Product Overview

JLSZY-35W is an outdoor three-phase three-component combined transformer for 35kV medium-voltage distribution systems. It integrates current transformer (CT) and voltage transformer (PT/VT) functions in one epoxy cast-resin assembly, providing current and voltage signals for high-voltage energy metering in 35kV networks.

This product is suitable for 35kV three-phase AC distribution networks. It is commonly used in outdoor metering points, pole-mounted metering equipment, compact substations and user-side high-voltage metering systems. The product supports active and reactive energy measurement through integrated CT and PT secondary outputs with enhanced insulation performance for 35kV applications.

Product Display

JLSZY 35W Three Phase Three Component Combined Transformer wiring diagram

JLSZY 35W Three Phase Three Component Combined Transformer product poster 01

Application Position

JLSZY-35W is installed at the medium-voltage metering point of a 35kV distribution line. The primary terminals connect to the three-phase medium-voltage circuit, while the secondary terminal box supplies voltage and current signals to active energy meters, reactive energy meters and monitoring instruments. The integrated anti-resonance device provides additional protection against ferroresonance phenomena.

Main Applications

35kV outdoor distribution networks requiring three-phase three-component metering
40.5kV class high-voltage metering systems with enhanced insulation requirements
Pole-mounted combined transformer metering boxes for 35kV applications
Outdoor metering cabinets in industrial and commercial facilities
Active and reactive energy measurement for utility revenue billing
Industrial user metering with high current requirements up to 1200A
Applications requiring anti-resonance protection in 35kV networks

Application Case Studies

Application Scenario 1: 35kV Industrial Distribution Metering
Large industrial facilities with 35kV incoming supply require accurate energy measurement for cost allocation and load monitoring. The three-phase three-component design provides complete voltage and current measurement for all three phases, ensuring balanced metering accuracy. The extended current range up to 1200A accommodates high-load industrial applications without requiring multiple metering units.

Application Scenario 2: 35kV Utility Substation Metering
Utility companies deploy combined transformers at 35kV distribution substations for revenue billing and load monitoring. The integrated anti-resonance device protects against ferroresonance phenomena common in 35kV networks with long cable runs. The enhanced insulation system with 40.5kV rated insulation level ensures reliable operation in demanding outdoor environments.

Application Fit

Suitable For

Outdoor 35kV metering points requiring three-phase three-component CT and PT signals
Utility and industrial revenue metering systems for 35kV networks
Outdoor pole-mounted metering installations in 35kV distribution systems
Compact substations and outdoor metering cabinets for 35kV applications
Medium-voltage energy metering with high primary current requirements up to 1200A
Applications requiring anti-resonance protection in 35kV networks
Projects requiring enhanced insulation performance for 40.5kV class systems

Not Recommended For

Indoor-only compact switchgear applications where indoor combined transformers are preferred
Applications requiring separate CT and PT bodies instead of integrated design
Protection-only CT applications where metering accuracy is not required
6kV or 10kV system applications (use JLSZY6 or JLSZY8 models instead)
Applications with space constraints requiring smaller footprint equipment

Installation Conditions

Installation position: Outdoor pole-mounted, outdoor metering box, compact substation or user-side metering point
Ambient temperature: -25°C to +55°C
Maximum altitude: ≤ 4500m (no derating required)
System voltage: 35kV (40.5kV maximum insulation level)
Grounding: Connect grounding terminal per local electrical codes and metering standards
Anti-resonance device: Ensure proper connection of integrated anti-resonance device in neutral circuit

Technical Parameters

The JLSZY-35W is an outdoor epoxy cast-resin combined transformer for 35kV systems with three-phase three-component design. Operating temperature -25°C to +55°C, altitude up to 4500m, compliant with GB20840.4-2015 and IEC 61869.4:2013. Features integrated anti-resonance device and extended current range up to 1200A.

Voltage Transformer Data

Rated Voltage Ratio	Rated Insulation Level (kV)	Accuracy Class / Rated Output	Max. Output
35/√3 / 0.1/√3 / 0.1/3 kV	40.5/95/200	0.2 / 3P — 3×40 VA	600 VA

Current Transformer Data

Rated Primary Current (A)	Rated Insulation Level (kV)	Accuracy Class / Rated Output	Short-Time Thermal Current	Dynamic Withstand Current
5 – 600	40.5/95/185	0.2S — 3×15 VA	80 × In	200 × In
750 – 800	40.5/95/185	0.2S — 3×15 VA	80 kA	200 kA
1000 – 1200	40.5/95/185	0.2S — 3×15 VA	80 kA	200 kA

Installation & Dimensions

Dimension Reference

JLSZY 35W Three Phase Three Component Combined Transformer installation diagram 1

Model	Key Dimensions	Approximate Weight	Application Note
JLSZY-35W	Length 1510mm; width 725mm; height 742mm	325kg	35kV three-phase three-component design

Wiring Diagram

wiring diagram

Installation Guidelines

Confirm AP1/AP2, BP1/BP2 and CP1/CP2 terminal sequence before commissioning
CT secondary circuits must not be open-circuited during operation
PT secondary terminals provide voltage input to meters and monitoring devices
CT secondary terminals provide current input to active and reactive energy meters
Grounding and meter box wiring should follow the approved project wiring diagram
Ensure anti-resonance device is properly connected in neutral circuit

Standards Compliance

Compliant with GB20840.4-2015 and IEC 61869.4:2013 for combined instrument transformers. For international projects, compliance should be aligned with applicable IEC instrument transformer standards and local utility metering rules.

Selection Guide

Select by system voltage: Use JLSZY-35W for 35kV systems (40.5kV class).

Select by current ratio: Determine CT primary current according to actual load current. Supports 5A to 1200A primary current range in three segments.

Select by metering accuracy: Use 0.2S CT accuracy for higher-accuracy energy metering.

Select by voltage ratio: Choose 35/√3 / 0.1/√3 / 0.1/3 according to network voltage and meter input requirement.

Ordering Information

When ordering, please specify:

Model: JLSZY-35W
System voltage: 35kV
PT ratio: 35/√3 / 0.1/√3 / 0.1/3 kV
CT primary current: 5A to 1200A (specify exact value)
CT secondary current: 5A or 1A
CT accuracy class: 0.2S
PT accuracy class: 0.2 or 3P
Quantity

FAQs

It is designed for outdoor high-voltage energy metering in 35kV distribution networks. The three-phase three-component design integrates CT and PT functions in one unit, providing accurate voltage and current signals for utility billing and industrial load monitoring.

In 35kV networks with long cable runs, ferroresonance can cause dangerous overvoltage conditions. The integrated anti-resonance device dampens these oscillations automatically, protecting both the transformer and connected metering equipment from damage.

The JLSZY-35W supports 5A to 1200A in three segments: 5–600A for medium loads, 750–800A for higher capacity systems, and 1000–1200A for large industrial feeders. Select the ratio based on normal operating current and anticipated load growth.

Use 40.5kV class for international specifications. This aligns with IEC standards where the maximum system voltage (Um) for a 35kV nominal system is 40.5kV. The insulation level is 40.5/95/200 kV.

The product operates from -25°C to +55°C. The epoxy cast-resin insulation maintains its properties throughout this range, making it suitable for extreme cold regions and hot climates without performance degradation.

Yes, the JLSZY-35W is rated for altitudes up to 4500m without derating. The epoxy cast-resin insulation does not depend on air for insulation or cooling, so it maintains full performance at high altitudes.

CT accuracy class is 0.2S for revenue metering. PT accuracy classes of 0.2 (precision metering) or 3P (protection and monitoring) are available. The rated output for CT cores is 3×15 VA.

Please specify: system voltage, PT ratio, CT primary current (5–1200A), CT secondary current (5A or 1A), CT accuracy class, PT accuracy class, rated burden, installation type, and quantity.

JLSZY-35W Three-Phase 35kV Three-Component Combined Transformer