Overview
The JLSZK-12 IV is a high-voltage prepaid metering box rated for 6–10 kV systems with an equipment voltage class of Um 12 kV. It features an oil-free, cast-resin insulation system and integrates a ZW8-12 vacuum circuit breaker with built-in current and voltage transformers in a single outdoor-rated enclosure.
Designed for revenue-grade metering, it delivers 0.2S-class CT and 0.2-class PT accuracy, supporting applications such as rural overhead distribution, substation boundary metering, industrial feeders, and distributed generation interconnection. The unit complies with key standards including GB 1207-2006, GB 1208-2006, GB 1984-2003, and IEC 56.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| System voltage | 6 kV or 10 kV (Um 12 kV) |
| Rated frequency | 50 Hz |
| Rated current | 630 A |
| CT ratio | 5–800/5 A (multi-ratio, 5 A standard) |
| PT ratio | 10000/100 V (standard) |
| Metering accuracy | CT: 0.2S; PT: 0.2 |
| Rated burden | PT: 2×20 VA; CT: 2×10 VA |
| Short-circuit breaking current | 12.5 / 16 / 20 kA |
| Peak withstand current | 31.5 / 40 / 50 kA |
| Short-time withstand current | 12.5 / 16 / 20 kA, 4 s |
| Control voltage | AC/DC 110 V or 220 V |
| Standards | GB 1207, GB 1208, GB 1984, DL/T 403, IEC 56 |
Model Designation
- J: Voltage transformer (VT/PT) function integrated
- L: Current transformer (CT) function integrated
- S: Three-phase configuration
- Z: Dry-type insulation structure (oil-free)
- K: Vacuum switching device integrated
- 12: Rated voltage class Um 12 kV
- F: Prepaid metering and load control function
Construction
The JLSZK-12 IV employs a three-phase common-box design suitable for outdoor installation. It integrates the ZW8-12 vacuum circuit breaker with a spring-stored energy operating mechanism, along with epoxy resin-insulated current and voltage transformers in a sealed, oil-free structure. The housing is constructed from stainless steel or galvanized aluminum with anti-corrosion treatment, ensuring durability under outdoor environmental conditions. The unit includes safety interlocks, local manual operation capability (where permitted by design), and provisions for electrical control via auxiliary power. Instrument transformer windings are clearly marked per standard conventions, and CT secondary circuits must never be opened while the primary is energized.
Technical Parameters
Service Conditions
- Installation environment: Outdoor installation with weather-resistant enclosure
- Altitude: ≤2000 m above sea level
- Ambient temperature: −35°C to +40°C
- Relative humidity: Daily average ≤90%, monthly average ≤90%
- Water vapor pressure: Daily ≤2.2 kPa, monthly ≤1.8 kPa
- Seismic resistance: ≤8 degree earthquake intensity
- Pollution level: Grade III
Technical Parameters
The JLSZK-12 IV high-voltage prepaid metering box is designed for 6–10 kV outdoor distribution systems with a 12 kV insulation level. It operates within an ambient temperature range of −35°C to +40°C and at altitudes up to 2000 m, complying with standard requirements for cast-resin insulated metering equipment. The unit supports rated currents up to 630 A and integrates precision current and voltage transformers for accurate energy measurement.
Main Technical Data
| No. | Item | Unit | Value |
|---|---|---|---|
| 1 | Rated voltage class (Um) | kV | 12 |
| 2 | Rated current | A | 630 |
| 3 | Power frequency withstand voltage | kV | 42 |
| 4 | Lightning impulse withstand voltage (peak) | kV | 75 |
| 5 | Rated short-circuit breaking current | kA | 12.5 / 16 / 20 |
| 6 | Rated short-circuit making current (peak) | kA | 31.5 / 40 / 40 |
| 7 | Rated peak withstand current (dynamic) | kA | 31.5 / 40 / 50 |
| 8 | Rated short-time withstand current | kA | 12.5 / 16 / 20 |
| 9 | Rated short-time withstand duration | s | 4 |
| 10 | Operating sequence | — | O-0.3s-CO-180s-CO |
| 11 | Rated short-circuit breaking operations | cycles | 30 |
| 12 | Mechanical life | operations | 10000 |
| 13 | Charging / control voltage | V | AC/DC 110, 220 |
| 14 | Operating voltage – Opening coil | V | AC/DC 110, 220 |
| 15 | Operating voltage – Closing coil | V | AC/DC 110, 220 |
| 16 | Overcurrent trip current | A | 5 |
| 17 | Static contact allowable compression | mm | 3 |
| 18 | Total weight | kg | 150 |
Voltage and Current Transformer Ratings
| PT Ratio (V) |
CT Ratio (A) |
PT Accuracy |
CT Accuracy |
PT Output (VA) |
CT Output (VA) |
|---|---|---|---|---|---|
| 10000/100 | 5~800/5 | 0.2 | 0.2S | 2×20 | 2×10 |
Installation & Wiring
Installation Diagram
The JLSZK-12 IV High Voltage Prepaid Metering Box is installed outdoors using the designated fixing holes shown in the outline dimensions drawing. Mount the unit securely with outdoor-rated, corrosion-resistant hardware. Primary connections must use outdoor-rated insulated conductors, terminals, or bus connections per site practice, while maintaining required electrical clearances for safe operation. Control and communication wiring should be routed through sealed cable entries to preserve the enclosure’s protection rating.
Selection & FAQs
Selection Guide
- Confirm the 6kV or 10kV network, 12kV equipment class, 630A rating, and required fault-breaking level.
- Select the 5–800/5A CT ratio from the load profile and verify class 0.2S metering burden.
- Confirm the PT ratio, class 0.2 output, prepaid meter, trip logic, auxiliary voltage, and control interface.
- Define temperature, altitude, pollution, seismic, corrosion, ingress protection, and communication requirements.
- Verify mounting, clearances, terminals, cable sealing, grounding, interlocks, commissioning, and utility approval.
Frequently Asked Questions
Q1: Can this metering box operate in extreme cold environments?
Yes, it operates in ambient temperatures from −35°C to +40°C. The cast-resin insulated enclosure ensures reliable performance in severe weather. Confirm specific cold-region requirements with our engineers.
Q2: What is the maximum installation altitude for this 12kV metering box?
The maximum installation altitude is 2000 meters above sea level. For higher elevations, derating or custom insulation design is required. Please contact us for altitude-specific technical confirmation.
Q3: Which rated current capacity does this high-voltage prepaid metering box support?
It supports a maximum rated current of 630 A. The unit integrates precision transformers for 6–10 kV distribution systems. Verify exact transformer ratios for your specific load requirements.
Q4: Can we customize the transformer ratios for this outdoor metering box?
Customization is available subject to factory confirmation. We can adjust current and voltage transformer ratios to match your specific 6-10kV system needs. Contact our sales team with your technical specifications.
Q5: What factory tests are performed before shipping the JLSZK-12 IV?
Standard routine tests include the 42 kV power frequency withstand voltage. Full type test reports and specific routine test details are available upon request. Contact us for detailed test certificates.
Q6: Is this equipment suitable for outdoor 10kV distribution networks?
Yes, it is specifically designed for 6–10 kV outdoor distribution systems. The weather-resistant enclosure and Grade III pollution rating ensure reliable outdoor operation. Review our product category for similar high-voltage metering equipment.
Q7: How does this metering box perform in high seismic activity zones?
It withstands seismic intensities up to 8 degrees. The robust cast-resin insulation and secure outdoor enclosure maintain structural integrity during earthquakes. Confirm local seismic codes with our engineering team.