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  • New item   Capacitor switching contactor | 12.5–80 kvar | with pre-charge resistors | for capacitor banks | Lifasa
    New item   Capacitor switching contactor | 12.5–80 kvar | with pre-charge resistors | for capacitor banks | Lifasa 1
    New item   Capacitor switching contactor | 12.5–80 kvar | with pre-charge resistors | for capacitor banks | Lifasa 2
    New item   Capacitor switching contactor | 12.5–80 kvar | with pre-charge resistors | for capacitor banks | Lifasa 3
    New item   Capacitor switching contactor | 12.5–80 kvar | with pre-charge resistors | for capacitor banks | Lifasa 4
    New item   Capacitor switching contactor | 12.5–80 kvar | with pre-charge resistors | for capacitor banks | Lifasa 5
    New item   Capacitor switching contactor | 12.5–80 kvar | with pre-charge resistors | for capacitor banks | Lifasa 6

    Capacitor switching contactor | 12.5–80 kvar | with pre-charge resistors | for capacitor banks | Lifasa

    Code: SKU#158377520622052751
    Barcode:
    Price 25.05 € VAT incl.
    ( 20.70 € VAT excl. )

    Lifasa capacitor switching contactors for capacitor banks, 12.5 / 25 / 30 / 50 / 60 / 80 kvar. The early-make block with resistors limits the inrush current and disconnects automatically after switch-on. Controlled from the cos φ controller relay, mounted on DIN rail or with screws.

  • Product description

    Capacitor switching contactor | 12.5–80 kvar | with pre-charge resistors | for capacitor banks | Lifasa

    Lifasa capacitor switching contactors are designed for three-phase capacitor steps in automatic power factor correction cabinets. The contactors feature an early-make block with resistors that limits the capacitor inrush current.

    Key idea:
    When a capacitor is switched on, the inrush current can be several times the rated current. A standard motor contactor quickly burns out under these conditions, whereas the resistors of a capacitor contactor first "pre-charge" the capacitor, and only then do the main contacts close.
    Rating
    12.5 / 25 / 30 / 50 / 60 / 80 kvar (by variant)
    Purpose
    switching of capacitor steps
    Inrush protection
    early-make block with pre-charge resistors
    Control
    from the cos φ controller relay

    Operating principle

    The contactor is installed in the capacitor bank between the capacitor step fuses and the capacitor. Its coil is controlled by a relay output of the automatic cos φ controller.

    On receiving a command, the early-make contacts close first: the capacitor is connected through the resistors, which reduces the inrush current. Shortly afterwards the main contacts close, and the auxiliary contacts with resistors are automatically disconnected.

    This protects the main contacts, the capacitor and the network from sudden current surges, and the cabinet steps last longer.

    Why use a capacitor contactor?
    It is designed specifically for switching capacitors: it limits the inrush current, so the contacts do not burn or weld, and the capacitors are not subjected to surge loads every time they switch on.

    Technical specifications

    Product type Capacitor switching contactor (three-phase)
    Manufacturer Lifasa
    Step rating 12.5 / 25 / 30 / 50 / 60 / 80 kvar – selectable by variant
    Network voltage (by variant) 440 V AC
    Early-make block auxiliary contacts with resistors in each phase, disconnected automatically
    Coil voltage Lifasa standard – 230 V AC, 50/60 Hz (please confirm when ordering)
    Auxiliary contacts depend on the rating (NC / NO), confirm according to the model
    Mounting on DIN rail or with screws
    Standard IEC 60947

    Key functions

    • Inrush current limiting – resistors reduce the capacitor switch-on surge
    • Automatic resistor disconnection – after switch-on the resistors are out of circuit and do not heat up
    • Designed for capacitors – longer contact life than with a standard contactor
    • Control from the controller – the coil is connected to the cos φ controller relay
    • Auxiliary contacts – enable step status signalling or interlocking

    Where is it used?

    • Automatic power factor correction cabinets
    • Replacement of burnt-out or worn step contactors
    • Assembly of new compensation steps
    • Individual compensation steps
    • Distribution boards in manufacturing plants, warehouses and commercial buildings

    Use by need

    For capacitor bank builders.
    The contactor rating is selected according to the step kvar, making cabinet assembly simple and clear.
    For maintenance electricians.
    A burnt-out contactor can be replaced with a capacitor contactor of the same rating, without replacing the whole cabinet.
    For the site energy manager.
    The right contactor protects expensive capacitors and reduces the number of capacitor bank failures.

    Practical application

    If the contactor of a 25 kvar step in a capacitor bank is burnt but the capacitor is intact, replace it with a capacitor contactor of the same rating (25 kvar). Before doing so, check the coil voltage and whether the controller is switching the steps too often – a delay that is too short will quickly burn out the new contactor as well.

    Pros

    • Designed for capacitor switching
    • Pre-charge resistors limit the inrush current
    • Resistors disconnect automatically after switch-on
    • Ratings from 12.5 to 80 kvar
    • Mounting on DIN rail or with screws

    Cons / limitations

    • Not suitable for motor control – standard contactors are used for that
    • Not suitable for fast (dynamic) compensation – thyristor switches are required for that
    • Coil voltage and auxiliary contacts must be confirmed according to the model

    Safety and installation notes

    • Before any work, disconnect the cabinet and make sure the capacitors are discharged
    • The contactor rating must match the kvar of the step capacitor
    • Protect the step with the fuses specified by the manufacturer
    • Set a sufficient reconnection time in the controller so that the capacitor has time to discharge
    • Check that the coil voltage matches the control circuit voltage

    Quick selection guide

    12.5–80 kvar
    440 V AC network
    pre-charge resistors
    DIN rail / screws
    Suitable when you need:
    • switching capacitor steps in an automatic cabinet
    • replacing a burnt-out step contactor
    • assembling a new capacitor bank
    Check before use:
    • the step capacitor rating in kvar
    • the network voltage
    • the coil voltage
    • the need for auxiliary contacts
    Important reminder: A capacitor contactor does not replace detuning reactors – if there are high harmonics on site, the cabinet needs steps with detuning reactors.

    FAQ

    Why can't a standard contactor be used?
    The capacitor inrush current quickly burns the contacts of a standard contactor.
    How do I select a contactor?
    According to the kvar rating of the step capacitor and the network voltage.
    Do the resistors heat up continuously?
    No, they operate only during switch-on and are then disconnected automatically.
    What is the coil voltage?
    The Lifasa standard coil is 230 V AC, 50/60 Hz; please confirm when ordering.
    Is it suitable for rapidly changing loads?
    No, thyristor switches are used for very fast compensation.
    Can it be mounted on a DIN rail?
    Yes, the contactor is mounted on a DIN rail or with screws.
    Disclaimer. This description is based on manufacturer data and is provided for information only. Final selection, connection and commissioning must be carried out by a qualified electrician in accordance with the site design and applicable requirements. UAB „Elektrotechnikos sprendimai“ accepts no liability for selection or connection carried out solely on the basis of this description.

    Lifasa capacitor contactors 12.5–80 kvar with pre-charge resistors

    Lifasa capacitor switching contactors with pre-charge resistors limit the capacitor inrush current and extend the life of capacitor bank steps. Ratings 12.5 / 25 / 30 / 50 / 60 / 80 kvar, mounting on DIN rail or with screws.

    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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