Standards

IEC/EN 60947‑4‑1, IEC/EN 60077‑2

The contactors are finger-safe according to IEC 60529 (exception: S3 series resistor). The auxiliary conductor and coil terminals are all spring-type terminals.

Ambient temperature

The permissible ambient temperature for operation of the contactors (across the full coil operating range) is -40 to +70 °C.

Power range

3RT contactors are available in all sizes from S00 to S12 up to 250 kW or 500 A (AC‑3 at 400 V).

Operating range of contactor operating mechanism

Sizes S00 to S3

The solenoid coils of the 3RT2 contactors have an extended operating range from max. 0.7 to 1.25 x U_s and are fitted as standard with surge suppressors. The opening delay is consequently 2 to 5 ms longer than for standard contactors.

Sizes S6 to S12

The operating mechanism for the 3RT10 contactors features solid-state control of the contactor coil. Overvoltage damping of the operating mechanism coil is already integrated in the electronics. The operating mechanisms are powered via a supply voltage with an operating range of 0.7 to 1.25 x U_s, optionally also controlled depending on the chosen mode of operation. Alternatively, control is via the separate 24 to 110 V DC control signal input.

Three rated voltage ranges are available as direct voltage (DC):

• 24 V DC
• 72 V DC
• 110 V DC