Standards

IEC/EN 60947‑1,
IEC/EN 60947‑4‑1,
IEC/EN 60947‑5‑1 (auxiliary switches)

3RT1 contactors in sizes S00 to S3 are suitable for use in any climate. They are finger-safe according to IEC 60529.

Connection method

The 3RT1 contactors are available with screw terminals (box terminals) or spring-type terminals.

The size S3 contactors have removable box terminals for the main conductor connections. This permits connection of busbars.

Contact reliability

If voltages ≤ 110 V and currents ≤ 100 mA are to be switched, the auxiliary contacts of the 3RT1 contactor or 3RH11 contactor relay should be used as they guarantee a high level of contact reliability.

These auxiliary contacts are suitable for solid-state circuits with currents ≥ 1 mA at a voltage of 17 V and higher.

Short-circuit protection

For short-circuit protection of the contactors without overload relay, see "Technical Specifications" of the relevant contactor.

For short-circuit protection of the contactors with overload relay, see the Configuration Manual "Configuring SIRIUS – Selection Data for Fuseless Load Feeders",
http://support.automation.siemens.com/WW/view/en/40625241.

To assemble fuseless motor feeders consisting of a motor starter protector and a contactor, selection guides are available as described in "3RA1 Load Feeders"; see "Load Feeders and Motor Starters" в†’ "for Use in the Control Cabinet".

Motor protection

3RB2 electronic overload relays can be fitted to the 3RT1 contactors for protection against overload. For overload relays, see "Protection devices".

Ratings of three-phase motors​

The quoted rating (in kW) refers to the output power on the motor shaft (according to the nameplate).

The power rating specifications of the contactors in kW are guide values for 4-pole standard motors at 50 Hz and specified voltage (e.g. 400 V AC). The actual starting and rated data of the motor to be switched must be considered when selecting the units.

Surge suppression

3RT1 contactors can be retrofitted with RC elements, varistors, diodes or diode assemblies (assembly of diode and Zener diode for short break times) for damping opening surges in the coil, see "Accessories and Spare Parts" в†’ “for SIRIUS 3RT1 Contactors and SIRIUS 3RH1 Contactor Relays" в†’ "Surge Suppressors".

Note:

The OFF-delay of the NO contact and the ON-delay of the NC contact are increased if the contactor coils are attenuated against voltage peaks (noise suppression diode 6 to 10 times; diode assembly 2 to 6 times, varistor +2 to 5 ms).

Auxiliary contact complement

Size S00 contactors have an auxiliary contact integrated in the basic unit. The basic units of sizes S0 to S3 contain only the main contacts when delivered. All basic units can be extended with auxiliary switch blocks.

For sizes S0 to S3, complete units with mounted auxiliary switch block 2 NO + 2 NC are available (terminal designation according to EN 50012); the auxiliary switch block can be removed.

Note:

Auxiliary contact complement according to SUVA: The size S00 to S3 contactors can also be supplied with permanently attached auxiliary switch block 2 NO + 2 NC (terminal markings according to EN 50012) according to SUVA.

Surge suppression

The surge suppressors are plugged onto the front of size S00 contactors. Space is provided for them next to a snap-on auxiliary switch block.

For size S0 to S3 contactors, varistors and RC elements can be snapped on either on the top or directly below the coil terminals. Diode assemblies are available in two different versions on account of their polarity. Depending on the application they can be connected either only at the bottom (assembly with motor starter protector) or only at the top (assembly with overload relay).

The plug-in direction of the diodes and diode assemblies is specified by coding.
Exceptions: 3RT1926-1T.00 and 3RT1936-1T.00,
in this case, the plug-in direction is marked with "+" and "-".

Article No. scheme

Note:

The Article No. scheme is presented here merely for information purposes and for better understanding of the logic behind the article numbers.