JDZ12-10R/6R/3R Single-Phase Epoxy Resin Voltage Transformer with fuse

JDZ12-10R/6R/3R Single-Phase Epoxy Resin Voltage Transformer with fuse

Epoxy resin cast VT with integrated fuse, dual 100V/220V outputs for 3-10kV systems

  • Three voltage variants: 10kV, 6kV, 3kV with identical cast-resin construction
  • Dual outputs: 100V metering, 220V control from single primary voltage input
  • Elbow interface, sealed terminals, integrated fuse for pad-mounted applications
  • 0.2/0.5/1/6P accuracy, 1.2Un voltage factor, IEC 61869-3 compliant design

Product Overview

Functional Definition

The JDZW-10R / JDZ12 series voltage transformers are precision electromagnetic instruments designed for accurate voltage measurement, energy metering, and relay protection applications in medium-voltage AC power systems. These transformers utilize electromagnetic induction principles to provide galvanically isolated secondary voltage signals proportional to primary voltage. The series features integrated fuse protection matched to transformer short-circuit capacity, fully-enclosed vacuum cast epoxy resin construction, and dual secondary voltage outputs (100V for metering, 220V for circuit breaker operation).

Key Ratings

Item Specification (per order / nameplate)
System voltage class 10 kV / 6 kV / 3 kV class (indoor/outdoor distribution applications)
Rated frequency 50 Hz or 60 Hz
Rated voltage ratio 10000/100/220 V (JDZ12-10R), 6000/100/220 V (JDZ12-6R), 3000/100/220 V (JDZ12-3R)
Accuracy classes Metering: 0.2, 0.5, 1 / Protection: 6P
Rated output 15 VA to 60 VA (accuracy class dependent)
Maximum output 500 VA
Burden power factor cosφ = 0.8 (lagging)
Voltage factor 1.2 Un continuous operation capability
Insulation level JDZ12-10R: 12/42/75 kV; JDZ12-6R: 7.2/32/60 kV; JDZ12-3R: 3.6/25/40 kV
Thermal class Class E (75K temperature rise limit)
Fuse protection Integrated internal fuse matched to transformer capacity
Applicable standards IEC 61869-1 / IEC 61869-3; GB/T 20840.1 / 20840.3; GB 1207-2006
Model variants JDZ12-10R / JDZ12-6R / JDZ12-3R

Product Shows

JDZ12 10R JDZ12 6R Single Phase Epoxy Resin Voltage Transformer

Working Principle

Operating on Faraday’s law of electromagnetic induction, the voltage transformer features a laminated magnetic core with primary winding connected to system voltage and secondary windings providing standardized output voltages. The magnetic flux generated by primary voltage induces proportional voltage in secondary windings, delivering dual-output configuration (100V for instrumentation, 220V for auxiliary circuits) through connected burden impedance.

System Application Position

  • Medium Voltage Distribution: 3-10kV pad-mounted transformers, ring main units, and switchgear
  • Energy Metering: Revenue-grade electricity measurement systems
  • Protection Circuits: Overvoltage, undervoltage, and distance protection schemes
  • Circuit Breaker Control: 220V auxiliary supply for breaker operation mechanisms
  • SCADA Integration: Supervisory control and voltage monitoring systems

Structural Overview

Vacuum cast epoxy resin construction with fully-enclosed design ensures superior insulation performance, moisture resistance, and mechanical strength. Integrated internal fuse eliminates external fuse requirements, simplifying installation. Primary terminals accommodate 200A elbow-type cable connectors with sealed high-voltage interface. Secondary terminals feature sealed terminal covers with anti-tampering lead seals, suitable for outdoor enclosure applications with enhanced safety against electric shock and unauthorized access.

Model Designation

JDZ12 1063 voltage transformers type 1

Model Code Explanation

  • J — Voltage transformer (VT/PT)
  • D — Single-phase configuration
  • Z — Cast-resin (epoxy) insulated, fully enclosed structure
  • 12 — Design series
  • 10 / 6 / 3 — Voltage class (kV)
  • R — Built-in fuse protection

Variant Differences

JDZ12-10R (10kV), JDZ12-6R (6kV), and JDZ12-3R (3kV) share identical construction principles and electrical performance characteristics. Variants differ in rated voltage, insulation coordination, and physical dimensions matched to respective voltage classes. All variants maintain dual-output configuration (100V/220V) and integrated fuse protection.

Service Conditions

The JDZ12 series voltage transformers are designed for indoor and outdoor operation (with appropriate enclosure) under normal service conditions in medium-voltage power systems.

  • Installation environment: Indoor or outdoor (with sealed enclosure)
  • Altitude: Not exceeding 2000 m above sea level (higher altitude requires engineering confirmation with detailed parameters)
  • Ambient temperature: −5 °C to +40 °C (daily average not exceeding 35 °C)
  • Relative humidity: Daily average ≤ 95%, monthly average ≤ 90% (at +20 °C reference)
  • Environmental conditions: Free from corrosive gases or vapors; free from explosive or flammable media; mechanically robust for complex environments and moderate mechanical stress
Engineering Note: Installation location shall comply with applicable electrical safety regulations. High-altitude installations require voltage and insulation parameter adjustments per project specification.

Construction

Construction Design

  • Structure: Support (post) type for indoor/outdoor switchgear and pad-mounted transformer applications
  • Insulation: Fully enclosed vacuum cast epoxy resin insulation
  • Core: Laminated magnetic core design with high permeability silicon steel
  • Fuse integration: Internal fuse protection matched to transformer thermal and mechanical limits
  • Primary terminals: Sealed elbow-type cable connector interface (200A rating)
  • Secondary terminals: Sealed terminal box with anti-tampering lead seal provisions

The vacuum cast epoxy resin provides stable insulation properties, excellent moisture resistance, contamination immunity, and long-term aging resistance for harsh outdoor and enclosed indoor environments.

Windings & Terminal Marking

  • Primary terminals: A / X (high-voltage side)
  • Secondary terminals (100V output): a / x
  • Secondary terminals (220V output): ad / xd

Terminal markings follow standard VT polarity conventions. Under normal operating conditions, when primary terminal A is positive with respect to X, secondary terminal ‘a’ is positive with respect to ‘x’. Correct terminal identification shall be observed to ensure metering and protection accuracy.

Technical Data

This section provides selection-oriented technical data for the JDZ12 series indoor/outdoor, vacuum cast voltage transformer used in 3-10 kV class AC systems (50 Hz or 60 Hz). Data shown below is intended for preliminary selection of accuracy class, rated output capacity, and insulation coordination.

Definitions: Accuracy class indicates metering precision (0.2, 0.5, 1) or protection performance (6P). Rated output (VA) is specified per accuracy class. Maximum output is the thermal overload capacity. Voltage factor defines continuous overvoltage capability (1.2 Un).

Notation: Insulation level expressed as Um / AC withstand / Lightning impulse (BIL) per IEC 61869-1 and applicable project standards.

Data Reference

Model Rated
Voltage
Ratio (V)		 Accuracy
Class 0.2
Output
(VA)		 Accuracy
Class 0.5
Output
(VA)		 Accuracy
Class 1
Output
(VA)		 Accuracy
Class 6P
Outpu
t(VA)		 Max
Output(VA)		 Insulation
Level
(kV)
JDZ12-10R 10000 / 100 / 220 15 30 60 50 500 12 / 42 / 75
JDZ12-6R 6000 / 100 / 220 15 30 60 50 500 7.2 / 32 / 60
JDZ12-3R 3000 / 100 / 220 15 30 60 50 500 3.6 / 25 / 40
Technical Note: Rated output capacity must exceed total secondary burden (connected instruments + cable losses). For accuracy class 0.2 metering applications, maintain burden at 25-100% of rated VA for optimal performance. Voltage factor 1.2 allows continuous operation at 20% overvoltage.
Application Engineering Support: Application-specific recommendations include burden calculation, accuracy assessment, secondary wiring design, and integration guidance for pad-mounted transformers and ring main units based on project specification.

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 Voltage Transformers VT-specific requirements
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: Voltage Transformers National VT requirements (aligned with IEC 61869-3)
GB 1207-2006 Voltage Transformers National VT standard for domestic projects
IEEE C57.13 Standard Requirements for Instrument Transformers Optional (North America project reference)
IEC 60068-2-17 Environmental Testing – Salt Mist Optional (project-specific environmental validation)
IEC 60085 Electrical Insulation – Thermal Evaluation Insulation thermal class reference (Class E, 75K rise)

Factory Test Compliance

  • Routine tests per applicable IEC/GB requirements (including polarity/marking verification, ratio verification, accuracy verification per specified class and burden, and dielectric withstand)
  • Dielectric tests per insulation coordination requirements and applicable standard (AC withstand and lightning impulse)
  • Visual and dimensional inspection including marking accuracy and workmanship conformity
  • Fuse coordination test where specified by project requirement
  • Type and special tests as required by project specification (temperature rise, short-circuit, partial discharge)
Compliance Note: All variants maintain full compliance with listed standards. Factory test reports provided for each manufactured unit with traceability to accredited laboratories. Fuse protection characteristics verified against transformer thermal limits.

Installation & Dimensions

  • Outline dimensions and mounting details are provided in the dimensional drawings.
  • The transformer shall be securely mounted using the designated fixing holes and bracket assembly.
  • Primary connection shall utilize sealed elbow-type cable connector matched to 200A interface specification.
  • Secondary terminals require proper sealing after wiring completion; lead seal provisions shall be utilized per utility or site requirements.
  • Adequate clearance shall be maintained for insulation, heat dissipation, and maintenance access per applicable electrical safety codes.

Outlines

JDZ12 1063 voltage transformers outline and installation 1

JDZ12-10R / JDZ12-6R / JDZ12-3R Installation Dimensions

Connection Diagrams

JDZ12 1063 voltage transformers Principle diaram 1

JDZ12-10R Typical Connection Schematic

Safety Notice: Primary voltage must be de-energized and grounded before any installation, wiring, or maintenance work. Secondary terminals must remain properly connected to burden or left open-circuit (VT secondary may be open). All work shall comply with local electrical safety regulations.

Safety Notes

  • Primary circuit must be de-energized, isolated, and reliably grounded before any work on the transformer.
  • Unlike current transformers, voltage transformer secondary circuits may be left open-circuit safely; however, proper burden connection is required for accurate operation.
  • Secondary terminal box seal shall be maintained to prevent unauthorized access and environmental ingress in outdoor applications.
  • Fuse replacement (if accessible) shall only be performed by qualified personnel with proper voltage verification.
  • All installation and maintenance work shall comply with local electrical safety regulations and utility practices.

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:

  • Model designation and voltage class (JDZ12-10R / JDZ12-6R / JDZ12-3R)
  • Rated voltage ratio (standard: 10000/100/220 V for 10kV class)
  • Accuracy requirements (metering: 0.2, 0.5, or 1 / protection: 6P as applicable)
  • Rated output capacity (VA) matched to connected burden
  • Insulation level (standard values or project-specific requirements)
  • Custom requirements (if applicable): special voltage ratios, output configurations, terminal arrangements, or environmental specifications

If local utility or project requirements apply (e.g., special voltage ratios, custom insulation levels, terminal arrangements, environmental ratings, documentation language, or required certificates), specify them at the ordering stage. Custom configurations shall be confirmed by technical agreement and final data sheet prior to production.

Customization & Engineering Support

The JDZ12 series supports flexible customization including voltage ratio variations, accuracy class combinations, output configurations, and insulation level adjustments to meet specific operating conditions and application environments. Engineering support available for:

  • Burden calculation and secondary circuit design
  • Accuracy class selection for metering and protection applications
  • Insulation coordination for high-altitude or polluted environments
  • Integration guidance for pad-mounted transformers and ring main unit applications
  • Custom voltage ratios and dual-ratio configurations

FAQs

A: JDZ12 series voltage transformers are designed for energy metering, voltage monitoring, and relay protection in 10kV, 6kV, and 3kV power distribution systems including pad-mounted transformers, ring main units, and switchgear installations.
A: Integrated internal fuse eliminates external fuse requirements, reducing installation space and complexity. Fuse characteristics are factory-matched to transformer short-circuit capacity, enhancing safety and reliability while simplifying field installation.
A: The 100V output provides voltage signals for instrumentation (meters, relays, monitoring systems), while the 220V output supplies auxiliary power for circuit breaker operation mechanisms and control circuits, eliminating need for separate auxiliary transformers.
A: Yes. Vacuum cast epoxy resin construction and sealed terminal boxes provide excellent moisture resistance. The series operates reliably in environments up to 95% daily average humidity (90% monthly average at 20°C). Outdoor installations require appropriate weatherproof enclosures.
A: Metering accuracy classes include 0.2 (revenue-grade), 0.5, and 1. Protection accuracy is 6P. Selection depends on application: use 0.2 for revenue metering, 0.5 for standard metering, 1 for indication, and 6P for relay protection circuits. Multiple accuracy classes may be specified for single transformer with appropriate burden allocation.
A: Rated output (VA) must exceed total secondary burden including all connected instruments (meters, relays, indicators), auxiliary devices, and cable losses for both 100V and 220V outputs. Maintain burden at 25-100% of rated VA for optimal accuracy class performance. Engineering support available for burden calculation.
A: Yes. JDZ12 series supports customization of voltage ratios, accuracy class combinations, output configurations, and insulation levels. High-altitude applications, special system voltages, and custom terminal arrangements can be accommodated through engineering consultation and technical agreement.
A: Maintenance requirements are minimal. Periodic external cleaning of insulator surfaces, visual inspection of terminal seals, and verification of secure mounting are recommended. Internal maintenance is not required during normal service life. Long-term stable operation with low lifecycle costs.
A: Compliance governed by IEC 61869-1/61869-3, GB/T 20840.1/20840.3, and GB 1207-2006. Factory test reports provided for each unit including routine tests, dielectric tests, accuracy verification, and fuse coordination (where applicable). All documentation traceable to accredited laboratories.
A: Installations above 2000m altitude require engineering review and may necessitate insulation level adjustments or voltage de-rating. Provide detailed altitude and environmental parameters at ordering stage for proper transformer specification and factory settings.