Standards

IEC/EN 60947‑1, IEC/EN 60947‑4‑1, IEC/EN 60947‑5‑1, IEC/EN 60831‑1, IEC/EN 61921

The 3RT26 contactors are suitable for use in any climate. They are finger-safe according to IEC 60529.

Function

The 3RT26 contactors for capacitive loads (AC‑6b) are special versions of the 3RT20 contactors in sizes S00 to S3 that are configured for switching banks of capacitors.

They are designed to convey the inrush current in such applications, and are weld-resistant in compliance with the technical specifications.

3RT26 contactors are suitable for capacitors with and without reactor protection. Besides switching power capacitors in reactive-current compensation systems, they are also used to switch converters.

In the case of 3RT26 contactors, the precharging resistors are an integral component of the contactor. The pre-charging resistors are activated via leading auxiliary contacts before the main contacts close. During switching, they are decoupled again after attenuation of the peak current. Attenuation of the inrush current peaks also reduces interfering harmonics in the supply.

Notes:

Only switching onto discharged capacitors is permitted with 3RT26 contactors.

Manual operation for function tests is not permitted. The series resistors must not be removed.

Auxiliary switches

The variance of unassigned auxiliary switches has been increased; see the ordering data for available versions. Versions differing from this can be requested.

In sizes S00 and S0, the auxiliary switch block snapped onto the capacitor contactor contains the three leading NO contactors as well as one freely available auxiliary contact. In addition, one (S00) or two (S0) other freely available auxiliary contacts are available in the basic device.

The fitting of auxiliary switches for 3RT26 contactors in sizes S00 and S0 of the respective version is not expandable. For sizes S2 and S3, freely available auxiliary switches are implemented by means of lateral auxiliary switch blocks. Further auxiliary switch blocks can be mounted laterally in accordance with the 3RT20 contactors.

Devices with 2 NC are now consistently available in all power quantities.