Residual current circuit breaker with overcurrent protection KZS-4M 3P+N A 25/0.03 002174906

### Protection and safety in your electrical installation

The KZS-4M residual current circuit breaker with overcurrent protection is a comprehensive solution ensuring the protection of people and devices in electrical circuits. Its primary function is to protect against electric shock, both in the case of direct and indirect contact. Additionally, it effectively protects against the effects of short circuits and overloads, minimizing the risk of fire caused by insulation damage. This device combines the functions of an overcurrent and residual current circuit breaker, simplifying the installation and increasing its reliability.

Universal application and solid construction

The KZS-4M circuit breaker is designed for use in TN-S, TN-C-S, TT and IT networks where the neutral and earth conductors are separated. It has 4 poles (3P+N), making it ideal for protecting three-phase circuits with a neutral conductor. The device width – 4 modules – allows for easy mounting in standard distribution boards. The materials used and the construction guarantee high durability and reliability even in harsh working conditions.

Key features and benefits

• Multifunctionality: combination of overcurrent circuit breaker function (B characteristic) and residual current circuit breaker (type A) in one device. This means saving space in the distribution board and simplifying the installation.
• High sensitivity: rated residual current of 0.03A ensures a quick response to leakage currents, minimizing the risk of electric shock.
• Short-circuit capacity: 6kA – guarantees effective disconnection of the circuit in the event of a short circuit, protecting the remaining elements of the installation.
• Suitable for different conductor cross-sections: possibility of connecting stranded conductors with a cross-section from 1 to 35 mm² and solid conductors from 1 to 25 mm², provides flexibility during installation.
• Safety of use: the "Test" button allows for regular checking of the residual current circuit breaker functionality, and the contact position indicator facilitates identification of the device status (ON/OFF).
• Touch protection: protected terminals minimize the risk of accidental electric shock during maintenance or repair of the installation.
• Expandability: compatible with auxiliary contacts PS KZS-2M/4M, allowing integration with monitoring and control systems.

Technical parameters in practice

The KZS-4M circuit breaker is characterized by a rated voltage of 400V and a frequency of 50/60Hz, making it compatible with most standard electrical installations. Energy limitation class 3 provides adequate protection against the effects of overvoltages. The cross-section of the connected conductor can be adapted to the needs of a specific application – from 1 mm² to as much as 35 mm² for stranded conductors. Characteristic B provides fast tripping in the event of overloads, but allows for short-term current surges, typical for starting motors or other devices with high power consumption.