Description
MERLIN GERIN
MASTERPACT
NW20 H1
CIRCUIT BREAKER
2000A
UI: 1000V UIMP: 12KV
UE ICU
(V) (KA)
220/440 ~ 65
480/690 ~ 65
ICS = 100% ICU
ICW 65KA/1S CAT.B
IEC 60947-2 50/60 HZ
The Merlin Gerin Masterpact NW20 H1 is a high-capacity air circuit breaker rated at 2000A, designed for robust overcurrent and short-circuit protection within main and sub-main power distribution systems. As a Category B device compliant with IEC 60947-2, it is engineered to handle demanding electrical environments found aboard commercial and industrial vessels. In marine applications, air circuit breakers of this class are central to main switchboard and distribution panel assemblies, safeguarding propulsion, power generation, and critical load circuits from fault conditions that could compromise vessel operations.
Key Features
✓ Rated at 2000A continuous current with a maximum voltage UI of 1000V and impulse withstand voltage UIMP of 12kV, suitable for high-power marine distribution systems.
✓ Short-circuit breaking capacity (ICU) of 65kA at both 220/440V and 480/690V AC, with ICS equal to 100% ICU, confirming full rated service short-circuit capacity without derating.
✓ Short-time withstand current rating of 65kA for 1 second (ICW 65kA/1S), enabling selective coordination with downstream protective devices in tiered switchboard architectures.
✓ Compliant with IEC 60947-2 and rated for 50/60 Hz systems, making it compatible with the full range of international vessel electrical standards and shore-power configurations.
✓ Designed for installation in main switchboards and motor control centres; mounting configuration and auxiliary module compatibility subject to confirmation against vessel-specific panel drawings.
Marine Applications
✓ Main switchboard feeder protection on merchant vessels, offshore platforms, and large passenger ships where high fault-level ratings are essential.
✓ Power distribution panels protecting propulsion drive systems, bow thrusters, and high-load electrical consumers requiring reliable overcurrent isolation.
✓ Generator incomer protection in multi-generator configurations, supporting bus-tie and load-shedding schemes common in vessel power management systems.
✓ Emergency switchboard and essential services distribution where IEC 60947-2 Category B performance is required to meet class society and flag state installation standards.
✓ Retrofit and planned maintenance replacement in existing Masterpact NW-series panel assemblies aboard vessels with established Schneider Electric & Merlin Gerin electrical infrastructure.
Why Marine Engineers Choose
The Masterpact NW20 H1 is a well-established platform in marine power distribution, valued for its high interrupting capacity, full-rated service breaking performance, and compatibility with the widely deployed NW-series switchgear found across commercial fleets and offshore installations worldwide.
Ideal For
Bulk carriers, container vessels, tankers, offshore support vessels, platform supply vessels, cruise ships, ferries, and any vessel class requiring high-capacity IEC-compliant air circuit breaker protection within main or emergency switchboard systems.
Technical Support
Technical support is available for the Merlin Gerin Masterpact NW20 H1 air circuit breaker, covering onboard installation guidance, switchboard integration, and remote troubleshooting assistance. Support extends to repair queries and like-for-like replacement evaluation to assist marine electrical teams during scheduled maintenance or emergency spares sourcing.
