ZW20 Vacuum Circuit Breaker for 12kV Overhead Distribution Networks
XBRELE designs and manufactures outdoor ZW20 vacuum circuit breakers for 12 kV medium-voltage power systems, providing reliable protection and automation for overhead distribution networks. ZW20 series can be configured as automatic reclosers for feeder and transformer protection.
ZW20 vacuum circuit breaker for 12kV overhead networks
The ZW20 vacuum circuit breaker is an outdoor 12 kV switching device for medium-voltage overhead distribution networks. Each ZW20 unit integrates the vacuum interrupter, solid-insulated embedded pole, operating mechanism and current transformers into a compact, fully enclosed body suitable for long-term field operation.
With the embedded pole design, the ZW20 vacuum circuit breaker achieves high insulation level and protects the interrupter from moisture, dust and pollution. Together with a stable spring operating mechanism, it delivers reliable opening and closing performance under frequent switching conditions on distribution feeders.
In standard configuration the ZW20 works as a pole-mounted vacuum circuit breaker. When it is equipped with a suitable controller and sensors, the same ZW20 vacuum circuit breaker can be configured as an automatic recloser for feeder protection and distribution automation on 12 kV networks.
For a broader view of XBRELE’s outdoor vacuum circuit breakers, please visit the vacuum circuit breaker pillar page .
ZW20-12F — specifications and outline drawings
Select the voltage level below to view the corresponding product photo, key electrical ratings, and outline & mounting dimensions for engineering design and selection.
ZW20-12F technical overview
ZW20-12F is an outdoor vacuum recloser for 12kV overhead distribution networks, designed to provide reliable protection and automation. The unit features solid insulation and an embedded pole for enhanced durability and protection.
This recloser integrates a vacuum interrupter and spring operating mechanism, ensuring long-term performance under frequent operations in challenging outdoor environments.
The table below lists the main electrical ratings for ZW20-12F.
Key electrical ratings — ZW20-12F
Values according to the ZW20-12F technical parameter sheet.
| No. | Item | Unit | ZW20-12F |
|---|---|---|---|
| 1 | Rated voltage | kV | 12 |
| 2 | Rated current | A | 630 / 1250 |
| 3 | Rated frequency | Hz | 50 |
| 4 | Rated short-circuit breaking current | kA | 20 / 25 |
| 5 | Rated short-circuit closing current (peak) | kA | 50 / 63 |
| 6 | Mechanical life | operations | 10,000 |
| 7 | Rated operating voltage | V | AC/DC220 |
| 8 | Power-frequency withstand voltage (1 min, phase-to-phase) | kV | 34 |
| 9 | Lightning impulse withstand voltage (phase-to-phase) | kV | 75 / 85 |
| 10 | Weight | kg | ≈ 140 |
| 11 | Rated current cut-off times | times | 10,000 |
| 12 | Rated short-circuit breaking times | times | 30 |
| 13 | Power frequency withstand voltage 1 min | kV | 34 |
| 14 | Lightning impulse withstand voltage | kV | 75/85 |
| 15 | Contact spacing | mm | 9 |
| 16 | Contact stroke of contact | mm | 3 |
| 17 | Average opening speed | m/s | 1.2±0.2 |
| 18 | Average closing speed | m/s | 0.6±0.2 |
| 19 | Rated operating voltage | V | AC/DC220 |
| 20 | SF6 gas rated pressure | MPa | 0 |
Outline & mounting dimensions — ZW20-12F
Outline and mounting dimensions for typical ZW20-12F pole-mounted installation.
| Item | Symbol | Value (mm) | Note |
|---|---|---|---|
| Overall height | H | — | Overall height of breaker assembly |
| Overall width | W | — | Including phase spacing |
| Mounting hole spacing (horizontal) | L1 | — | Base horizontal bolt distance |
| Mounting hole spacing (vertical) | L2 | — | To match cross-arm or steel structure |
| Mounting hole size | Φ | — | Oval or round hole diameter |
Protection, control and automation around the ZW20 series
ZW20 outdoor vacuum reclosers can be combined with protection relays, CTs/VTs and communication devices to form complete pole-mounted switching and automation solutions for distribution networks.
Protection & measuring combinations
Build a complete protection scheme around the ZW20 using your preferred relays and instrument transformers.
- Feeder over-current and earth-fault protection
- Directional / non-directional protection according to system design
- Integrated CTs for metering and protection functions
- Support for recloser curves and sectionalizing logic
Operating & control options
Flexible operating configurations to match manual, local and remote control requirements.
- Spring operating mechanism with motor charging
- Local/remote control selector with clear position indication
- AUX contacts for SCADA status feedback (open/close/ready)
- Compatible with pole-mounted control cabinets and RTUs
Distribution automation & communication
When combined with suitable controllers, ZW20 breakers can be used in automated distribution systems and smart grid projects.
- Support for common protocols via external IEDs (Modbus, IEC 60870-5-104, etc.)
- Remote open/close and status monitoring through SCADA
- Fault location, isolation and service restoration (FLISR) schemes
- Customized wiring and terminal arrangements on request
How XBRELE builds reliable ZW20 outdoor vacuum circuit breakers
Behind every ZW20 unit there is a controlled manufacturing flow – from embedded pole casting to routine testing – designed to ensure long-term reliability on harsh outdoor lines.
From embedded pole to finished breaker
XBRELE manufactures the vacuum interrupter pole assemblies, operating mechanism and housing in a coordinated process. Each step is monitored and recorded for traceability of every ZW20 unit.
- 01
Vacuum interrupter & pole assembly
Vacuum interrupters are checked for stroke, over-travel and resistance, then built into the solid pole.
- 02
Solid insulation casting & curing
Epoxy insulation is degassed, poured and cured to form a compact embedded pole resistant to tracking.
- 03
Mechanism integration & adjustment
The spring mechanism is assembled, lubricated and tuned so speeds, timing and bounce meet ZW20 limits.
- 04
Final assembly & sealing
Poles, CTs, terminals and enclosure parts are combined into a sealed outdoor body with anti-corrosion coating.
- 05
Routine testing & inspection
Each breaker passes electrical, mechanical and dielectric tests before packing and shipment.
Routine tests for every ZW20
Electrical routine tests verify insulation level and switching performance.
Insulation & switching verification
- Power-frequency withstand between phases and to earth
- Lightning impulse withstand on sample basis
- Contact resistance check for each main circuit
- Mechanical operating tests for O / CO sequences
Routine-test records can be supplied with the shipment if required.
Mechanical reliability
- Type-test verification of 10,000 mechanical operations
- Check of opening / closing speeds within limits
- Control of closing bounce time and pole synchronism
- Environmental checks for lubrication and low-temperature duty
Documentation & traceability
- Type-test reports and routine-test certificates
- Factory inspection records with serial number traceability
- Outline drawings & terminal diagrams in editable format
- Recommended maintenance guidelines for field crews
FAT / QAP / ITP witness testing can be arranged for utility or EPC projects.
Lead time and project support for ZW20-12F outdoor vacuum reclosers
XBRELE supplies ZW20-12F outdoor vacuum reclosers and sectionalizers for utility and EPC projects worldwide, with export-ready packing, flexible lead times and technical support for tender and execution stages.
Lead time & minimum order
Standard ZW20-12F configurations can usually be produced within a few weeks after order confirmation and technical clarification.
- Typical lead time: about 20–30 days for standard units
- Small batches for pilot projects are acceptable
- Mixed orders with other XBRELE VCB series can be combined in one shipment
- Urgent requirements can be discussed case by case
Export packing & logistics
ZW20-12F reclosers are packed for long-distance sea or land transport, with protection against vibration, moisture and corrosion.
- Strong export wooden cases with internal fixing of the breaker
- Circuit breaker, controller and CTs packed with clear labels
- Support for FOB, CIF or door-to-port delivery terms
- Shipping documents and packing list prepared according to client’s instructions
Engineering & project support
XBRELE can assist panel builders, OEMs and utilities during selection, tender preparation and project execution for ZW20-12F applications.
- Support with single-line diagrams and equipment schedules
- Outline drawings, wiring diagrams and data sheets for approval
- Type-test reports and routine-test certificates for documentation
- FAT / QAP / ITP witness testing can be arranged when required
Frequently asked questions about the ZW20 vacuum circuit breaker
Below are typical questions from utilities, EPC contractors and distributors when selecting the ZW20 vacuum circuit breaker for 12 kV overhead distribution networks and recloser projects.