1. Product description:
SCPI series protection unit is a special protection unit designed for high-voltage shunt capacitor reactive power compensation device. It is developed and developed based on microprocessor technology. Through continuous real-time sampling of various electrical parameters related to the operation of the capacitor, the operation of the capacitor is judged through logic analysis Status: When an abnormality is detected, the capacitor will be cut off in time or an alarm will be given to the upper control system to ensure the safe operation of the capacitor.

2. Protect the project
◆Undervoltage protection: When the bus voltage is lower than the undervoltage setting value and reaches the set delay time;
◆Overvoltage protection: When the bus voltage is higher than the overvoltage set value and reaches the set delay time;
◆Harmonic protection: When the total harmonic distortion rate of the bus voltage exceeds the set value of harmonic protection and reaches the set delay time;
◆Overcurrent protection: When the current of the capacitor bank exceeds the overcurrent set value and reaches the set delay time;
◆Quick-break protection: When the current of the capacitor bank exceeds the quick-break setting value and reaches the set delay time (two-stage overcurrent);
◆Open delta voltage protection: When the open delta zero sequence voltage value of single star connection exceeds the set value and reaches the set delay time;
◆Central point unbalanced current protection: when the unbalanced current at the central point of the double star connection exceeds the set value and reaches the set delay time;
◆Phase differential voltage protection: provide three groups (three-phase) unbalanced voltage protection. When the differential voltage of any phase exceeds the set value and reaches the set delay time, the protection will act.
◆Bridge differential current protection: provide three groups (three-phase) unbalanced current protection. When the bridge difference current of any phase exceeds the set value and reaches the set delay time, the protection will act.
When the protection occurs, the outlet relay will act to cut off the capacitor or notify the upper control system. For details, please refer to the following protection chapter.

3. Model definition

4. Installation size:
SCPI is a cabinet surface-mounted type, and its appearance is shown in Figure 1. Dimensions: 160mm wide, 80mm high, and 95.5mm deep.
When installing, make a hole on the installation plane in advance, as shown in Figure 2.

Figure 2 Hole size

5. Wiring terminal
The wiring terminal on the back of the protection unit is shown in the figure:
1. SCPI-AK terminal

SCPI-AK outlet arrangement