In the event of any of the following emergency situations during the operation of a vacuum circuit breaker, the power should be immediately cut off (disconnect the circuit breaker and isolate the power supply) to ensure personal and equipment safety:
I. When Personal Safety is Threatened
Electric Shock Accident: Someone is found to have touched a live part or been electrocuted.
Electrical Fire: A circuit breaker or its connections, or related electrical equipment, catches fire and emits smoke.
Danger to Operating Personnel Safety: Equipment explosion, severe leakage, insulation damage, etc., placing on-duty or operating personnel in a hazardous environment.
II. Serious Equipment Faults or Damage
Severe Abnormalities in the Circuit Breaker Body
Vacuum bulb rupture or severe leakage: May be accompanied by abnormal sounds (such as popping sounds), internal flashover, and abnormal color (such as milky white). This is one of the most dangerous faults, signifying loss of arc-extinguishing capability.
Severe damage or flashover discharge to bushings or insulators: Severe cracks, ruptures, or continuous arc discharge may occur.
Severe overheating, red-hot discoloration, or melting of connection parts: May be caused by excessive contact resistance, posing a fire risk.
Abnormalities in the operating mechanism: Failure to open, failure to close, maloperation, or burnt-out of the opening/closing coil, jamming of the mechanism, or broken springs may occur, resulting in unreliable opening operations.
Protection activated during operation, but the circuit breaker fails to operate: When a short circuit, overcurrent, or other fault occurs in the line or equipment, the relay protection device has issued a opening command, but the vacuum circuit breaker refuses to open. Power must be immediately cut off via the upstream power switch (such as the upstream circuit breaker).
Abnormal internal sounds: Continuous or violent discharge sounds, popping sounds, and hissing sounds indicate that the internal insulation is damaged or in an unstable state.
Abnormal SF6 gas pressure (e.g., for SF6-insulated circuit breakers): If the circuit breaker uses SF6 gas as the insulating medium (e.g., some tank-type circuit breakers), a significant drop in pressure below the alarm value will severely reduce insulation and arc-extinguishing capabilities.
III. Severe Power System Faults
Bus Voltage Loss: The connected busbar loses voltage due to a fault. The faulty busbar should be isolated as soon as possible.
Circuit Breaker Current Exceeds Rated Value and Continues to Rise: Under abnormal conditions without protection coverage, the current severely exceeds the limit, potentially burning out equipment.
System Experiences Instability Phenomena such as Resonance or Oscillation, and the Circuit Breaker is in a Critical Position, Requires Emergency Operation to Resolve the Incident.
Operating Principles and Procedures
Immediate Execution: Upon discovering the above-mentioned emergency, the on-duty personnel should immediately disconnect the circuit breaker themselves (if the control power supply is normal and the circuit breaker is operable), and promptly report to the dispatcher or superior.
Alternative Measures: If the circuit breaker cannot be electrically tripped, a mechanical tripping device (such as an emergency trip button or handle) should be used decisively for local tripping.
Isolate the Power Supply: After tripping, the isolating switches on both sides of the circuit breaker must be immediately opened to completely isolate it from the live parts, forming a clear disconnection point for easy maintenance and to ensure safety.
Activate the Emergency Plan: Follow the on-site operating procedures and emergency response plan to carry out subsequent handling such as personnel evacuation, fire extinguishing, and isolation of the fault area.
Maintain Records and Reports: Record the fault phenomenon, time of occurrence, and operating process in detail, and report to superiors and the dispatching department.
Summary
The core judgment criterion is: any obvious fault signs that directly endanger personal safety or may lead to an expansion of equipment damage or a escalation of a power system accident constitute sufficient conditions for immediate power outage. In this case, "time is safety," so the power outage operation should be executed first, followed by reporting and analysis.
Shaanxi Huadian vacuum circuit breakers utilize high-quality vacuum interrupters with superior sealing and corrosion-resistant treatment, ensuring consistent performance over long-term operation and significantly reducing maintenance frequency and costs. Precise opening and closing control, low operating power consumption, and easy remote monitoring and automated management facilitate the construction of intelligent power distribution networks. Please contact us if needed.
Email:pannie@hdswitchgear.com.
Whatsapp/Wechat:+8618789455087
