The HMM1 Series MCCB is a high-performance "plastic shell" circuit breaker designed for reliable protection in low-voltage distribution systems. Engineered for AC 50/60Hz networks with rated voltages up to 690V, it serves as the primary defense against overloads and short-circuits in industrial and commercial installations.

From the compact 125A frame to the heavy-duty 800A unit, the HMM1 series is built with arc-extinguishing technology and high-grade flame-retardant materials. Whether you are protecting an industrial motor or managing a building's main distribution panel, this breaker ensures stable operation and rapid fault isolation to prevent equipment damage and downtime.

MCCB Moulded Case Circuit Breaker

HMM1 plastic shell type circuit breaker, suitable for AC 50HZ, rated voltage 690V, rated working current from 63A to 800A distribution network circuit, used to distribute power and protect lines and power equipment from overload, short circuit, undervoltage and other faults damage. At the same time, it can also be used as the motor's infrequent start and overload, short circuit, undervoltage protection.

HMM1 circuit breaker has the characteristics of small size, high breaking capacity, short fly-arc, beautiful appearance, can be installed vertically, can also be installed horizontally, but also has the isolation function, is a user's favorite product.

• Robust Arc-Extinguishing System: Utilizes a specialized grid-type arc chute to rapidly split and quench electrical arcs, significantly reducing contact erosion and increasing the life of the breaker.

• High Short-Circuit Breaking Capacity (Icu): Designed to handle massive fault currents (up to 65kA or more depending on the frame size), providing a high safety margin for critical infrastructure.

• Thermo-Magnetic & Adjustable Trip: Features reliable thermal-magnetic protection. Higher frame sizes offer adjustable settings to coordinate perfectly with downstream breakers and load profiles.

• Durable Engineering Plastics: The "plastic shell" is molded from high-strength, heat-resistant BMC/DMC material, providing excellent insulation and impact resistance in harsh industrial environments.

• Compact & Modular Footprint: Optimized dimensions allow for high-density installation in distribution boards, saving valuable panel space while maintaining required safety clearances.

1. Industrial Power Distribution: Main incoming breaker for factories, workshops, and automated production lines.

2. Motor Protection: Providing short-circuit and overload backup for high-power industrial motors and pumps.

3. Commercial Buildings: Primary circuit protection for shopping malls, office towers, and hospitals.

4. Infrastructure & Data Centers: Reliable power management in environments where service continuity is paramount.

• Silver-Alloy Contacts: Every breaker is equipped with premium silver-graphite alloy contacts to ensure low contact resistance and prevent welding during high-fault events.

• Accessory Flexibility: Can be easily customized with auxiliary contacts, alarm switches, shunt trips (MX), and under-voltage releases (MN) for integrated remote control.

• Rigorous Quality Testing: Every unit undergoes insulation, mechanical life, and thermal-trip testing before leaving the factory to ensure 100% field reliability.

• Easy Installation: Features heavy-duty terminal lugs compatible with both copper busbars and cable lugs, ensuring a secure and vibration-resistant connection.

Q: What is the difference between Icu and Ics for this MCCB?

A: Icu is the ultimate short-circuit breaking capacity (the maximum fault the breaker can survive), while Ics is the service breaking capacity. The HMM1 series maintains a high Ics/Icu ratio, ensuring the breaker can continue to operate reliably even after clearing a significant fault.

Q: Can this breaker be used for DC applications?

A: The HMM1 series is primarily designed for AC distribution. For DC applications (such as solar or battery storage), we recommend our specialized DC MCCB range with magnetic blow-outs.

Q: Do you offer the rotary handle for through-door operation?

A: Yes. We provide optional extended rotary handles and motorized operating mechanisms for customers who need to operate the breaker without opening the cabinet door.