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  • New item   Modular residual current device | 4P | 20A | 0.03A | type AC | DIN | ECO FPR-AC | Promfactor Baltic | FPR4020030AC
    New item   Modular residual current device | 4P | 20A | 0.03A | type AC | DIN | ECO FPR-AC | Promfactor Baltic | FPR4020030AC 1

    Modular residual current device | 4P | 20A | 0.03A | type AC | DIN | ECO FPR-AC | Promfactor Baltic | FPR4020030AC

    Code: FPR4020030AC
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    Price 19.75 € VAT incl.
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  • Product description

    Modular residual current device | 4P | 20A | 0.03A | type AC | DIN | ECO FPR-AC | Promfactor Baltic | FPR4020030AC

    FPR4020030AC – Promfactor Baltic FPR-AC series modular residual current device (RCCB): 4P, rated current 20 A, residual current 30 mA, type AC, electromechanical. Designed for three-phase ~400 V circuits (3 phases + neutral); used for additional protection of people against electric shock – socket, bathroom, outdoor and other circuits where 30 mA is required. The device does not protect against overload or short circuit – a circuit breaker is installed upstream or downstream for that.

    Key idea:
    FPR4020030AC continuously compares the current flowing into and out of the circuit: when the difference reaches 30 mA, the device disconnects all 4 poles. Type AC residual current protection responds to sinusoidal AC leakage currents – suitable for heating, lighting and ordinary socket circuits without high-power electronics. The rated current of 20 A is the operating current the device can carry through its contacts.
    Rated current
    20 A
    Residual current
    30 mA (0.03 A)
    Type
    AC, electromechanical
    Poles / voltage
    4P (3P+N) / ~400 V

    Operating principle

    The device is mounted in the panel on a 35 mm DIN rail. All live conductors of the circuit – three phases and neutral – pass through its measuring transformer. The protective PE conductor is not routed through the device.

    While the current balance is intact, the magnetic fluxes in the transformer core cancel each other out. When current leaks to earth through a person or damaged insulation, a signal is induced in the secondary winding, and at 30 mA the electromechanical release trips the device within ≤0.1 s. Electromechanical operation does not depend on the supply voltage.

    Result – a three-phase circuit or group block up to 20 A is protected against residual currents, and the "T" button allows periodic function testing. The device works together with circuit breakers that protect the cables against overload and short circuit.

    Why choose FPR4020030AC?
    One 4P device can protect several circuits with separate circuit breakers, so the panel is more economical than with an RCBO for each circuit; the FPR-AC series includes 2P and 4P devices with 30, 100 and 300 mA sensitivity.

    Technical specifications

    Product typeModular residual current device (RCCB)
    Manufacturer / codePromfactor Baltic / FPR4020030AC
    SeriesFPR-AC (2P, 4P; 30 / 100 / 300 mA)
    Number of poles4P (3P+N)
    Rated current (In)20 A
    Rated residual current (IΔn)30 mA (0.03 A)
    Residual current typeAC
    Release typeElectromechanical
    Rated voltage (Un)~230/400 V
    Frequency50/60 Hz
    Insulation voltage (Ui)500 V
    Impulse withstand voltage (Uimp)4000 V
    Short-circuit current (stated by manufacturer as Icu)10 000 A
    Instantaneous tripping time≤0.1 s
    Electrical / mechanical endurance4000 / 20 000 cycles
    Terminalscable up to 25 mm²; tightening torque 3.5 Nm
    Mounting35 mm DIN rail
    Degree of protectionIP20
    Operating temperature-25…+55 °C
    Storage temperature-25…+70 °C

    Main functions

    • Residual current protection 30 mA – additional protection of people against electric shock in case of direct or indirect contact.
    • Type AC – detects sinusoidal AC leakage currents – suitable for circuits without high-power electronics.
    • Electromechanical release – operation does not depend on supply voltage – the device trips even if the neutral is lost or the voltage drops.
    • All 4 poles disconnected – in case of leakage, all phase and neutral conductors are disconnected.
    • "T" button – allows periodic testing of the tripping mechanism.
    • Modular housing – mounts on a 35 mm DIN rail next to circuit breakers.

    Where is it used?

    • Three-phase incoming panels of houses and farmsteads
    • Workshops and garages with three-phase equipment
    • Distribution panels of commercial premises
    • Farm buildings
    • Construction site panels
    • Heat pump and electric heating circuits
    • Group blocks in industrial premises

    Use by need

    For the installing electrician.
    One 20 A 30 mA device protects a block of three-phase circuits without a separate RCBO for each.
    For the house or farmstead owner.
    The three-phase supply, workshop or heating equipment gets residual current protection in line with electrical safety requirements.
    For the designer.
    The FPR-AC series has 4P devices with 30, 100 and 300 mA – convenient for building protection stages.

    Practical application

    If in a three-phase panel a block of circuits is supplied through circuit breakers and the total load does not exceed 20 A, then FPR4020030AC is installed upstream of these breakers: in case of leakage it disconnects the whole block, while overload and short circuit are still handled by the circuit breakers.

    Advantages

    • 30 mA residual current protection, type AC
    • Electromechanical operation – independent of voltage
    • Disconnects all 4 poles
    • "T" button for periodic testing
    • IP20, operating temperature -25…+55 °C
    • One device can protect several circuits

    Disadvantages / limitations

    • Does not protect against overload and short circuit – a circuit breaker is required
    • Type AC is not suitable for circuits with frequency converters, inverters or EV charging – choose type A, F or B
    • In case of leakage, all circuits protected by the device are disconnected
    • Many circuits with background leakage on one 30 mA device may cause nuisance tripping

    Safety and installation notes

    • Installation by a qualified electrician after disconnecting the supply and verifying absence of voltage
    • Route all live conductors through the device; do not route the PE conductor through it
    • Do not interconnect the neutral conductors of different residual current devices
    • Protect the device with a circuit breaker not exceeding 20 A
    • After installation, check operation with the "T" button and an RCD tester

    Quick selection guide

    4P
    20 A
    30 mA
    type AC
    ≤0.1 s
    DIN 35 mm
    Suitable when you need:
    • residual current protection of a three-phase group block
    • loads up to 20 A
    • additional protection of people
    Check before use:
    • whether there is a circuit breaker ≤ 20 A upstream
    • whether type AC suits the connected equipment
    • that neutrals are not shared with other circuits
    • that the panel has 4 free modules
    Important reminder: A residual current device does not replace protective earthing, circuit breakers or periodic inspection of the electrical installation.

    FAQ

    Does FPR4020030AC protect against short circuit?
    No – a circuit breaker is installed upstream or downstream for that.
    What do 20 A and 30 mA mean?
    20 A is the rated operating current through the contacts, 30 mA is the residual current at which the device disconnects the circuit.
    Is it suitable for circuits with an inverter or frequency converter?
    No – for such circuits choose type A, F or B according to the equipment manufacturer.
    How often should the "T" button be pressed?
    Periodically, for example every few months, and after any work in the panel.
    How many modules does it take?
    The four-pole device takes 4 modules on the DIN rail.
    Can the PE conductor be routed through the device?
    No – only phase and neutral conductors pass through the device.

    Modular residual current device | 4P | 20A | 0.03A | type AC | DIN | ECO FPR-AC | Promfactor Baltic | FPR4020030AC

    Promfactor Baltic FPR4020030AC – modular residual current device FPR-AC 4P 20 A 30 mA type AC, electromechanical, DIN rail – protection of three-phase circuits against residual currents and electric shock.

    Published: 2026-11-07 · Data verified against the manufacturer's datasheet: 2026-11-06

    Illustrative image may have been created using AI. The appearance of the product may differ slightly from the image shown. Please refer to the technical specification.

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