Gerin branding) is a high-performance moulded case circuit breaker (MCCB), 800A frame size, H breaking capacity grade. It is fitted with MicroLogic electronic trip units for adjustable overload, short-circuit and earth fault protection, widely supplied as exchange spare for main distribution panels, generator outgoing feeders, MCC cabinets and industrial power system overhaul and replacement.

Features

MERLIN GERIN NS800H supports interchangeable MicroLogic trip units: MicroLogic 2.0 (LI), MicroLogic 5.0 (LSI), MicroLogic 6.0 (LSIG with earth fault). Long-time overload pickup Ir, short-time delay Isd and instantaneous Ii are adjustable on the trip unit. The H grade provides 70 kA ultimate breaking capacity Icu at 415 VAC for heavy fault level applications. It supports isolation function complying with IEC 60947-2 and utilisation category B.

MERLIN GERIN NS800H accepts a wide range of field accessories: auxiliary contact, fault alarm contact, shunt release, undervoltage release, motor operator, rotary handle and extended terminal shields. It can be supplied as fixed type or plug-in type for easy removal without de-energising upstream. The electronic trip unit provides metering of current, power and energy, alarm pre-warning and fault memory for maintenance review. It complies with IEC, CE and marine EMC standards.

Specs

MERLIN GERIN NS800HPlatform: Merlin Gerin ComPacT NS series Type: MCCB moulded case circuit breaker Model: NS800H Rated current In: 800 A Rated operational voltage Ue: up to 690 VAC Breaking capacity Icu: 70 kA @ 415 VAC Trip unit options: MicroLogic 2.0 / 5.0 / 6.0 Poles: 3P / 4P Mounting: fixed or plug-in base Protection rating: IP20 (breaker body) This is not an air circuit breaker, contactor or relay; it is a large-frame electronic-trip MCCB for low-voltage power distribution protection. MERLIN GERIN NS800H is widely supplied as service replacement spare for main power distribution feeder protection failure.

Principle

MERLIN GERIN NS800H samples phase current via built-in current transformers feeding the MicroLogic electronic trip unit. The controller compares measured current against the configured Ir, Isd and Ii thresholds. If overload persists, long-time delayed tripping activates; short-circuit triggers short-time delay or instantaneous trip. LSIG variant monitors residual current for earth fault protection. Once tripped, the mechanical contact mechanism opens the main contacts and stores fault indication.

Applications

MERLIN GERIN NS800H is deployed for LV main switchboards, diesel generator output circuits, large motor feeders and process plant distribution. It is selected for spare inventory and power panel retrofit projects for existing Merlin Gerin ComPacT NS distribution systems.