Current Transformers (CTs) Function

Current transformers (CTs) are used within the CCR to monitor electrical current. They provide feedback to the control system to ensure proper regulation and monitoring of output current.

Output Current Transformer

The primary CT monitors the CCR output current. It measures actual series circuit current. It provides feedback to the control circuitry. It allows the system to maintain the programmed current level. It supports fault detection and logging. The output CT is a critical part of the current regulation loop. Without accurate output current feedback, the CCR cannot maintain proper constant current operation.

Role in Regulation

The CCR maintains constant current by comparing the programmed target current and the actual measured output current. The output CT provides the measured value. If a deviation occurs, the control system adjusts SSR conduction timing. Output voltage is modified accordingly. Current stabilizes at the selected brightness step.

Optional Input Current Transformer

Some configurations include an input CT. The input CT is used to monitor input current. It provides additional diagnostic information. It supports monitoring functions in L-829 models. Input current monitoring does not control output current but provides useful system data.

Fault Detection

CT feedback supports detection of output current out of tolerance, abnormal operating conditions, and fault scenarios. If measured current does not match expected values, the DCMU may log warnings or faults.

Airport Lighting Company | Type L-828, Type L-829 Ferroresonant Constant Current Regulator