Power On and Off Operation Procedures

I. Precautions for Switching Operation

1. Before closing the switch, check that the high-voltage switch, low-voltage main switch, bus tie switch, each branch switch and their matching knife switches are in the off position. For closing operations after equipment maintenance, also check whether the grounding wires of each circuit have been removed and whether relevant equipment has been restored to its original state. Verify the wiring is completely correct before performing any switching operation.

2. Before closing, operate in accordance with the power supply circuit of the one-line diagram and the actual on-site power consumption conditions. Strictly comply with the relevant operating regulations formulated by the state during operation. In particular, complete the organizational and technical measures to ensure safety, and formulate on-site safety measures that conform to actual conditions before operation. Even if there is a minor doubt during the operation, it must be clarified before proceeding.

3. The operation shall be carried out by two personnel, one acting as supervisor and the other as operator. For complex operations, the call-and-repeat system shall be implemented in accordance with operational requirements.

II. Principles for Power On and Off Operation

1. Power-on principle: Follow the sequence of closing knife switches first, then load switches; closing high-voltage switches first, then low-voltage switches; closing knife switches on the power supply side first, then those on the load side; closing switches on the power supply side first, then those on the load side.

2. Power-off sequence: Reverse to the above operation principles.

III. Power On Process

(1) Standard Power On Process

1. Check the reset status of all equipment.

2. Remove the warning signs hung during power off.

3. Remove all grounding wires installed after power off and release the grounding knife switches.

4. Close the knife switch of the high-voltage power incoming line and check the voltage indication.

5. Close the vacuum switch of the high-voltage branch power incoming line to be powered on.

6. Close the high-voltage load switch to be powered on.

7. Check whether the phase and line voltages of the transformer are 380/220V.

8. Close the air switch on the low-voltage incoming line side.

9. Close the circuit breakers of each branch power incoming line as required.

10. Activate and adjust the reactive power compensation device to make COSθ = 0.9 (lagging), and switch it to automatic operation mode.

11. Check whether the power supply of each main and branch circuit is balanced, and whether each electrical component is overheated due to overload.

(2) Full Power Off Process

1. Turn the switch of the capacitor bank controller to the manual position and cut off each group one by one.

2. Open the circuit breaker and knife switch of the capacitor bank and perform discharge operation.

3. Cut off the power supply circuit breakers of each branch.

4. Cut off the main air switch of each low-voltage power incoming line and the power knife switch of the low-voltage main switch.

5. Cut off the high-voltage circuit breaker of each branch and the isolating switch of the high-voltage branch.

6. Cut off the main load switch and the main knife switch (isolating switch) of the high-voltage power incoming line.

7. Repeatedly test the electricity of the incoming and outgoing lines on the high and low voltage sides, busbars, transformers, capacitors, cables, and the incoming lines on both upper and lower sides of switches and knife switches, and conduct sufficient discharge. During the electricity test, test the electroscope repeatedly to confirm its good condition.

8. Install grounding wires on each side where power may be supplied (connect the grounding end first, then the conductor end) and close the grounding knife switch of the high-voltage branch.

9. Immediately lock each machine room and switch cabinet where power may be supplied, and hang the sign of "Line in operation, No closing".