JDZX(F)9-10 Voltage Transformer
Product Overview
The JDZX (F) 9-10 voltage transformer is a fully-enclosed, epoxy-resin cast dry-type voltage transformer designed for 10kV (Um=12kV) indoor AC power systems. It incorporates an integrated residual voltage winding (the F-type variant also functions as a discharge coil) and features excellent insulation performance, strong anti-pollution-flashover capability, and reliable operation. It is primarily used in 10kV indoor medium-voltage switchgear for voltage measurement, energy metering, relay protection, and insulation monitoring. The F-type additionally provides capacitor bank discharge functionality. The transformer is widely applied in 10kV distribution systems, prefabricated substations, ring main units, and reactive power compensation devices.
Key Product Features
Insulation and Electrical Performance
Fully-enclosed epoxy resin cast insulation: The unit is integrally formed by vacuum epoxy resin casting with no internal voids, providing excellent insulation performance. It withstands the 12kV system operating voltage and passes power-frequency and impulse withstand voltage tests. Partial discharge level is ≤10pC. Long-term operation is free from insulation aging risks, leakage, and oil contamination, making it suitable for oil-free indoor distribution applications.
Residual voltage winding design: An integrated residual voltage winding provides 100/3V output for insulation monitoring of ground faults, compatible with three-phase, five-limb voltage transformer wiring configurations to meet insulation monitoring requirements of non-effectively grounded neutral systems.
Wide voltage ratio compatibility: Supports standard voltage ratios (e.g., 10/0.1/0.1/3kV). Metering accuracy can reach Class 0.2; protection class can be customized to 3P/6P, meeting the requirements of metering, protection, and insulation monitoring applications. The F-type simultaneously satisfies the electrical parameter requirements of capacitor bank discharge coils.
High anti-pollution-flashover performance: The high-voltage side employs an integrated shed-type insulation structure with a large creepage distance, providing excellent resistance to pollution flashover in contaminated environments and reducing the risk of surface tracking.
Structural and Installation Features
Fully-enclosed dry-type construction: The integral cast structure has no exposed live parts, with a protection rating of IP20. The oil-free design eliminates fire hazards. The compact, low-profile form factor is compatible with standard switchgear installation dimensions.
Multi-function integrated design: The F-type integrates voltage transformer and discharge coil functions, simultaneously enabling voltage monitoring and residual charge dissipation from capacitor banks. This simplifies in-cabinet equipment configuration, reduces installation space, and lowers overall costs.
Clear terminal arrangement: Secondary terminals are protected by transparent covers with clear labeling, facilitating wiring and preventing misconnection and short circuits. Terminal layout conforms to in-cabinet secondary circuit wiring standards.
Flexible mounting: The base metal mounting plate is equipped with fixing holes for bolted installation, supporting horizontal in-cabinet indoor mounting. The assembly is mechanically rigid with excellent vibration resistance, enabling compact in-cabinet arrangement.
Operation and Maintenance Features
Maintenance-free operation: The dry, oil-free construction eliminates leakage and fire hazards. The high mechanical strength of the epoxy cast body provides impact and aging resistance for long-term maintenance-free operation, reducing operational costs. The F-type eliminates the need for a separate discharge coil, reducing maintenance points.
Wide operating temperature range: Designed for ambient temperatures from -30°C to +70°C. Epoxy resin properties remain stable across the full temperature range with no risk of embrittlement or deformation, suitable for varied regional climatic conditions.
High-reliability design: The iron core is constructed from high-grade silicon steel laminations, and windings are wound from enameled copper wire. Low operational losses and minimal heat generation ensure the unit withstands system switching overvoltages and lightning impulse overvoltages, guaranteeing reliable metering, protection, and insulation monitoring signals.
Technical Parameters (Typical Specifications)
Applications
Applicable voltage class: 10kV (Um=12kV) indoor AC power systems.
Typical application scenarios:
Voltage measurement, energy metering, and relay protection in indoor medium-voltage switchgear and prefabricated substations;
10kV distribution systems in distribution substations, industrial and mining enterprises, commercial buildings, and industrial parks;
Voltage monitoring, control, and protection signal acquisition in power automation systems;
Insulation monitoring in non-effectively grounded neutral systems, compatible with three-phase, five-limb wiring configurations;
F-type applicable to reactive power compensation devices for simultaneous voltage monitoring and capacitor bank discharge.
Functional purpose: Steps down high system voltage to a standard low voltage (100V) for supply to metering instruments, protection devices, and control equipment, while providing electrical isolation between the primary and secondary systems. The residual voltage winding monitors system ground faults for insulation supervision. The F-type additionally dissipates residual charge from capacitor banks to ensure maintenance safety.
Operating Conditions
Normal Operating Conditions
Altitude: ≤2000m;
Ambient temperature: -30°C to +70°C, without severe temperature fluctuations;
Relative humidity: ≤95% (non-condensing);
Environmental conditions: Free from corrosive gases, flammable or explosive media, severe vibration and shock, and significant dust or salt mist;
Installation: Indoor post-type mounting, protected from direct sunlight, rain, and condensation.
Special Operating Conditions (Customization Required)
Altitude exceeding 2000m;
Ambient temperature outside the -30°C to +70°C range;
Severely polluted, salt-mist, or chemically corrosive environments;
High-vibration or high-shock operating conditions;
Non-standard voltage ratios, accuracy classes, or installation dimensions.
Installation and Maintenance
Installation Requirements
Pre-installation inspection: Inspect the voltage transformer for external defects — the cast body must be free from cracks, voids, and damage; terminals must be clearly labeled and all accessories present. Verify that the model, rating, voltage ratio, and accuracy class match design requirements. For F-type units, confirm that discharge function parameters comply with reactive power compensation device requirements.
Mounting and fixing: Position the voltage transformer in the designated location within the switchgear cabinet and secure it through the base mounting holes with bolts, ensuring firm installation with no looseness or misalignment. The mounting surface must be level to prevent eccentric loading.
High-voltage side wiring: Connect high-voltage terminals per design requirements, ensuring tight connections and good contact. Maintain adequate safety clearance between high-voltage leads, grounded parts, and other live parts to prevent discharge. F-type units must be wired in accordance with discharge coil wiring requirements.
Low-voltage side wiring: Connect low-voltage terminals per labeling, with separate wiring for metering, protection, and residual voltage circuits. Verify correct wiring. Secondary circuits must never be short-circuited and must be reliably grounded (single-point grounding) to prevent overvoltage.
Insulation verification: After installation, measure insulation resistance (HV to LV and ground; LV to ground) to confirm compliance with insulation requirements. Verify that secondary circuit wiring is correct with no short circuits or open circuits. For F-type units, verify that the discharge function operates correctly.
Maintenance Guidelines
Periodically inspect the external condition of the voltage transformer: the cast body must be free from cracks, damage, and discharge marks; high-voltage terminals must show no looseness or oxidation; secondary terminal protective covers must be intact.
Periodically inspect high-voltage and low-voltage connections for tightness with no signs of overheating or discoloration; verify that the low-voltage circuit ground is reliable with no short circuit or open circuit risk.
Periodically test insulation resistance and voltage ratio to confirm that metering and protection accuracy meets requirements; also verify proper operation of the residual voltage circuit and insulation monitoring function. For F-type units, periodically test discharge function parameters.
Clean dust and contamination from the transformer surface; prevent oil and corrosive substances from adhering; keep the equipment dry and clean.
If cracks, discharge, overheating, voltage ratio deviation, or functional failure are detected, de-energize immediately for inspection and replace the equipment if necessary. Continued operation with known defects is strictly prohibited.
Safety Precautions
Secondary windings must never be short-circuited. A short circuit in the secondary circuit during operation will produce excessive current and endanger equipment and personnel. During maintenance, the secondary circuit must be reliably open-circuited and grounded.
During installation, avoid mechanical impact or collision with the cast body to prevent epoxy resin cracking and insulation damage, which would compromise insulation performance and anti-pollution-flashover capability.
High-voltage side wiring must use dedicated insulated leads, maintaining adequate safety clearance from grounded parts and other live parts to prevent phase-to-phase or phase-to-ground discharge. F-type unit wiring must simultaneously satisfy both voltage transformer and discharge coil wiring requirements.
Equipment grounding must be reliable; the base grounding terminal must be securely connected to the cabinet grounding busbar.
During storage, keep the unit in a dry, ventilated, cool environment, protected from direct sunlight, high temperatures, humidity, and mechanical compression to prevent aging or deformation of the cast body.
Installation, commissioning, and maintenance must be performed by qualified electrical personnel in strict accordance with electrical safety operating procedures.
Standard Supply Scope
| Parameter Category | Item | Technical Specification |
| Electrical Parameters | System Voltage | 10kV AC (Um=12kV) |
| | Rated Frequency | 50Hz | |
| | Rated Primary Voltage | 10kV | |
| | Rated Secondary Voltage | 100V (metering/protection), 100/3V (residual voltage/insulation monitoring) | |
| | Metering Accuracy Class | 0.2 / 0.5 / 1 | |
| | Protection Accuracy Class | 3P / 6P | |
| | Power-Frequency Withstand Voltage (HV terminal) | 42kV / 1min, no breakdown | |
| | Impulse Withstand Voltage (peak) | 75kV, no breakdown | |
| | Partial Discharge Level | ≤10pC | |
| | Insulation Resistance (HV to LV and ground) | ≥1000MΩ | |
| Structural and Material Parameters | Insulating Medium | Full epoxy resin cast |
| | Protection Rating | IP20 | |
| | Mounting Method | Indoor post-type bolted installation | |
| | Thermal Class of Insulation | Class B (130°C) | |
| Environmental Parameters | Operating Altitude | ≤2000m (high-altitude customization available) |
| | Operating Ambient Temperature | -30°C to +70°C | |
| | Storage Temperature | -40°C to +85°C | |
| | Relative Humidity | ≤95% (non-condensing) | |
| Applicable Standards | National Standards | GB 1207 Voltage Transformers; GB/T 20840 series; DL/T 653 Technical Conditions for Ordering Discharge Coils for Shunt Capacitors (F-type) |
Standards and Certifications
The product complies with GB 1207 Voltage Transformers, GB/T 20840.1 Instrument Transformers — Part 1: General Requirements, GB/T 20840.3 Instrument Transformers — Part 3: Additional Requirements for Inductive Voltage Transformers, and other applicable national standards. The F-type additionally complies with DL/T 653 Technical Conditions for Ordering Discharge Coils for Shunt Capacitors. The product has passed type tests and meets the operational requirements of 10kV indoor power systems.
Appendix: Product Outline Drawing
Standard Configuration
| No. | Name | Purpose |
|---|---|---|
| 1 | JDZX (F) 9-10 Voltage Transformer | Core Unit, providingVoltageTransformation / Isolation / Insulation ( F Discharge |
| 2 | Mounting Bolts / Washers | forVoltage TransformerFixed Installation |
| 3 | Secondary TerminalTransparent Protective Cover | Protection Terminal, PreventingIncorrect Connection / Short Circuit |
| 4 | Product Manual | Installation / Operation MaintenanceGuide Document, F Discharge |
| 5 | Product Certificate and Factory Test Report | Quality PerformanceCertification Document, Voltage Ratio / Error / Discharge (F )Test Data |
Order information
Before ordering, confirm applicable system voltage, metering accuracy class, protection accuracy class, mounting method, protection degree, and the required quantity according to the project drawings and source specification.
