In-Depth Guide sa Common nga Mga Suliranan ug mga Paraan sa Pagtungha Alang sa 10kV Vacuum Circuit Breakers
Common Vacuum Circuit Breaker Faults and On-Site Troubleshooting by Electrical Engineers
Tungod kay ang vacuum circuit breakers gigamit kaayo sa industriya sa kuryente, ang performance mahimong magbago-bago gikan sa usa ka manufacturer ngadto sa lain. Ang pipila ka mga modelo naghatag og maayo nga performance, gibag-o lamang ang maintenance, ug nagpadayon sa mataas nga reliable nga pagsumpli sa kuryente. Ang uban nimo mao ang madalas na mga problema, ug ang pipila adunay severe nga mga defect nga mahimong mogawas sa over-level tripping ug large-scale blackouts. Hingpit kita mo-eksplora ang real-world fault handling sa electrical engineers aron makasabot sa practical experience ug masteron ang comprehensive maintenance techniques.
1. Reduced Vacuum in Vacuum Interrupter
1.1 Fault Phenomenon
Ang vacuum circuit breakers nag-interrupt sa current ug nag-extinguish sa arcs sa vacuum interrupter. Pero, ang daghang wala'y built-in qualitative o quantitative vacuum monitoring, kasagaran nagresulta sa vacuum loss nga isip hidden (latent) fault—mas dangerous kaysa obvious failures.
1.2 Root Causes
Defects sa material o manufacturing process sa vacuum bottle, nagresulta sa micro leaks.
Issues sa material o fabrication sa bellows, nagresulta sa leaks human sa repeated operations.
Sa separate-type VCBs (e.g., ang may electromagnetic operating mechanisms), ang large linkage travel nagapekto sa synchronization, bounce, ug over-travel, nag-accelerate sa vacuum degradation.
1.3 Hazards
Ang reduced vacuum severely impairs ang breaker’s ability sa pag-interrupt sa fault currents, drastically shortens service life, ug mahimong mogawas sa explosions.
1.4 Solutions
Human sa scheduled outages, gamiton ang vacuum tester aron perform og qualitative vacuum checks ug confirm adequate vacuum levels.
Replace ang vacuum interrupter kon natukod ang vacuum loss, ug conduct travel, synchronization, ug bounce tests afterward.
1.5 Preventive Measures
Pili ang vacuum breakers gikan sa reputable manufacturers nga may proven, mature designs.
Prefer integrated designs diin ang interrupter ug operating mechanism combined.
Sa patrols, check alang external arcing sa vacuum bottle. Kon present, likely compromised ang vacuum integrity—schedule immediate replacement.
Sa maintenance, always test synchronization, bounce, travel, ug over-travel aron ensure optimal performance.
2. Failure to Trip (Trip Rejection)
2.1 Fault Symptoms
Remote control fails to trip the breaker.
Manual local tripping fails.
Relay protection operates during faults, but the breaker fails to trip.
2.2 Root Causes
Open circuit sa trip control loop.
Open trip coil.
Low operating voltage.
Increased trip coil resistance, reducing tripping force.
Deformed trip rod causing mechanical binding ug reduced force.
Severely deformed trip rod causing complete jamming.
2.3 Hazards
Trip failure during faults leads to over-level tripping, expanding the fault scope ug causing widespread outages.
2.4 Solutions
Check for open circuits sa trip control loop.
Inspect the trip coil for continuity.
Measure trip coil resistance for abnormalities.
Examine the trip rod for deformation.
Verify normal operating voltage.
Replace copper trip rods with steel ones aron prevent deformation.
2.5 Preventive Measures
Operators: Kon trip/close indicator lights are off, immediately check for open control circuits.
Maintenance staff: Sa outages, measure trip coil resistance ug inspect trip rod condition. Replace copper rods with steel.
Perform low-voltage trip/close tests aron ensure reliable operation.
3. Spring Mechanism – Charging Circuit Faults
3.1 Fault Symptoms
After closing, the breaker cannot trip (insufficient energy).
The storage motor runs continuously, risking overheating ug burnout.
3.2 Root Causes
Limit switch installed too low: Cuts motor power before spring is fully charged → insufficient energy for tripping.
Limit switch installed too high: Motor stays energized after full charge.
Faulty limit switch → motor fails to stop.
3.3 Hazards
Incomplete charging may cause trip failure during faults, leading to over-level tripping.
Motor burnout renders the breaker inoperable.
3.4 Solutions
Adjust limit switch position for accurate motor cutoff.
Replace damaged limit switches immediately.
3.5 Preventive Measures
Operators: Monitor the "spring charged" indicator during operation.
Maintenance: After servicing, perform two local trip/close operations to verify proper function.
4. Poor Synchronization & Excessive Contact Bounce
4.1 Fault Phenomenon
This is a hidden fault—only detectable via mechanical characteristic tests (e.g., timing analyzers).
4.2 Root Causes
Poor mechanical quality of the breaker body; repeated operations cause misalignment ug high bounce.
In separate-type breakers, long linkage rods cause uneven force transmission, increasing phase-to-phase timing differences ug bounce.
4.3 Hazards
High bounce or poor synchronization severely impacts fault current interruption, shortens lifespan, ug may cause explosions. Due to its hidden nature, this fault is especially dangerous.
4.4 Solutions
Adjust the length of the three-phase insulating pull rods to bring synchronization ug bounce within acceptable limits (while maintaining proper travel ug over-travel).
If adjustment fails, replace the faulty phase’s vacuum interrupter ug re-adjust.
4.5 Preventive Measures
Replace aging separate-type breakers with integrated (monobloc) designs to reduce failure risks.
During maintenance, always perform mechanical characteristic tests to detect ug resolve issues early.
Final Note: Environmental Protection
Never overlook environmental impacts. Ensure clean, dry, vibration-free, ug temperature-controlled conditions to guarantee safe ug reliable operation of vacuum circuit breakers.
