Five Prohibited Dangerous Operations for High-Voltage Switchgear

To ensure the safe and stable operation of Huihai high-voltage switchgear and prevent electric shock, equipment damage, and power grid accidents, and in accordance with strict adherence to power safety operation regulations, and considering the structural design and operating characteristics of Huihai switchgear, the following five dangerous operations are explicitly prohibited. All operators must strictly abide by these regulations and are strictly forbidden from violating them, upholding the safety red line and eliminating all safety hazards caused by unauthorized operations.

1. Strictly Prohibited to Incorrectly Open or Close Circuit Breakers

1.1. Meaning of Prohibition

• Without formal operating instructions from the dispatcher/duty supervisor, without verifying the equipment number, and without confirming the operating status, it is strictly prohibited to arbitrarily, blindly, or forcibly open or close high-voltage circuit breakers.

1.2. Prohibited Behaviors

• Operating circuit breakers without a permit or dispatching order.
• Misreading cabinet numbers or bays, resulting in the accidental operation of other operating circuit breakers.
• Blindly opening or closing circuit breakers without confirming their status during equipment maintenance or testing.
• Forcibly unlocking circuit breakers locally, illegally short-circuiting interlocks, or improperly opening or closing circuit breakers.

1.3. Major Safety Hazards

• Misoperation of operating circuit breakers: Causes unexplained power outages and load interruptions, affecting production power supply.
• Misoperation of standby/maintenance circuit breakers: Easily leads to faulty power supply, phase-to-phase short circuits, equipment burnout, and arc explosions.
• Easily causes grid fluctuations, protection malfunctions, expands the scope of accidents, and endangers personal and equipment safety.

1.4. Standard Operating Requirements

• Strictly adhere to the "two-ticket, three-system" approach: operate only with an operating ticket and under instruction.
• Double-check equipment name, number, and interval before operation.
• One person must operate and one person must supervise, unauthorized operation by a single person is strictly prohibited.
• Unauthorized removal of the anti-misoperation interlocking device for forced operation is strictly prohibited.

2. Prohibition of Opening or Closing Disconnect Switches (Turnouts) Under Load

2.1. Explanation of Prohibitions

• Disconnect switches do not have arc-extinguishing functions. When the circuit breaker is not open and still under load, it is strictly prohibited to push or pull the switchgear turnout or to open or close the disconnect switch.

2.2. Prohibited Violations

• Forcibly pulling out the switchgear turnout while the circuit breaker is closed and energized.
• Directly opening or closing the disconnect switch while the equipment is under load.
• Operating the disconnect switch directly without first disconnecting the circuit breaker to save time.
• Unlocking the interlocking device without authorization and forcibly opening or closing the disconnect switch under load.

2.3. Safety Hazards

• Instantaneous generation of a strong high-voltage electric arc, causing phase-to-phase short circuits and switchgear explosions.
• Arc burns operators, easily causing serious injury or electric shock death.
• Damage to high-voltage equipment, causing large-scale power outages and escalating power accidents.

2.4. Standard Operating Principles

• Open the circuit breaker first, then pull the disconnect switch; close the disconnect switch first, then close the circuit breaker.
• Strictly follow: When de-energizing, first disconnect the switch, then pull the disconnect switch; when energizing, first close the disconnect switch, then close the switch.

3. It is strictly forbidden to hang (or close) grounding wires (grounding switches) while the equipment is energized.

3.1. Explanation of the prohibition:

• When high-voltage equipment is not de-energized, not tested for voltage, and is still in an energized state, it is strictly forbidden to hang temporary grounding wires or forcibly close the grounding switches inside the cabinet.

3.2. Prohibited Violations

• Connecting the grounding wire while the power is on without completing the power outage procedure.
• Blindly closing the grounding switch without verifying the voltage.
• Taking chances and skipping the power outage verification process, directly grounding.
• Unlocking the anti-misoperation interlock and forcibly closing the grounding switch while the power is on.

3.3. Safety Hazards

• Direct grounding while the power is on will instantly create a metallic three-phase short circuit.
• It will generate a powerful electric arc and a violent explosion, burning down switchgear and busbars.
• Arc flash can easily cause burns and high-voltage electric shock injuries.
• It can impact the power grid system and cause large-scale power outages.

3.4. Standard Operating Procedures

• Strictly adhere to the standard procedure: Power outage → Voltage verification → Confirmation of no power → Connecting the grounding wire/closing the grounding switch.
• Strictly follow: No grounding operation is allowed without voltage verification and confirmation of no power.

4. It is strictly prohibited to close the circuit breaker (suppress power) with the grounding wire (grounding switch) connected.

4.1. Explanation of the Prohibition:

• After equipment maintenance, if the temporary grounding wire has not been removed and the grounding switch inside the cabinet is still in the closed position, it is strictly prohibited to forcibly close the circuit breaker or forcibly energize it.

4.2. Prohibited Violations:

• Failure to inventory and remove the temporary grounding wire after maintenance, and then directly closing the circuit breaker to energize it.
• Failure to open and reset the grounding switch, and then blindly closing the circuit breaker to energize it.
• Forgetting to remove the grounding wire or open the grounding switch, and then forcibly energizing it.
• Unauthorized unlocking of the anti-misoperation interlocking device, and then forcibly closing the circuit breaker with the ground wire connected.

4.3. Safety Hazards

• Closing the circuit breaker with the grounding wire connected instantly causes a metallic ground fault.
• Generates a huge short-circuit current and a strong electric arc, potentially causing switchgear explosions and equipment burnout.
• Highly likely to cause electric arc burns and high-voltage electric shock injuries.
• Impacts the power grid, causing widespread power outages and escalating accidents.

4.4. Standard Operating Procedures

• Before energizing, the following must be done: Thorough inspection → Remove all temporary grounding wires → Open the grounding switch → Only after confirming there is no grounding can the circuit breaker be closed to energize.
• Strictly adhere to the rule: Remove grounding wires before energizing; closing the circuit breaker with the grounding wire connected is strictly prohibited.

5. Prohibition of Entering Live Enclosures

5.1. Explanation of Prohibitions

• Unauthorized opening of cabinet doors, unauthorized entry, or unauthorized entry into cabinet compartments, busbar rooms, and cable rooms where high-voltage switchgear is operating is strictly prohibited. Unauthorized entry into high-voltage live compartments is strictly prohibited without power de-energization, voltage testing, and grounding wire installation.

5.2. Prohibited Violations

• Unauthorized opening of high-voltage switchgear cabinet doors without permission or a work permit.
• Entering a live switchgear cabinet due to misreading the cabinet number or entering the wrong bay.
• Unauthorized damage or unlocking of cabinet locks/anti-misoperation interlocks to forcibly open live bay doors.
• Unauthorized entry into the live area of ​​a high-voltage switchgear cabinet by a single person without supervision.

5.3. Safety Hazards

• Approaching high-voltage live parts at close range greatly increases the risk of high-voltage electric shock and step voltage electric shock.
• This can cause phase-to-phase arcing short circuits, arc burns, and instantaneous serious injury or death.
• This can cause equipment short circuits, power outages, and escalation of the accident.

5.4. Standard Operating Procedures

• Strictly verify equipment names, cabinet numbers, and bay numbers.
• High-voltage bays must be de-energized, tested for voltage, grounded, and marked with warning barriers before entry.
• Strictly adhere to the work permit system, with dedicated supervision; single-person operation is strictly prohibited.
• Unlocking or damaging anti-misoperation interlock devices is strictly prohibited.

The above five hazardous operations are the bottom-line requirements for ensuring the safe operation of Huihai high-voltage switchgear, and are also key principles for protecting the personal safety of operators and preventing equipment failures and power grid accidents. All relevant personnel are urged to remember the prohibitions, operate in accordance with regulations, strictly implement the "two-ticket, three-system" and dual-person supervision system, properly maintain the equipment's anti-misoperation interlocking devices, and consciously avoid violations. Only by strictly adhering to all safety regulations can the reliable performance of Huihai high-voltage switchgear be fully utilized, ensuring the safe, efficient, and stable operation of the power distribution system.

Written by

Huihai Electric Co., Ltd.

Editor Xu

www.huihai-electric.com

WhatsApp:+86 139 1136 0187

Email:13705388456@163.com