Transformer-protective circuit-breakers and current limiters [t-head1]

PKZM0-T [t-head3]

The transformer-protective circuit-breaker is designed for protecting transformer primaries. The short-circuit releases in the types from 0.16 A to 25 A are permanently set to 20 × I_u. The response ranges of the short-circuit releases are higher here than with motor-protective circuit-breakers in order to cope with the even higher inrush currents of idling transformers without tripping. The overload release in the PKZM0-T is set to the rated current of the transformer primary. All the PKZM0 system accessories can be combined with the PKZM0-T.

PKZM0-...-C [t-head3]

The PKZM0 features a version with springloaded terminals. A version with springloaded terminals on both sides, and a combined version which features springloaded terminals on the outgoer side only can be chosen. The conductors can be connected here without ferrules. The connections are maintenance-free.

CL-PKZ0 [t-head3]

The current limiter module CL-PKZ0 is a short-circuit protective device specially developed for the PKZM0 and PKZM4 for non-intrinsically-safe areas. The CL module has the same base area and uses the same terminations as the PKZM0. When they are mounted on a top-hat rail alongside one another, it is possible to connect them using B3...-PKZ0 three-phase commoning links. The switching capacity of the series connected PKZM0 or PKZM4 + CL is 100 kA at 400 V. In the event of a short-circuit, the contacts of the motor-protective circuit-breaker and CL will open. While the current limiter returns for the closed rest position, the motor protective-circuit breaker trips via the instantaneous release and produces a permanent isolating gap. The system is ready to operate again, once any defect has been rectified. The current limiter can conduct an uninterrupted current of 63 A. The module may be used for individual or group protection. Any feed direction may be used.

Individual and group protection with CL-PKZ0 [t-head3]

Examples: