Besides standard approval in compliance with IEC 60974‑4‑1, the contactors with an extended operating range are also approved in compliance with IEC 60077‑2, thus fulfilling the requirement for use in railway applications.

Thus, their suitability for increased requirements such as an

• extended temperature range in comparison with the regular standard IEC 60497‑4‑1 or
• extended operating range of the solenoid coils or also
• increased resistance to mechanical oscillations and vibrations is warranted. The design of the terminals in the spring-type connection system also contributes toward vibration resistance.

3RT20 contactors with conventional coil

Control and auxiliary circuits

These contactors have an extended operating range from 0.7 to 1.25 x U_s; on size S00 the coils are fitted with suppressor diodes, on size S0 with varistors. An additional series resistor is not required.

Note:

An additional auxiliary switch block cannot be mounted.

Side-by-side mounting

A clearance of 10 mm is required for side-by-side mounting at ambient temperatures > 60 °C в‰¤ 70 °C.

3RT201 contactors with series resistor

Control and auxiliary circuits

The solenoid coils of these contactors have an extended operating range from 0.7 to 1.25 x U_s and are fitted as standard with a surge suppressor (suppressor diode or varistor as preferred).

The DC solenoid systems of the contactors are modified (to holding excitation) by means of a series resistor.

3RT201 to 3RT204 as well as 3RT105 to 3RT107 contactors with solid-state operating mechanism, extended operating range

Control and auxiliary circuits

The solenoid coils and/or operating mechanisms of these contactors have an extended operating range from 0.7 to 1.25 x U_s and are fitted with varistors as standard to provide protection against overvoltage.

The contactors are energized via upstream control electronics which ensure the coil operating range of 0.7 to 1.25 x U_s at an ambient temperature of 70 °C. They are supplied as complete units with integrated coil electronics. A varistor is integrated for damping opening surges in the coil.

3RT105 to 3RT107 contactors come with an additional control connection (PLC‑IN) for direct connection to controllers with a rated DC operating range of 24 V to 100 V as well as a selector switch for the mode of operation. The contactors can optionally be controlled either directly via A1/A2 or via the additional PLC‑IN connection.

The option of mounting auxiliary switches is the same as that for equivalent standard contactors for switching motors in the matching size, see the overview diagrams of the 3RT contactors, "Power Contactors for Switching Motors".

Side-by-side mounting

With these contactor versions in sizes S00 and S0, side-by-side mounting is permitted at ambient temperatures up to 70°C.