Residual current circuit breaker Type B - NFI4BK

Residual current circuit breaker Type B - NFI4BK

The ISKRA NFIB circuit breaker is a type B circuit breaker (RCCB), which prevents damage to the property and health. It shuts down the circuit in the same way as a type A RCD, and it also monitors residual currents in the DC component that may result from the presence of rectifier circuits and high-frequency AC as a residual current.

Product options

  • £175,12 incl. VAT


    £199 incl. VAT Discount 12%

  • £189,20 incl. VAT


    £215 incl. VAT Discount 12%

  • £207,68 incl. VAT


    £236 incl. VAT Discount 12%

£175,12 incl. VAT


£199 incl. VAT Discount 12%

Producer: Iskra

Product rating: 4.62/5 (13x)

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The type B circuit breaker is intended for use in applications with frequency converters, in medical devices, UPS, mobile installations, elevators and more. Type B circuit breakers are not intended for use in DC systems and networks with operating frequencies other than 50 or 60 Hz. Conditions for frequencies up to 1 kHz are defined for cuircuit breakers of type B.

The detection, evaluation and interruption functions of residual currents of type A do not depend on the voltage in the grid, to evaluate the smooth DC component, a residual current supply voltage greater than 50 V is required. It can be used on any two poles. When designing and installing electrical installations, electrical loads can generate DC residual current and, in the event of a fault, must be assigned a separate electrical circuit.

Technical Specifications

  • Residual current frequency: 1kHz
  • NFIBK: short-term delay delay
  • The capacity of overvoltage current with a current profile of 8/20 µs is 3 kA
  • Number of poles: 2P, 4P
  • Rated AC voltage (V): 230 / 400V
  • Rated current (A): 25, 40, 63, 80A
  • Rated frequency (Hz): 50Hz
  • Rated residual operating current (A): 30 mA
  • Tightening torque (Nm): 2Nm
  • Working temperature: -20 ° to 50 ° C
  • Dimensions: 86 x 70 x 58 mm
  • Weight: 350g

Security and certificates

The RCD is designed for mounting on a 35 mm wide mounting rail in accordance with EN 60715. The RCD is IP20 certified for protection against moisture and dust and IP40 after installation in a control cabinet.

The circuit breaker is provided with a standard 24-month warranty.

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