ZYHM1L Series Molded Case Circuit Breaker

Scope of Application
The ZYHM1L series molded case circuit breaker with residual current protection (hereinafter referred to as "the circuit breaker") represents a new generation of devices developed by our company using internationally advanced design and manufacturing technologies. With a rated insulation voltage of 800V, it is suitable for AC 50Hz systems operating at a rated voltage of 400V and currents up to 630A. The circuit breaker is designed for infrequent circuit switching and motor starting applications. Beyond conventional overload, short-circuit, and undervoltage protection—which safeguard electrical lines and power equipment from damage—it also provides residual current protection. This additional functionality mitigates fire risks caused by persistent ground faults that may remain undetected by overcurrent protection alone.

The circuit breaker is categorized into two types based on rated ultimate short-circuit breaking capacity (Icu): Type M (enhanced breaking) and Type H (high breaking). Key features include compact dimensions, high breaking capacity, minimal arc flash distance, and vibration resistance.

Installation flexibility allows vertical (portrait) or horizontal (landscape) orientation. However, reverse power input is strictly prohibited—power must be connected to terminals 1, 3, 5, and load to terminals 2, 4, 6. The device also serves as an isolation switch.

Compliance Standards
The product adheres to the following international and national standards:

IEC 60947-1 & GB/T 14048.1 (General Rules)

IEC 60947-2 & GB 14048.2 (Low-Voltage Circuit Breakers, including Appendix B for residual current protection)

Circuit Breaker Classification
The circuit breakers are classified based on multiple parameters:

1. Pole Configuration
Divided into three-pole and four-pole variants. For four-pole models, the neutral pole (N-pole) is available in four configurations:

Type A: N-pole lacks overcurrent trip elements and remains permanently closed, independent of the other three poles' switching.

Type B: N-pole lacks overcurrent trip elements but switches synchronously with the other three poles (N-pole closes first and opens last).

Type C: N-pole integrates overcurrent trip elements and switches synchronously with the other three poles (N-pole closes first and opens last).

Type D: N-pole integrates overcurrent trip elements but remains permanently closed, independent of the other three poles' switching.

2. Rated Current (A) Ratings

ZYHM1L-100: 10 ratings — (10), 16, 20, 25, 32, 40, 50, 63, 80, 100A

ZYHM1L-225: 7 ratings — 100, 125, 140, 160, 180, 200, 225A

ZYHM1L-400: 5 ratings — 225, 250, 315, 350, 400A

ZYHM1L-630: 3 ratings — 400, 500, 630A

ZYHM1L-800: 3 ratings — 630, 700, 800A

3. Connection Methods
Available in three types: front-panel wiring, snap-on wiring, and plug-in configuration.

4. Overcurrent Trip Unit Types
Categorized into two variants:

Thermal-magnetic (compound) type

Magnetic (instantaneous) type

5. Accessory Configuration
Offered with or without accessories. Accessories are divided into internal and external categories:

Internal Accessories: Shunt trip device, undervoltage trip device, leakage alarm module, auxiliary contact, and alarm contact.

External Accessories: Rotary handle operating mechanism and motorized operating mechanism.