Product Overview
The JLSZV-6/10 Three-Phase Three-Wire Dry-Type Metering Unit is an integrated high-voltage metering device designed for indoor and outdoor 6 kV and 10 kV AC power systems.
Manufactured using an epoxy resin vacuum-casting process, the unit integrates voltage transformers and current transformers within a single cast body, enabling simultaneous voltage and current signal acquisition.
It is mainly used for energy metering, electrical parameter monitoring, and load management in three-phase three-wire distribution systems. Typical applications include 6 kV and 10 kV distribution lines, box-type substations, switching stations, industrial and mining enterprises, commercial buildings, and other medium-voltage power systems.
Product Features
Insulation and Electrical Performance
- Integrated cast-resin insulation:
The voltage and current transformer components are integrally formed using an epoxy resin vacuum-casting process. The solid insulation contains no internal air gaps and provides excellent dielectric performance. - High insulation withstand capability:
The unit can withstand the specified power-frequency and lightning impulse withstand voltage requirements of the corresponding 6 kV or 10 kV system. - Low partial discharge:
Partial discharge is limited to no more than 10 pC, helping reduce insulation ageing and improve long-term operational reliability. - Oil-free dry-type construction:
The product contains no insulating oil, eliminating the risks of oil leakage, oil contamination, and oil-related fire hazards. It is suitable for both indoor and outdoor oil-free power distribution systems. - Simultaneous voltage and current acquisition:
The unit integrates three-phase voltage transformers and two-phase current transformers in accordance with a three-phase three-wire metering arrangement. It simultaneously acquires three-phase voltage and two-phase current signals for energy metering, power calculation, and load monitoring. - Wide ratio range:
Voltage ratios such as 6/0.1 kV and 10/0.1 kV are available. Current ratios from 5/5 A to 2,000/5 A can be configured according to load requirements. - High metering accuracy:
Current transformer accuracy classes up to 0.2S and voltage transformer accuracy classes up to 0.2 are available. Classes 0.5 and 1 can also be supplied according to metering or monitoring requirements. - High pollution-flashover resistance:
The high-voltage side features a multi-shed insulation structure with an extended creepage distance. This improves resistance to surface flashover in humid, polluted, and exposed outdoor environments.
Structural and Installation Features
- Integrated dry-type structure:
The complete metering assembly is enclosed within a single cast-resin body with no exposed internal live components. - Indoor and outdoor versions:
Outdoor models provide an IP65 protection rating, while indoor models provide an IP20 protection rating. - Compact construction:
Integrating the voltage and current transformers into one unit reduces the number of separate components, saves installation space, and simplifies on-site wiring. - Three-phase three-wire metering design:
The unit uses a two-element metering arrangement suitable for three-phase three-wire systems, including systems with non-effectively earthed neutrals. - Direct meter connection:
The secondary circuits can be connected directly to a compatible three-phase three-wire energy meter without requiring additional instrument transformers. - Clearly identified terminals:
The high-voltage side uses dedicated terminals or terminal plates. Secondary voltage and current terminals are clearly marked and grouped separately to reduce the risk of incorrect wiring. - Flexible installation:
The unit supports outdoor pole mounting, indoor switchgear installation, and installation inside box-type substations. - High mechanical stability:
The mounting structure provides reliable resistance to vibration and wind loads when correctly installed.
Operation and Maintenance Features
- Low-maintenance operation:
The dry-type, oil-free design eliminates oil leakage, oil replacement, and oil-related fire risks. - High mechanical strength:
The epoxy resin cast body provides reliable impact resistance, ageing resistance, and corrosion resistance. - Wide operating temperature range:
The unit can operate at ambient temperatures from -40°C to +70°C. The epoxy resin maintains stable insulation and mechanical properties under high- and low-temperature conditions. - Outdoor weather resistance:
Outdoor models can withstand normal sunlight, rain, frost, wind exposure, and temperature variation. - High operational reliability:
The voltage and current transformer components use high-quality magnetic cores and winding materials, providing low operating losses, limited temperature rise, and stable metering accuracy. - Stable long-term accuracy:
The product is designed to minimize accuracy drift during long-term operation.
Technical Specifications
Electrical Parameters
| Parameter | Specification |
|---|---|
| Applicable System Voltage | 6 kV / 10 kV AC, Um = 7.2 kV / 12 kV |
| Rated Frequency | 50 Hz |
| Voltage Ratio | 6/0.1 kV or 10/0.1 kV, customizable |
| Current Ratio | 5/5 A to 2,000/5 A, customizable |
| Voltage Transformer Accuracy Class | Class 0.2 / 0.5 / 1 |
| Current Transformer Accuracy Class | Class 0.2S / 0.5S / 0.5 |
| Power-Frequency Withstand Voltage | 28 kV for 1 minute for 6 kV models; 42 kV for 1 minute for 10 kV models, without breakdown |
| Lightning Impulse Withstand Voltage | 60 kV peak for 6 kV models; 75 kV peak for 10 kV models, without breakdown |
| Partial Discharge | ≤10 pC |
| Insulation Resistance | ≥1,000 MΩ between high voltage, low voltage, and earth |
Structural and Material Parameters
| Parameter | Specification |
|---|---|
| Insulating Medium | Integrated epoxy resin casting |
| Protection Rating | IP65 for outdoor models; IP20 for indoor models |
| Installation Type | Pole mounting, indoor switchgear installation, or box-type substation installation |
| Thermal Class | Class B, 130°C |
Environmental Parameters
| Parameter | Specification |
|---|---|
| Installation Altitude | ≤2,000 m; high-altitude versions available |
| Operating Temperature | -40°C to +70°C |
| Storage Temperature | -40°C to +85°C |
| Relative Humidity | ≤95%, non-condensing |
Applicable Standards
| Standard | Description |
|---|---|
| GB 1207 | Voltage Transformers |
| GB 1208 | Current Transformers |
| GB/T 17215 | Electricity Metering Equipment |
| DL/T 448 | Technical Administrative Code for Electric Energy Metering |
Applications
Applicable Power Systems
The JLSZV-6/10 Metering Unit is suitable for three-phase three-wire 6 kV and 10 kV AC power systems with maximum system voltages of 7.2 kV and 12 kV.
Typical Applications
- Pole-mounted energy metering on outdoor distribution lines
- Energy metering and load monitoring in indoor medium-voltage switchgear
- Box-type substations
- Switching and distribution stations
- 6 kV and 10 kV distribution systems in industrial and mining enterprises
- Commercial buildings and industrial parks
- Energy data acquisition in power automation systems
- Power monitoring, control, and load management systems
Main Functions
The metering unit converts the system high voltage and primary current into standardized secondary signals:
- Voltage output: 100 V
- Current output: 5 A
These signals can be supplied to:
- Three-phase three-wire energy meters
- Metering instruments
- Power monitoring equipment
- Load management systems
- Data acquisition devices
- Power automation systems
The unit supports:
- Energy metering
- Power calculation
- Load monitoring
- Electrical parameter acquisition
- Consumption analysis
- Energy management
It also provides electrical isolation between the primary power system and the secondary metering circuits, helping protect connected equipment and operating personnel.
Operating Conditions
Normal Operating Conditions
- Installation altitude: no more than 2,000 m
- Ambient temperature: -40°C to +70°C
- Severe or sudden temperature changes should be avoided
- Relative humidity: no more than 95%, non-condensing
- The environment should be free from corrosive gases
- Flammable or explosive substances are not permitted
- Severe vibration and mechanical impact should be avoided
- Outdoor models can withstand normal sunlight, rain, frost, and wind exposure
- Outdoor pole-mounted or indoor switchgear installation
- Environments with severe corrosion, salt spray, or sandstorms should be avoided unless a customized model is used
Special Operating Conditions
Customized products are required for:
- Installation altitudes above 2,000 m
- Ambient temperatures outside the range of -40°C to +70°C
- Severe pollution or salt-spray environments
- Chemically corrosive environments
- Strong wind or severe sand and dust conditions
- High-intensity ultraviolet exposure
- Non-standard voltage ratios
- Non-standard current ratios
- Special mounting dimensions
Installation and Maintenance
Installation Requirements
- Pre-installation inspection:
Inspect the metering unit and confirm that the epoxy resin body is free from cracks, bubbles, mechanical damage, and other visible defects. Check that all terminal markings are clear and that the supplied accessories are complete. Verify that the model, voltage ratio, current ratio, and accuracy classes match the system design and metering requirements. - Mounting:
Select a suitable mounting bracket according to the installation method. Secure the metering unit in position and confirm that there is no looseness, displacement, or uneven mechanical loading. The mounting position may be horizontal or vertical according to the product design. Pole-mounted installations must meet the specified wind-load and anti-overturning requirements. - High-voltage-side connection:
Connect the high-voltage terminals according to the system design. Ensure that all connections are securely tightened and provide reliable electrical contact. Maintain adequate electrical clearance between the high-voltage conductors, grounded components, and other live parts. Outdoor high-voltage connections must be properly protected against water ingress and corrosion. - Secondary-side connection:
Connect the voltage and current secondary terminals to the energy meter according to their markings. The current transformer secondary circuit must never be left open while the primary circuit is energized. The voltage transformer secondary circuit must never be short-circuited. The required current secondary circuit must be reliably earthed at one point in accordance with the system design and applicable electrical safety requirements. - Insulation inspection:
After installation, measure the insulation resistance between:- High voltage and low voltage
- High voltage and earth
- Low voltage and earth
Maintenance Requirements
- Regularly inspect the epoxy resin body for cracks, mechanical damage, discharge marks, and contamination.
- Check the high-voltage terminals for looseness, oxidation, corrosion, or abnormal heating.
- For outdoor models, inspect the terminal waterproofing and corrosion protection.
- Regularly check all high-voltage and low-voltage connections for looseness, overheating, and discoloration.
- Confirm that the current secondary circuit remains correctly connected and reliably earthed.
- Periodically verify the metering accuracy by comparing the energy meter readings with the specified metering unit error limits.
- Periodically test the insulation resistance and confirm that the insulation performance remains within the specified requirements.
- Clean dust and contamination from the metering unit surface.
- For outdoor models, regularly clean the insulating sheds to reduce the risk of pollution flashover.
- Prevent oil and corrosive substances from contacting the epoxy resin body.
- If cracking, electrical discharge, overheating, or excessive metering error is detected, immediately de-energize and inspect the equipment. Replace the unit where necessary.
Precautions
- The current transformer secondary circuit must never be left open while the primary system is energized. The voltage transformer secondary circuit must never be short-circuited. Either condition may produce hazardous overvoltage or overcurrent and create a serious risk to equipment and personnel.
- During maintenance, the current secondary circuit must be securely short-circuited and earthed before disconnection. The voltage secondary circuit must be safely isolated before work begins.
- Avoid impact or collision with the epoxy resin body and high-voltage terminals during transportation and installation. Mechanical damage may reduce insulation performance and pollution-flashover resistance.
- Use suitable insulated conductors for high-voltage connections. Maintain adequate electrical clearance from grounded components and other live parts to prevent phase-to-phase or phase-to-earth discharge.
- Confirm the correct phase sequence during three-phase wiring. Incorrect phase connections may affect metering accuracy and system operation.
- The equipment must be reliably earthed. The grounding terminal on the base must be securely connected to the grounding busbar.
- Outdoor models must comply with the applicable lightning protection and earthing requirements.
- Store the product in a dry, ventilated, and shaded environment. Avoid direct sunlight, high temperatures, moisture, compression, and mechanical impact.
- Installation, commissioning, and maintenance must be carried out by qualified electrical personnel in accordance with applicable electrical safety procedures.
- The metering unit must pass verification by the relevant local metrology authority before being put into service where such verification is required.
Standard Supply List
| No. | Item | Function |
|---|---|---|
| 1 | JLSZV-6/10 Three-Phase Three-Wire Dry-Type Metering Unit | Main device for voltage and current transformation, electrical isolation, and energy metering |
| 2 | Mounting Brackets, Bolts, and Washers | Used to secure the metering unit during installation |
| 3 | Secondary Terminal Cover | Protects the low-voltage terminals and helps prevent incorrect connections or short circuits |
| 4 | Product Instruction Manual | Provides installation, operation, maintenance, and metering circuit wiring guidance |
| 5 | Product Certificate, Factory Test Report, and Metrological Verification Certificate | Provides product quality and performance documentation, including voltage-ratio, current-ratio, and accuracy test data |
Applicable Standards and Certification
The product complies with the following standards:
- GB 1207, Voltage Transformers
- GB 1208, Current Transformers
- GB/T 17215, Electricity Metering Equipment
- DL/T 448, Technical Administrative Code for Electric Energy Metering
The product has passed the applicable type tests and metrological verification. Its performance meets the energy metering requirements of 6 kV and 10 kV three-phase three-wire power systems.
