The Z-FT First Trip Monitoring module (AC Current Clamp) is designed for on-line circuit breaker testing, allowing the analysis of the breaker’s first trip operation while the system remains energized. It provides accurate measurement of breaker opening behavior without requiring an outage or disconnection of the circuit.
The system is based on a current transducer installed on the breaker circuit, enabling the monitoring of current evolution during the first trip event. This allows users to determine the exact moment of contact opening and evaluate the interruption process under real operating conditions.

During testing, the Z-FT module is connected to the analog inputs of the Zensol CBA-32P/CBV-19/32 or CB instruments. The recorded signals are processed and displayed in CBAWin software, where the first trip event can be analyzed in relation to time, current decay, and breaker control actions.

The Z-FT is used to verify the correct behavior of circuit breakers during their first operation under live conditions, supporting commissioning, diagnostics, and maintenance activities in high-voltage substations. It also allows engineers to confirm whether current interruption occurs as expected during the opening sequence.
Multiple transducers can be used simultaneously to monitor different phases of a three-phase system, providing a complete view of breaker performance across all poles.

By enabling safe and accurate on-line measurement of first trip behavior, the Z-FT module provides essential diagnostic information for evaluating circuit breaker condition and control performance in real operating environments.