ER-CTB current transformer secondary overvoltage protector

◆Product Overview
In the power system, current transformers (CTs) are not allowed to open the secondary circuit during operation. Once the secondary winding is open or the primary winding current is abnormal, it will generate open circuit overvoltage of thousands or even tens of thousands of volts. In addition to damaging CTs and secondary equipment, it will also seriously threaten personal safety and even cause significant economic losses. The ER-CTB series current transformer secondary overvoltage protector produced by our company is designed for this situation. This product can effectively prevent power accidents caused by CT secondary overvoltage and is widely used in differential windings, measuring windings, overcurrent windings, busbar protection windings, backup windings, etc. on the secondary side.

◆Model Description

◆working principle
The secondary overvoltage protector of the ER-CTB current transformer is connected to the secondary winding of the CT through its own external terminal. When the CT is working normally, the input impedance of the protector is greater than 100M Ω, and the leakage current of each channel is ≤ 1 μ A, which does not affect the measurement and operation of the relay protection device.
The ER-CTB device can short-circuit the secondary winding within 10ms of overvoltage, thereby eliminating the overvoltage. At the same time, the corresponding fault winding indicator light on the panel lights up and outputs an alarm signal through the relay contact. The maintenance personnel check the corresponding secondary circuit according to the fault winding indicated by the indicator light. After troubleshooting, press the reset button, the fault light goes out, and the device returns to normal working state. If the indicator light remains on after pressing the reset button, it indicates that the fault has not been resolved and further investigation is required. Until the fault is resolved, reset it and it can be used again. The device has a lifespan of over 100000 actions, avoiding the inconvenience of replacing the protector after the action.

◆ Usage conditions
1. Indoor or semi outdoor use;
2. Environmental temperature: -10 ℃ to+85 ℃
3. Environmental humidity: ≤ 95% RH;
4. Altitude: ≤ 2000m;
5. Atmospheric pressure: 80-110Kpa;
6. The surrounding medium should be free of conductive dust, corrosive gases that may cause damage to metal or insulation, mold, etc.

◆Technical Specifications
1. Power supply: AC85N264V 50Hz or 110-360V DC
2. Normal leakage current: ≤ 1 μ A;
3. Conducting voltage: 150V ± 10% (default)