Huanghua Group Co., Ltd. 
Home Products Circuit Breaker High-voltage circuit-breaker ZW7-40.5 Outdoor AC High-Voltage Vacuum Circuit Breaker
ZW7-40.5 Outdoor AC High-Voltage Vacuum Circuit Breaker
ZW7-40.5 is a 40.5kV outdoor high-voltage AC vacuum circuit breaker with a porcelain-clad outdoor structure. Using vacuum as the arc-quenching medium, it combines high breaking performance, long mechanical life, minimal maintenance, pollution resistance and seismic robustness. Ideal for 35kV/33kV outdoor substations, industrial feeder protection and oil-free retrofit of legacy substations.
Send Inquiry Highlights
| Item | Description |
| Porcelain-clad outdoor structure | Three-phase independent porcelain bushing support + steel structure frame, meeting the creepage distance and weather resistance requirements of outdoor dirty environments, and preventing small animals and condensation. |
| Vacuum arc-quenching, minimal maintenance | The dielectric strength of the vacuum medium recovers extremely quickly, the arc is extinguished within a very small gap, the contact erosion is extremely low, and it requires almost no maintenance except for periodic lubrication of the mechanism. |
| High breaking performance | Rated short-circuit breaking current 20/25kA, capacitor bank breaking current 400A, no reignition, meets the requirements for feeder, transformer, capacitor bank switching and fast automatic reclosing. |
| Reliable operating mechanism | Optional CD10-III electromagnetic mechanism / CT19BW spring mechanism, electric/manual energy storage, flexible and reliable closing, opening and overcurrent tripping. |
| 10,000 operations mechanical life | With a mechanical life of up to 10,000 cycles, grease insulation filling and independent pole seals, long maintenance cycle and low total life cycle cost. |
| Multiple applications | Covering the construction of new 35kV/33kV outdoor substations, oil-free renovation of old substations, feeder protection for industrial and mining enterprises, and switching of new energy booster substations and capacitor banks. |
Product Features
| Product Features | ||
| Feature | Technical Detail | Customer Value |
| Porcelain-clad outdoor structure | Three independent porcelain pillars on a steel frame, IP55, meets outdoor pollution creepage requirements. | Weather-resistant & anti-fouling — Reliable long-term outdoor operation |
| Vacuum interrupter | Vacuum degree 1e-3~1e-5 Pa; dielectric strength recovers extremely fast, arc extinguished within minimal contact gap | Reliable breaking, minimal contact erosion — Arc medium stays stable |
| Grease-type insulating fill | Poles filled with grease-type insulation and sealed at positive pressure; independently filled, no interconnecting pipes. | Fewer joints, lower leakage risk — Moisture & condensation-proof |
| Optional CTs | Up to four CT coils can be mounted in the lower cabinet, configurable for protection/metering. | Integrated protection & measurement — Cuts external CT costs |
| CD10-III / CT19BW mechanism | CD10-III electromagnetic or CT19BW spring mechanism; electric/manual charging, reliable opening/closing. | Flexible compatibility — Easy O&M across power sources & schemes |
| Excellent breaking performance | Rated short-circuit breaking 20/25kA; capacitor bank breaking 400A with no restrike; supports rapid auto-reclosing. | Versatile switching — Feeders, transformers, capacitor banks |
| Long mechanical life | Mechanical life 10,000 operations; contact gap 22±2mm, overtravel 4±1mm, adjustable via hand hole. | Less downtime, lower lifecycle cost |
| Low maintenance, long interval | Minimal maintenance beyond periodic mechanism lubrication; grease fill + independent sealing ensure long-term reliability. | Unattended-ready — Minimal O&M for remote substations |
| Flexible application | For new 35kV/33kV outdoor substations, oil-free retrofit, industrial feeder protection, renewable energy step-up stations. | Multi-scenario one-box solution — Simplifies selection & spares |
Case Studies
| Project | Scale | Application | Effect |
| New 35kV outdoor substation | ZW7-40.5 × Multiple units, equipped with 35kV incoming and outgoing line feeder protection. | Several ZW7-40.5 units for 35kV line feeder protection | Replaced legacy oil circuit breakers; oil-free, minimal-maintenance outdoor operation with reliable interruption. |
| Oil-free retrofit of legacy substation | Replace the old 35kV oil circuit breaker in the station with ZW7-40.5 | Retrofit existing 35kV oil breakers with ZW7-40.5 | Eliminated oil leakage and fire risks, shortened maintenance cycles, improved supply reliability. |
| 33kV industrial feeder protection | ZW7-40.5 is used for 33kV feeder incoming and outgoing lines in mining/metallurgical enterprises. | ZW7-40.5 for 33kV incoming/outgoing feeders in mining & metallurgy plants | IP55 protection plus high mechanical life suit dusty, vibrating conditions; stable operation. |
Product Parameters
| Parameter (EN) | Value (EN) |
| Type | ZW7-40.5/□-□ |
| Rated voltage | 40.5 kV |
| Maximum operating voltage | 40.5 kV |
| Rated frequency | 50 Hz |
| Rated normal current | 630 / 1250 / 1600/2000 A |
| Rated short-circuit breaking current | 20 / 25 kA |
| Rated short-circuit making current (peak) | 50 / 63 kA |
| Rated short-time withstand current (3s) | 20 / 25 kA |
| Rated peak withstand current | 50 / 63 kA |
| Rated short-circuit breaking times | ≤ 30 times |
| Rated operating sequence | O-0.3s-CO-180s-CO |
| Rated capacitor bank breaking current | 400 A (no restrike) |
| Closing time | ≤ 80 ms |
| Opening time | ≤ 60 ms |
| Mechanical life | 10,000 operations |
| Rated power-frequency withstand voltage (1min) | 95 kV (phase-to-earth / across open contacts) |
| Rated lightning impulse withstand voltage | 185 kV peak |
| Auxiliary circuit power-frequency withstand | 2 kV / 1 min |
| Contact gap | 22 ± 2 mm |
| Contact overtravel | 4 ± 1 mm |
| Vacuum interrupter vacuum degree | 1e-3 ~ 1e-5 Pa |
| Operating mechanism | CD10-III electromagnetic / CT19BW spring |
| Spring charging motor voltage | AC/DC 110 / 220 V |
| Opening/closing coil voltage | DC 110 / 220 V |
| Degree of protection | IP55 (IEC 60529) |
| Creepage distance | Meets outdoor pollution class requirements |
| Applicable standards | GB 1984 / IEC 62271-100 / IEC 56 |
| Overall dimensions (L×D×H) | Approx. 2315 × 610 × 2275 mm |
| Installation dimensions | See installation drawing |
| Total weight | Approx. 1000 kg |
| CT configuration | Up to four CT coils in lower cabinet |
| Pole insulation fill | Grease-type insulation, positive-pressure sealed |
| Ambient temperature | -40℃ ~ +40℃ |
| Altitude | ≤ 1000 m (derating if >1000 m) |
| Mounting | Outdoor concrete foundation / steel support |
ZW7-40.5 Installation Outline Diagram
