Eaton NZMS6-100/ZM6-100 Molded Case Circuit Breaker

The NZMS6-100/ZM6-100 is a fixed-type molded case circuit breaker from Eaton's NZM series, designed for reliable protection of electrical installations against overload and short-circuit currents. The combination NZMS6-100 (breaker) with ZM6-100 (typically a rotary handle or accessory) offers a complete switching and protection solution.

Protection Characteristics

This MCCB features a thermal-magnetic trip unit. The thermal element (bimetal) provides inverse time-delay overload protection, adjustable from 80A to 100A (via a dial). The magnetic element offers fixed instantaneous short-circuit protection, typically set at 10 times In (1000A ±20%). This characteristic ensures coordination with downstream devices and selectivity.

Breaking Capacity and Electrical Data

The NZMS6-100 has a high breaking capacity according to IEC 60947-2: Icu = 36kA at 415V AC, 50/60Hz. It is rated for operational voltage up to 690V AC and insulation voltage 1000V. The breaker is suitable for isolation (isolating function) with visible contact indication. Rated frequency 50/60 Hz.

Construction and Terminals

The molded case is made of glass-fiber reinforced polyamide, providing high mechanical strength and dielectric properties. Main contacts are silver-alloy with arc runners and arc chutes for effective arc extinction. Terminals accept copper or aluminum cables up to 70mm², with box-type lugs for secure connections. The breaker is available in 3-pole configuration; the ZM6-100 accessory may include a rotary handle, shaft, or extended terminal cover.

Mounting and Accessories

Designed for fixed mounting, the NZMS6-100 can be installed on a mounting plate or in distribution panels. The ZM6-100 handle mechanism allows external operation with door interlock capability. Additional accessories include auxiliary switches (for remote status indication), shunt trips, undervoltage releases, and motor operators. All accessories can be field-installed without tools.

Environmental Conditions

The circuit breaker operates in ambient temperatures from -25°C to +70°C (with derating above 40°C). It is vibration-resistant and meets shock tests. The enclosure provides IP20 protection for the terminals (IP40 on the front when the rotary handle is installed). It complies with pollution degree 3 environments.

Applications

Common applications include main distribution boards, sub-distribution, motor control centers, and industrial machinery. The NZM series is widely used in commercial buildings, infrastructure, and heavy industry. The combination with ZM6-100 enhances safety with a door interlock and clear ON/OFF indication.