Secondary Overvoltage Protector for Current Transformer

Current transformers (CT) are widely used in primary measurement and control in power systems. Under normal operation, the secondary side of the transformer is in a near-short-circuit state, and the output voltage is very low. During operation, if the secondary winding is open-circuited, or if an abnormal current (such as lightning current, resonant overcurrent, capacitor charging current, inductor starting current, etc.) flows through the primary winding, overvoltages of several thousand volts or even tens of thousands of volts will be generated on the secondary side. This not only damages the insulation of the secondary system but can also cause the transformer to overexcite and burn out, and even endanger the lives of personnel. Using a CT secondary overvoltage protector can effectively prevent accidents caused by open circuits in the secondary side of the current transformer.

Intelligent processing to prevent human error

Strong anti-interference capability, preventing malfunction due to interference

Fast protection action

DIN rail mounting

Overvoltage Clamping: Real-time monitoring of the CT secondary circuit voltage. When the voltage rises abnormally due to an open circuit and exceeds a set threshold, the protector immediately activates, limiting the voltage to a safe value (typically below 150V).

Automatic Reset: Once the open circuit fault is cleared and the secondary circuit voltage returns to normal, the protector automatically cuts off the conduction circuit and resumes normal monitoring without manual intervention.

Status Indication: The device is typically equipped with LED indicator lights or mechanical labels that clearly display the protector's operating status (normal/activated), facilitating rapid diagnosis by maintenance personnel.

Ensuring Measurement Accuracy: During normal operation, the protector presents a high impedance state, having virtually no impact on the measurement accuracy of the CT secondary circuit or the relay protection operation.

Power Generation Systems:Step-up substations and plant auxiliary power systems for thermal, hydroelectric, wind, and photovoltaic power plants.

Transmission and Distribution Systems:Protection and metering cabinets in substations, switching stations, and distribution rooms at all levels.

Industrial Sector: Power distribution systems in steel, chemical, petroleum, mining, and rail transportation industries. Specific installation location: It can be directly installed on the output terminal box of the CT secondary winding, the terminal block of the switch cabinet, or the relay protection panel.

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