Overview
The LZX6-35W is a 35kV / 40.5kV class outdoor high-voltage current transformer with an epoxy resin cast-resin fully enclosed dry-type structure. It is engineered for reliable operation in exposed outdoor environments, offering robust insulation performance and mechanical strength without the use of transformer oil.
Designed for both metering and protection applications, it supports accuracy classes such as 0.2S, 0.5, and 5P/10P per IEC standards. Typical installations include 35kV outdoor substations, feeder bays, industrial grid connections, and renewable energy interconnection points where oil-free, maintenance-friendly instrument transformers are required.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| Voltage class | 35kV / 40.5kV |
| Rated insulation level | 40.5/95/185kV |
| Rated frequency | 50Hz or 60Hz |
| Rated secondary current | 5A or 1A |
| Metering accuracy classes | 0.2S, 0.2, 0.5S, 0.5 |
| Protection accuracy classes | 5P, 10P |
| Installation condition | Outdoor |
| Insulation type | Epoxy resin cast-resin (dry-type) |
| Application | Current measurement, energy metering, relay protection |
| Structure type | Pillar-type, post-mounted |
| Oil-filled? | No (oil-free) |
| Design focus | Outdoor insulation, accuracy, protection reliability |
Construction
The LZX6-35W features a high-voltage outdoor dry-type epoxy resin cast-resin construction. The entire core and winding assembly is encapsulated in a solid, fully sealed epoxy body, eliminating the need for insulating oil and providing excellent resistance to moisture, UV radiation, dust, and temperature fluctuations. The pillar-type mechanical design ensures high structural rigidity for outdoor mounting on support structures or switchgear frames. Primary conductors pass through the center of the cast body, while secondary windings are embedded within the resin matrix and brought out via insulated terminal blocks. This monolithic construction delivers long-term dielectric stability, high creepage distance for outdoor pollution conditions, and immunity to leakage or fire hazards associated with liquid-filled alternatives.
Technical Parameters
Service Conditions
- Ambient temperature: -25°C to +55°C reference
- Altitude: ≤ 1000m under standard service conditions; higher altitude by agreement
- Atmospheric condition: No severe pollution, corrosive gas or explosive atmosphere beyond design limits
- Outdoor exposure: Suitable for humidity, UV exposure and tracking-resistant insulation applications
- Installation condition: No severe shock, abnormal vibration or mechanical stress beyond design limits
- Installation place: Outdoor
Technical Parameters
The LZX6-35W is an outdoor epoxy resin cast current transformer rated for 35kV / 40.5kV class systems, featuring a cast-resin insulated design suitable for ambient temperatures from -25°C to +55°C and standard altitudes up to 1000m. It complies with IEC 61869-1, IEC 61869-2, GB/T 20840.1, and GB/T 20840.2, supporting primary currents from 5A to 1250A with multiple accuracy classes and output burdens.
Single Current Ratio
| Rated Primary Current (A) |
Accuracy Classes / Rated Output (VA) | Rated Short-Time Thermal Current (kA/1s) |
Rated Dynamic Current (kA) |
|||
|---|---|---|---|---|---|---|
| 0.2S | 0.2 | 0.5S | 0.5 | |||
| 5–300 | 20 | 30 | 30 | 40 | 80 × I1n (A) | 200 × I1n (A) |
| 400 | 20 | 30 | 30 | 40 | 31.5 | 100 |
| 500 | 30 | 40 | 50 | 50 | 45 | 112.5 |
| 600 | 50 | 50 | 60 | 60 | 63 | 160 |
| 750–800 | 50 | 50 | 60 | 60 | 80 | 200 |
| 1000–1200 | 50 | 50 | 60 | 60 | 100 | 250 |
Compound Ratio or Two Secondary Windings
| Rated Primary Current (A) |
Accuracy Classes / Rated Output (VA) |
Short-Time Thermal Current (kA/1s) |
Rated Dynamic Current (kA) |
|||
|---|---|---|---|---|---|---|
| 0.2S | 0.2 | 0.5S | 0.5 | |||
| 5–300 | 10 | 15 | 20 | 20 | 80 × I1n (A) | 200 × I1n (A) |
| 400 | 20 | 30 | 30 | 30 | 31.5 | 100 |
| 500 | 20 | 30 | 30 | 40 | 45 | 112.5 |
| 600 | 20 | 30 | 30 | 40 | 63 | 160 |
| 750–800 | 30 | 40 | 40 | 50 | 80 | 200 |
| 1000–1200 | 30 | 40 | 40 | 50 | 100 | 250 |
If user’s data go beyond the above-mentioned scopes, they may be subject to an agreement between manufacturer and purchaser.
Installation & Wiring
Installation Diagram
The LZX6-35W outdoor epoxy-resin cast current transformer is designed for secure mounting on support structures using the provided hardware. Ensure proper alignment with primary conductors and maintain required clearances as specified in the installation diagram.
Wiring Diagram
Selection & FAQs
Selection Guide
- Confirm the outdoor insulation environment. Start with 40.5/95/185kV coordination, then specify altitude, pollution severity, minimum creepage, UV, tracking, condensation, temperature cycling and required outdoor test standards.
- Select a 5A–1250A single or tapped ratio. Use normal loading, future capacity and metering range; for a tapped winding, require guaranteed accuracy and output at every selected ratio.
- Choose the metering class and ratio-specific VA. Options include 0.2S, 0.2, 0.5S and 0.5 with 10VA–60VA outputs depending on single/tapped arrangement and primary current.
- Specify protection cores separately. The overview mentions 5P and 10P, but the detailed table provides no protection burden or ALF; state the full protection class, VA, secondary resistance and relay requirement.
- Verify fault and installation data. Obtain RMS short-time current with duration, peak dynamic current, primary interface, mounting loads, wind loading, terminal enclosure, grounding and the approved outdoor outline.
Frequently Asked Questions
Q1: What applications is the LZX6-35W outdoor current transformer suitable for?
It is designed for 35kV and 40.5kV outdoor power systems. The epoxy cast-resin insulation provides tracking resistance against UV and humidity. Contact us for specific project applications.
Q2: Which accuracy class should I select for revenue metering?
Select the 0.2S accuracy class for precise revenue billing. It ensures high accuracy across a wide current range per IEC 61869-2 standards. Specify your required rated output burden during ordering.
Q3: Can this 35kV current transformer operate at high altitudes?
Standard models are rated for altitudes up to 1000m. For installations above 1000m, derating or custom design adjustments are required. Please provide your exact site altitude for factory evaluation.
Q4: What international standards does this epoxy resin CT comply with?
The LZX6-35W complies with IEC 61869-1 and IEC 61869-2. It also meets the corresponding GB/T 20840.1 and GB/T 20840.2 national standards. Request the type test report for your specific project.
Q5: How is the short-circuit withstand capacity determined for this model?
The rated short-time thermal and dynamic currents depend on your selected primary current ratio, ranging from 5A to 1250A. Provide your system fault level data so we can verify the exact ratings.
Q6: Are custom primary current ratios available for this outdoor transformer?
Yes, we offer primary currents from 5A to 1250A with multiple ratio options. Standard configurations ship quickly, but custom ratios are subject to production scheduling. Confirm your exact ratio requirements with our sales team.
Q7: Why is epoxy cast-resin used for this outdoor installation?
Epoxy resin provides excellent tracking-resistant insulation against severe humidity and UV exposure. It ensures reliable operation in ambient temperatures from -25°C to +55°C. Consult our engineers if your site has corrosive gases.