Overview
The JLSZV-24W is an outdoor epoxy resin cast three-phase two-component combined transformer rated for 24kV medium-voltage distribution systems. It integrates current transformer (CT) and voltage transformer (PT) functions into a single cast-resin assembly, providing accurate current and voltage signals for metering and protection.
This 24kV combined transformer features high precision classes (0.2S, 0.2, 0.5), making it suitable for revenue-grade metering in industrial substations, outdoor pole-mounted installations, and utility distribution networks. It complies with GB20840.4-2015 and IEC 61869.4 standards and offers 24/65/125kV class insulation for reliable outdoor performance.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| System Voltage | 24kV |
| Insulation Level | 24/65/125kV |
| Primary Current Range | 5A – 2000A |
| Secondary Current | 1A or 5A |
| Secondary Voltage | 100V or 100/√3 V |
| Metering Accuracy (CT) | 0.2S, 0.2, 0.5 |
| Protection Accuracy (CT) | 5P10, 5P20 |
| PT Accuracy Class | 0.2, 0.5 |
| Frequency | 50Hz / 60Hz |
| Creepage Distance | ≥25mm/kV |
| Lightning Impulse Withstand | 125kV (peak) |
| Ambient Temperature Range | -25°C to +55°C |
Construction
The JLSZV-24W features a monolithic epoxy cast-resin construction that fully encapsulates the magnetic cores and windings, eliminating the risk of oil leakage and ensuring maintenance-free operation. The housing is UV-resistant and formulated for long-term outdoor exposure, with high creepage distances on external surfaces to prevent flashover in polluted or humid environments. Primary terminals are made of tinned copper for low contact resistance and corrosion resistance, while secondary connections are housed in a sealed, tamper-proof terminal box with IP54 protection. The design incorporates reinforced insulation barriers between phases and ground, meeting stringent impulse and power frequency withstand requirements per IEC 61869.4.
Technical Parameters
Service Conditions
- Installation position: Outdoor substations, pole-mounted, or distribution points
- Ambient temperature: -25°C to +55°C
- Maximum altitude: ≤ 2000m
- Environment: Outdoor with weather exposure
- Grounding: Connect grounding terminal per local electrical codes and metering standards
- Maintenance: Epoxy resin construction requires minimal maintenance in outdoor environments
Technical Parameters
The JLSZV-24W is an outdoor epoxy cast-resin combined transformer for 24kV systems, featuring a three-phase two-component design. It operates within a temperature range of -25°C to +55°C at altitudes up to 2000m, complies with GB20840.4-2015 and IEC 61869.4:2013, and supports a wide primary current range from 5A to 2000A.
Voltage Transformer Data
| Rated Voltage (kV) |
Rated Insulation Level (kV) |
Accuracy Class / Rated Output |
Max Output (VA) |
|---|---|---|---|
| 20/0.1 | 24/65/125 | 0.2 (2×30VA), 0.5 (2×100VA) | 600 |
Current Transformer Data
| Rated Primary Current (A) |
Rated Insulation Level (kV) |
Accuracy Class / Rated Output |
Short-Time Thermal Current |
Dynamic Current |
|---|---|---|---|---|
| 5 – 600 | 24/65/125 | 0.2S (2×30VA) | 80 × In | 200 × In |
| 750 – 800 | 24/65/125 | 0.2S (2×40VA) | 80 kA | 200 kA |
| 1000 – 2000 | 24/65/125 | 0.2S (2×40VA) | 100 kA | 250 kA |
Installation & Wiring
Installation Diagram
The JLSZV-24W is designed for outdoor pole or platform mounting. Ensure the unit is securely fastened to a stable base with adequate clearance around all sides for safety and maintenance access. Follow local regulations for clearances and grounding practices.
Wiring Diagram
The wiring diagram shows connections for both current transformers (CT) and voltage transformers (PT). Terminals AP1/AP2 and CP1/CP2 correspond to the primary bushings visible in the front view. CT secondary terminals supply current signals to energy meters and protection relays, while PT secondary terminals provide voltage inputs for metering and protective devices. Always verify terminal sequence and polarity before commissioning.
Selection & FAQs
Selection Guide
- Select for 24kV systems with a 24/65/125kV insulation level.
- Choose CT primary current based on actual load, within the 5A to 2000A range (available in three segments: 5-600A, 750-800A, and 1000-2000A).
- Specify CT accuracy class as 0.2S for high-accuracy energy metering applications.
- Select PT accuracy class as either 0.2 or 0.5, depending on metering requirements.
- Confirm PT voltage ratio as 20/0.1kV to match network voltage and meter input specifications.
Frequently Asked Questions
Q1: How does extreme temperature affect this 24kV combined transformer?
It operates reliably in ambient temperatures from -25°C to +55°C. The epoxy cast-resin construction ensures minimal maintenance and weather resistance. Confirm specific site conditions with our engineering team.
Q2: Which voltage transformer accuracy class suits revenue metering?
Select the 0.2 accuracy class (2×30VA) for precise revenue billing applications. The 0.5 class is available for general measurement. Specify your exact metering requirements during order placement.
Q3: Can this outdoor transformer be installed at high altitudes?
Yes, it is designed for maximum altitudes up to 2000m. For installations exceeding this limit, derating or special design modifications are required. Contact us for high-altitude project evaluation.
Q4: What international standards does this cast-resin transformer comply with?
The JLSZV-24W complies with IEC 61869.4:2013 and GB20840.4-2015 standards. Factory test reports are provided upon request. Please specify your required compliance documentation during the inquiry stage.
Q5: Can the primary current rating be customized up to 2000A?
Yes, the current transformer supports a wide primary current range from 5A to 2000A. Custom ratios are subject to factory confirmation. Provide your exact primary and secondary current requirements for a quote.
Q6: Where is this 24kV combined instrument transformer typically applied?
It is primarily used in outdoor substations, pole-mounted setups, and distribution points. The cast-resin design provides excellent protection against outdoor weather exposure. Verify installation suitability with your project engineer.