Overview
The ZWJ-12 is a high-voltage prepaid metering box designed for 10 kV, 50 Hz power distribution systems with capacities up to 5000 kVA. It features a fully enclosed, integrated design combining a vacuum circuit breaker (VCB), voltage transformer (PT), and current transformer (CT) within a cast-resin insulated structure suitable for outdoor or indoor deployment.
Offering Class 0.5S metering accuracy (with 0.2S optional), the unit supports applications in rural grids, urban networks, industrial facilities, and remote sites. It enables revenue protection through prepaid disconnection and smart grid integration via GSM/GPRS, RS485, or Ethernet interfaces. The product complies with IEC 62271-200, GB 17201-2007, and GB 1984-2003 standards.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| System voltage class | 10 kV (6–35 kV available) |
| Rated frequency | 50 Hz |
| Rated current | 630 A (400–1250 A configurable) |
| Short-circuit breaking capacity | 20 kA / 3s (up to 31.5 kA available) |
| Insulation level | 12/42/75 kV (Um/AC/LI per IEC 60071-1) |
| Ambient temperature range | -40°C to +55°C (extended -45°C to +60°C available) |
| Protection rating | IP4X (indoor), IP54 (outdoor) |
| Metering accuracy | Class 0.5S (0.2S optional) |
| Control voltage | AC/DC 110–240 V (24–48 V DC available) |
| Communication interface | GSM/GPRS, RS485, Ethernet (optional) |
| Installation type | Pole-mounted or wall-mounted |
| Applicable standards | IEC 62271-200, GB 17201-2007, GB 1984-2003 |
Model Designation
- Z: Combined instrument transformer (metering box)
- W: Outdoor installation type
- J: Prepaid metering function
- 12: Voltage class designation (10 kV system)
Construction
The ZWJ-12 employs a compact, fully enclosed construction integrating all high-voltage and control components into a single weather-resistant enclosure made of 304 stainless steel or hot-dip galvanized steel with ≥80μm zinc coating. Internal compartments are segregated to isolate high-voltage circuits from low-voltage control and communication sections, enhancing safety and electromagnetic compatibility. The design uses epoxy resin insulation with UV stabilizers for outdoor durability and silicone-based gaskets rated for -50°C to +120°C. Mechanical features include lockable access doors with safety interlocks, natural convection cooling, integrated cable trays, and seismic resistance up to 0.3g per IEC 60068-2-57. All windings comply with IEC 61869, and terminals are clearly marked (K1/K2 for CT, A/X for PT) following international standards.
Technical Parameters
Service Conditions
- Installation environments: Rural areas, urban settings, industrial sites, coastal regions, and high-altitude locations.
- Environmental adaptations: Extended temperature range components, humidity protection with desiccant breathers, enhanced corrosion resistance with stainless steel construction, UV-stabilized materials, and dust/sand protection with enhanced sealing.
Technical Parameters
The ZWJ-12 High Voltage Prepaid Metering Box is designed for 10 kV AC (50 Hz) systems with cast-resin insulation, operating across extended temperature ranges and altitudes up to 3000 m. It complies fully with IEC 62271-1, IEC 62271-100, and IEC 60270 standards, supporting primary current ratings from 400 A to 1250 A.
Model Variants
| Model | Width (mm) |
Height (mm) |
Depth (mm) |
Weight (kg) |
|---|---|---|---|---|
| ZWJ-12 | 800 | 1200 | 600 | 180 |
| ZWJ-12F | 850 | 1250 | 650 | 200 |
| ZWJ-12LD | 900 | 1300 | 700 | 220 |
Voltage Transformer Data
| Parameter | Metering PT | Control PT |
|---|---|---|
| Primary voltage | 10000/√3 V | 10000/√3 V |
| Secondary voltage | 100/√3 V | 100/3 V |
| Accuracy class | 0.5 | 3P |
| Burden (VA) | 30 | 50 |
| Rated Insulation Level (kV) | 12/42/75 | 12/42/75 |
Current Transformer Data
| Parameter | Specification |
|---|---|
| Rated Primary Current | 400/5, 630/5, 800/5,
1000/5, 1250/5 |
| Rated Secondary Current | 5A |
| Accuracy Class | 10P15 / 0.5S |
| Burden (VA) | 15 (metering), 30 (protection) |
| Rated Insulation Level (kV) | 12/42/75 |
Installation & Wiring
Installation Diagram
The ZWJ-12 High Voltage Prepaid Metering Box is installed as a complete outdoor unit, typically mounted on a pole or substation structure. The installation involves secure mechanical mounting, proper electrical termination of primary and secondary circuits, and connection to the grounding system in accordance with local codes.
Selection & FAQs
Selection Guide
- Confirm the 10kV network, prepaid operating logic, rated current, fault duty, and required breaker control sequence.
- Select the 400/5A–1250/5A CT ratio, metering accuracy, protection core, PT ratio, and secondary burdens.
- Define the meter, payment platform, communication interface, remote trip logic, auxiliary voltage, and cybersecurity requirements.
- Choose the enclosure variant and confirm temperature, altitude, corrosion, ingress protection, and seismic conditions.
- Verify pole or structure loading, cable entries, clearances, grounding, interlocks, commissioning tests, and communication coverage.
Frequently Asked Questions
Q1: What maximum altitude is this 10kV metering box rated for?
The ZWJ-12 operates reliably at altitudes up to 3000 meters. It features cast-resin insulation designed for extended temperature ranges. Contact us for derating factors at higher elevations.
Q2: How does the enclosure protect against coastal and high-humidity environments?
It utilizes stainless steel construction for enhanced corrosion resistance and desiccant breathers for humidity protection. UV-stabilized materials and enhanced sealing provide dust and sand defense. Specify exact environmental conditions for factory verification.
Q3: Which primary voltage rating applies to the metering and control PTs?
Both the metering and control voltage transformers feature a primary voltage of 10000/√3 V. This ensures accurate step-down for 10 kV AC systems. Request specific secondary burden details from our engineering team.
Q4: What are the dimensional differences between the standard and F-model variants?
The ZWJ-12F model is slightly larger, measuring 850x1250x650 mm and weighing 200 kg compared to the standard 800x1200x600 mm, 180 kg unit. The ZWJ-12LD variant increases further to 900x1300x700 mm and 220 kg.
Q5: Which international standards does this high-voltage prepaid metering box comply with?
The equipment fully complies with IEC 62271-1, IEC 62271-100, and IEC 60270 standards. These certifications ensure safe operation in 10 kV AC, 50 Hz networks. Request the official type test reports for your tender.
Q6: Where can this high-voltage prepaid metering box be deployed?
The ZWJ-12 series is deployed across rural areas, urban settings, industrial sites, and coastal regions. Its robust design supports primary current ratings from 400 A to 1250 A.
Q7: What primary current ratings are supported by the integrated current transformers?
Standard models support primary current ratings from 400 A to 1250 A. These ratings ensure accurate metering and protection coordination across extended temperature ranges. Specify your exact load profile for factory verification.
Q8: Why is this 10kV metering equipment suitable for harsh environments?
It is suitable for harsh environments due to stainless steel construction and enhanced sealing. UV-stabilized materials and desiccant breathers ensure reliable operation in coastal and high-altitude locations.