Product Overview
Functional Definition
The JSZW-10R 10kV Outdoor Epoxy Resin Combined Transformers, are high-performance electromagnetic instruments, designed for accurate voltage and current measurement, energy metering, voltage monitoring, and relay protection in 10 kV outdoor power distribution systems. This integrated transformer combines voltage transformation and current sensing functions in a compact, fully-enclosed epoxy resin structure, providing galvanically isolated secondary signals proportional to primary voltage and current.
Key Ratings
| Item | Specification (per order / nameplate) |
|---|---|
| System voltage class | 10 kV class (outdoor distribution and substation applications) |
| Rated frequency | 50 Hz (60 Hz available upon request) |
| Rated voltage ratio | 10000/√3 / 100/√3 / 100/√3 (V) or as specified |
| Secondary voltage | 100/√3 V (dual secondary windings configuration) |
| Accuracy classes | 0.2 / 0.5 / 1.0 (metering); 6P (protection) |
| Rated burden | 15 VA / 30 VA / 60 VA (per winding as specified) |
| Protection burden | 50 VA (6P class) |
| Maximum output | 300 VA |
| Burden power factor | cosφ = 0.8 (lagging) unless otherwise specified |
| Insulation level | 12/42/75 kV (Um/Up/Ud per IEC 60071-1) |
| Winding configuration | Yo/Yo/△ or Yo/Yo/Yo/△ as specified |
| Built-in protection | High-voltage fuses (HV side protection) |
| Applicable standards | IEC 61869-3 / IEC 61869-5; GB/T 20840.3 / 20840.5; JB/T 5277 |
| Installation environment | Outdoor pole-mounted or platform-mounted installation |
Product Shows
Working Principle
Operating on electromagnetic induction principles, the JSZW-10R combined transformer integrates voltage transformation and current sensing in a single unit. The voltage transformer section uses primary and secondary windings wound on a magnetic core, with primary voltage inducing proportional secondary voltage through magnetic coupling. The integrated current sensing component (where applicable in combined configuration) provides additional current measurement capability. The fully-enclosed epoxy resin structure ensures reliable insulation and environmental protection for outdoor service.
System Application Position
- Outdoor Distribution: 10 kV overhead line systems and outdoor substations
- Energy Metering: Revenue-grade electricity measurement in rural and industrial grids
- Voltage Monitoring: System voltage regulation and quality monitoring
- Protection Circuits: Overvoltage, undervoltage, and earth fault protection schemes
- SCADA Integration: Remote monitoring and control systems
Structural Overview
Fully-enclosed epoxy resin cast construction provides superior insulation performance, moisture resistance, UV resistance, and mechanical strength for long-term outdoor service. The pole-mounted configuration enables installation on outdoor distribution poles or platform structures, with integrated high-voltage fuses providing primary-side short-circuit protection. The sealed design eliminates internal condensation and contamination risks while maintaining stable electrical performance across varying environmental conditions.
Model Designation
Model Code Explanation
- J — Voltage transformer (VT) function included
- S — Three-phase configuration
- Z — Cast-resin (epoxy) insulated, fully enclosed structure
- W — Outdoor application design
- 10 — Voltage class (kV)
- R — Built-in fuse protection (Rong-duan-qi)
Configuration Types
JSZW-10R is available in two primary winding configurations:
- Yo/Yo/△: Standard configuration with dual voltage secondaries and auxiliary delta winding
- Yo/Yo/Yo/△: Extended configuration with three voltage secondaries and auxiliary delta winding
The delta-connected auxiliary winding provides zero-sequence voltage detection capability for earth fault protection applications. Selection between configurations depends on metering, monitoring, and protection circuit requirements specified by the project.
Service Conditions
The JSZW-10R combined voltage transformer is designed for outdoor operation under normal service conditions in medium-voltage power distribution systems.
- Installation environment: Outdoor installation on poles or platforms
- Altitude: Not exceeding 1000 m above sea level (higher altitude shall be specified for engineering confirmation and altitude correction factors)
- Ambient temperature: −25 °C to +40 °C (extended range −40 °C to +40 °C available upon request)
- Relative humidity: Daily average ≤ 95%, monthly average ≤ 90% (at +25 °C reference)
- Environmental conditions: Suitable for outdoor exposure to rain, snow, wind, UV radiation, and moderate pollution; free from corrosive gases, explosive media, or severe mechanical vibration
- Pollution level: Designed for moderate pollution environments; heavier pollution levels require additional specification
- Seismic resistance: Suitable for areas with seismic intensity ≤ 8 degrees (higher intensity requires engineering confirmation)
Construction
Construction Design
- Structure: Pole-mounted or platform-mounted outdoor design
- Insulation: Fully-enclosed epoxy resin cast insulation system
- Core: High-permeability magnetic core for voltage transformation
- Windings: Integrated primary and multiple secondary windings
- Protection: Built-in high-voltage fuses on primary side
- Terminals: Weather-sealed terminal compartment with porcelain or composite insulators
- Mounting: Integrated mounting bracket for pole or platform installation
The epoxy resin casting provides stable insulation properties and resistance to moisture, UV degradation, pollution, temperature cycling, and aging for long-term outdoor service. The sealed construction eliminates oil maintenance requirements and reduces environmental impact.
Windings & Terminal Marking
- Primary terminals: A / B / C (high-voltage connections)
- Secondary terminals (metering winding 1): a1 / b1 / c1 / n1
- Secondary terminals (metering winding 2): a2 / b2 / c2 / n2
- Secondary terminals (auxiliary delta winding): ad / bd / cd (or ax / bx / cx)
Terminal markings follow standard VT polarity conventions per IEC 61869-3. Under normal operating conditions, terminals with matching subscripts (A-a1, B-b1, C-c1) are in-phase. Correct terminal identification and grounding shall be observed to ensure metering and protection performance. The neutral point of secondary windings (n1, n2) shall be reliably grounded at one point per applicable standards.
Technical Data
This section provides selection-oriented technical data for the JSZW-10R outdoor combined voltage transformer used in 10 kV class AC systems (50 Hz). Data shown below is intended for preliminary selection of voltage ratio, accuracy class combinations, rated burdens, and insulation level.
Definitions: Accuracy class indicates transformer performance per IEC 61869-3 (voltage factor range, phase displacement, ratio error limits). Rated burden (VA) is the power that the transformer can supply to the secondary circuit at rated voltage and accuracy. Voltage factor is the maximum continuous operating voltage as a ratio of rated voltage.
Notation: Insulation levels follow Um/Up/Ud notation where Um = maximum system voltage, Up = lightning impulse withstand voltage, Ud = power-frequency withstand voltage. Acceptance shall be based on nameplate values and factory test report.
Data Reference
| Type | Rated VoltageRatio (V) |
Accuracy Class & Rated Output (VA) |
Max Output (VA) |
Rated Insulation Level (KV) |
|||
|---|---|---|---|---|---|---|---|
| 0.2 | 0.5 | 1 | 6p | ||||
| JSZW-10r | 10000/3/100/3/100/3 | 15 | 30 | 60 | 50 | 300 | 12/42/75 |
| JSZW-6r | 6000/3/100/3 | 7.2/32/60 | |||||
| JSZW-3r | 3000/3/100/3 | 3.6/20/40 | |||||
Standards & Normative References
| Standard | Title | Application |
|---|---|---|
| IEC 61869-1 | Instrument Transformers – Part 1: General Requirements | General requirements |
| IEC 61869-3 | Instrument Transformers – Part 3: Additional Requirements for Inductive Voltage Transformers | VT-specific requirements |
| IEC 61869-5 | Instrument Transformers – Part 5: Additional Requirements for Capacitor Voltage Transformers | Reference for combined transformers (where applicable) |
| GB/T 20840.1 | Instrument Transformers – Part 1: General Requirements | National standard (aligned with IEC 61869 framework) |
| GB/T 20840.3 | Instrument Transformers – Part 3: Inductive Voltage Transformers | National VT requirements (aligned with IEC 61869-3) |
| GB/T 20840.5 | Instrument Transformers – Part 5: Capacitor Voltage Transformers | Reference standard for combined configurations |
| JB/T 5277 | Instrument Transformers for Outdoor Installation | Outdoor application requirements |
| IEC 60071-1 | Insulation Co-ordination – Part 1: Definitions, Principles and Rules | Insulation level specification |
| IEC 60694 | Common Specifications for High-Voltage Switchgear and Controlgear Standards | General HV equipment requirements |
| IEC 60529 | Degrees of Protection Provided by Enclosures (IP Code) | Environmental protection rating (outdoor applications) |
| GB 311.1 | Insulation Co-ordination for High-Voltage Transmission and Distribution Equipment | National insulation coordination standard |
Factory Testing Compliance
- Routine tests per applicable IEC/GB requirements including polarity/marking verification, voltage ratio verification, accuracy verification per specified class and burden, and phase displacement measurement
- Dielectric tests including power-frequency withstand test and lightning impulse withstand test per insulation coordination requirements
- Partial discharge test where specified by project requirement (applicable for indoor installation or special applications)
- Temperature rise test for continuous rated burden and maximum output verification
- Fuse operation test to verify proper coordination of built-in high-voltage fuses
- Visual and dimensional inspection including marking and workmanship conformity
- Type and special tests as required by project specification (may include short-circuit withstand, seismic qualification, pollution performance, etc.)
Installation & Dimensions
- Outline dimensions and mounting details are provided in the dimensional drawings.
- The transformer shall be securely mounted using the designated mounting bracket and fixing hardware appropriate for pole or platform installation.
- Primary connections shall be made via overhead line conductors or busbar, ensuring adequate mechanical strength and electrical contact.
- Secondary terminals shall be accessed through the weather-sealed terminal compartment; all secondary wiring shall be protected from environmental exposure.
- Adequate clearance shall be maintained for insulation, heat dissipation, maintenance access, and live-line working procedures.
- Installation height shall provide required electrical clearance to ground and adjacent structures per applicable safety codes.
Outline Dimensions
JSZW-10R Dimensional Drawing
Connection Schematic for Yo/Yo/△ Configuration
Safety Notes
- One point of each secondary winding neutral (n1, n2) shall be reliably grounded in accordance with applicable standards and local regulations.
- Do not exceed rated burden on any secondary winding, as this may cause overheating and accuracy degradation.
- Before connecting or disconnecting secondary circuits, verify that primary circuit is de-energized or use appropriate isolation procedures.
- Built-in HV fuses protect against primary-side short circuits; verify fuse integrity during periodic inspections.
- During installation, verify proper phase sequence and polarity before energization to prevent metering and protection malfunctions.
- All installation, commissioning, and maintenance work shall comply with local electrical safety regulations and utility standards.
- Use proper personal protective equipment (PPE) and isolation procedures when working on or near energized equipment.
Ordering Information
When placing an order, the required configuration shall be specified according to the local grid requirements, applicable standards, and project technical specification. The following parameters shall be clearly stated for technical confirmation and production release:
- Rated voltage ratio (primary voltage / secondary voltage for each winding)
- Winding configuration (Yo/Yo/△ or Yo/Yo/Yo/△)
- Application and accuracy requirements (metering accuracy class for each metering winding; protection accuracy for protection winding)
- Rated burden (VA) for each secondary winding
- Insulation level (if different from standard 12/42/75 kV)
- Rated frequency (50 Hz or 60 Hz)
- Environmental conditions (if extreme temperature, altitude, pollution, or seismic requirements apply)
- Special requirements (if any special terminals, mounting arrangements, or additional testing required)
If local utility or project requirements apply (e.g., special testing, documentation language, certification requirements, or mounting arrangements), specify them at the ordering stage. Special configurations shall be confirmed by technical agreement and final data sheet prior to production.