ZWJ-12 series High-Voltage Prepaid Metering Box Overview

The ZWJ-12 High-Voltage Prepaid Metering Box is a load control metering device primarily designed for 10kV rated voltage systems with a frequency of 50Hz and a capacity of up to 5000kVA. It serves to control and measure electrical load, enabling high-voltage power measurement and prepaid functionality. When integrated with load control terminals or other controllers, it can achieve load management, high-voltage metering, prepaid functionality, overload current protection, and anti-theft features.

The ZWJ-12 and ZWJ-12GY models consist of ZW8-12 vacuum circuit breakers, dry-type voltage transformers (PT), and current transformers (CT). Their modular structure allows for flexibility, with the upper chamber housing the circuit breaker and the lower chamber accommodating transformers. Options for integrated or separated installations ensure adaptability to varied operational needs. Their robust design and durable construction provide reliable performance and seamless functionality in high-voltage environments.

The ZWJ-12F model is a newly launched product offering advanced remote metering and management capabilities. It enables quick fault location and correction, ensuring uninterrupted power supply and efficient communication between users and the grid. Designed for 12kV systems, it is ideal for urban, rural, and agricultural applications, featuring load control, energy metering, and protection functionalities.

The ZWJ-12LD model, specifically tailored for rural grid upgrades, is suitable for areas requiring prepaid functionality and multi-functional energy metering. Its rugged construction, compact design, and additional features like short-circuit and over-voltage protection make it ideal for diverse outdoor applications, including substations, commercial facilities, and rural distribution networks.

ZWJ-12 Metering Box Type Designation

• ZW: Outdoor vacuum-sealed design for reliability and insulation.
• J: PT and CT for precision.
• 12: Maximum voltage rating of 12kV.
• :5: Current transformer functionality.
• Z: Combined type for load control and metering.
• G: Designed for energy metering.
• 3: Three-phase three-wire system.

The ZWJ-12/Z3 High-Voltage Prepaid Metering Box is designed to integrate load control and metering functionalities in a single device. It features a vacuum circuit breaker, voltage transformers (PT), and current transformers (CT), all housed in a fully sealed epoxy resin structure. This advanced design provides superior insulation performance and ensures reliable operation in high-voltage systems, making it ideal for energy metering, load management, and protection applications.

Structural Characteristics of ZWJ-12 Metering Box

The ZWJ-12 metering box is equipped with a high-performance vacuum circuit breaker, offering integration of switching and metering functionalities. Its simple structure, stable characteristics, flexible operation, and long service life make it reliable and easy to maintain. The high-capacity circuit breaker ensures safe and efficient operation under various conditions.

Optional intelligent control modules and GSM communication units enable remote communication, data reading, and operation control. This feature enhances operational convenience and allows for seamless integration with modern power management systems.

The device supports prepaid management functionalities through three-phase electronic meters. It allows remote monitoring, automatic billing, and control of electricity usage, ensuring that users have a reliable and easy-to-use solution. Overload or excessive consumption triggers automatic load disconnection, providing additional safety and convenience.

An integrated current-limiting protection mechanism ensures secure operation, even during power-off states. The box features a locking mechanism that requires a dedicated key for access, offering effective anti-theft protection.

The voltage and current transformers within the metering box are constructed with environmentally friendly epoxy resin, ensuring superior insulation performance. The metering box is fully sealed, corrosion-resistant, and made of stainless steel, providing both durability and aesthetic appeal.

Installation is user-friendly, with circuit breakers and metering components mounted on a dedicated base plate. This compact design eliminates the need for external framing, improving the box’s overall reliability and reducing installation complexity

Service Conditions for ZWJ-12 High-Voltage Metering Box

• Ambient Temperature: -40°C to +55°C, maximum daily variation 25°C.
• Extreme Ambient Temperature: -45°C to +60°C.
• Altitude: ≤ 2000m.
• Seismic Resistance: Earthquake intensity ≤ 8 degrees.
• Wind Pressure: ≤ 700Pa (equivalent to wind speed ≤ 34m/s).
• Air Pollution Level: Class III.
• Ice Cover Thickness: ≤ 10mm.
• Installation Site: Non-flammable, non-explosive, free from chemical corrosion or intense vibration.

Technical Parameters of ZWJ-12 Prepaid Metering Box

• Product Standards:
  • GB 17201-2007: Combined Transformers
  • GB 1984-2003: High Voltage AC Circuit Breakers
• Vacuum Circuit Breaker Specifications: 

Technical Parameters of ZWJ-12 Prepaid Metering Box

Parameter	Value
Maximum Voltage	12kV
Rated Load	5000kVA
Rated Short Circuit Breaking Current (Peak)	50kA
Rated Short-time Withstand Current Duration	4s
Rated Short-time Withstand Current	20kA
Rated Peak Withstand Current	50kA
Control Circuit Voltage	AC220 ± 10%V
Average Opening Speed	1.1 ± 0.2m/s
Average Closing Speed	0.8 ± 0.2m/s
Closing Time	≤ 60ms
Opening Time	≤ 60ms

• Transformer Specifications

Transformer	Rated Transformation Ratio	Rated Capacity & Accuracy Class
Voltage Transformer	10: 0.1:0.22kV	10:0.1kV – 20VA, 0.2 class 10:0.22kV – 50VA, 3 class
Current Transformer	300(150):5 200(100):5 150(75):5 120(60):5 100(50):5 80(40):5 60(30):5 50(25):5 40(20):5 30(15):5 20(10):5 10(5):5	10VA 0.2s class

Key Components and Connections: 

 

Installation and Maintenance

 

1. Pre-Installation Checks: Perform precision and polarity testing before installation to ensure all requirements are met.
2. Wiring Instructions:  The P1 terminal is for input, and the P2 terminal is for output. Ensure proper grounding of the switchgear and metering box, and verify the connection accuracy.
3. Connection Reliability: Ensure that all connections are secure and reliable before energizing the equipment. Follow the installation standards for secondary connection terminals and maintain insulation distances suitable for outdoor installations.
4. Operational Safety: Avoid opening the secondary circuits of the current transformers during operation. Do not leave the secondary circuits of the voltage transformers open.
5. Regular Maintenance: Periodically clean the surface of the metering box to remove dust and debris, ensuring optimal performance.

These steps ensure safe, reliable, and long-lasting operation of the ZWJ-12 metering box.

Ordering Guidelines for Prepaid Load Control Metering Box

1. Model and Type: Specify the model (e.g., ZWJ-12) and type (e.g., load control, metering).
2. Voltage and Current Ratings: Provide the rated voltage (e.g., 12kV) and primary/secondary current ratios.
3. Accuracy Class and Capacity: Indicate the required accuracy class (e.g., 0.2, 0.5) and capacity (e.g., 10VA, 20VA).
4. Customization Options: For specific requirements, including voltage/current transformer casings and precision levels, customization is available.

Providing these details ensures the metering box meets your specific operational needs. Contact us for tailored solutions!

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