High Voltage Current Transformer Manufacturers – HV Metering & Protection
Subian Electric manufactures high voltage current transformers for metering and protection in substations and switchgear, from its 50,000-square-metre factory in Xuzhou, Jiangsu, China. Subian’s 350+ employees have served utilities in 50+ countries since 2019.
As a factory-direct manufacturer and supplier, Subian supplies HV CTs with correct ratios, accuracy classes and burden, factory-tested and fully documented.
Send your voltage class, ratio and accuracy requirements. Subian’s export team will respond with a quotation and technical data.
High Voltage Current Transformers Manufactured by Subian
HV current transformers for 10 kV to 35 kV class metering and protection, supplied loose or integrated into switchgear and substation packages.
What Is a High Voltage Current Transformer?
A high voltage current transformer measures circuit current at medium voltage levels, feeding proportional signals to protection relays and meters. Its insulation system must withstand the full line voltage.
HV CTs are specified for substations, switchgear and transmission monitoring – with accuracy and saturation performance that decide protection reliability.
What Buyers Check Before Ordering
- 10-35 kV class – HV CTs for substation and switchgear duty.
- Metering & protection – accuracy classes to 0.2S / 5P20.
- Factory tested – ratio, polarity and insulation verified.
- 50,000m² factory – in-house winding, casting and testing.
- 350+ employees – engineering, quality and export teams.
- OEM / ODM & wholesale – custom branding, packaging and volume supply.
Main Types of High Voltage Current Transformers
Subian supplies two HV CT types:
Metering CT
Metering
High-accuracy units for energy measurement and billing.
Class 0.5 or 0.2S / IEC 61869-2
Protection CT
Protection
Saturated-characteristic units for relay protection schemes.
5P10 or 5P20 / IEC 61869-2
High Voltage Current Transformer Specifications
| Parameter | Specification |
|---|---|
| Rated voltage | 10 kV / 35 kV class |
| Primary current | Per scheme (50 A – 2000 A) |
| Accuracy | 0.2S – 5P20 |
| Insulation | Cast resin / oil immersed |
| Frequency | 50/60 Hz |
| Standard | IEC 61869 |
How to Compare High Voltage Current Transformer Suppliers
Quotations for this equipment often look identical on the first page. The difference sits in what is attached behind the number, and in the three or four lines that decide the installed cost rather than the purchase price.
| What to compare | What a thin quotation leaves out | What to ask for |
|---|---|---|
| Application | A generic CT or PT | Metering, protection or both, and the relay it feeds |
| Burden | Ignored | Total burden including cable and relay, in VA |
| Short-circuit rating | Not stated | Rated short-time thermal current and the dynamic rating |
| Environment | Indoor assumed | Indoor or outdoor, pollution level and the creepage distance |
| Secondary terminals | A terminal box | Terminal arrangement, sealing and the shorting link |
| Calibration | A factory sheet | Calibration certificate with the traceability chain |
Buyers who compare on price alone usually discover the gap at commissioning. The six lines above are the ones that decide whether the unit or the panel can be energised without site work. OEM and ODM supply is available where the nameplate, manual and packing have to carry a different brand.
High Voltage Current Transformer Standards Buyers Ask For
The purchase specification decides the insulation level, the enclosure test and the nameplate data. These are the standards buyers normally name in the enquiry.
| Standard | What it covers | When it is asked for |
|---|---|---|
| IEC 61869-2 | Current transformers | Metering and protection cores |
| IEC 61869-3 | Voltage transformers | Inductive VT for metering and protection |
| IEC 61869-1 | General requirements | Insulation, burden and accuracy definitions |
| IEC 60044-1 | Legacy CT standard | Replacement units for older installations |
| IEC 60529 | Degrees of protection | Outdoor and polluted sites |
| GB 1208 / GB 1207 | Chinese CT and PT standards | Domestic projects and CNAS reports |
Where two standards conflict, the purchase specification wins and the conflict is recorded on the drawing before production. Type test reports are issued against the model, so ask for the report that names the rating you are buying.
HV Current Transformer Manufacturing at Subian’s 50,000 m² Factory
From winding to casting, assembly and testing – every HV CT is built and tested at Subian’s Xuzhou facility with insulation and ratio verification.
Production Workshop
Controlled winding, core processing and vacuum drying with quality checkpoints between every stage, so quality is built in from the start.
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Quality & Testing Center
Routine inspection on every unit before delivery, with type test reports supporting project approval and market certification.
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Materials & Components
Core materials, windings and components are checked against the approved bill of materials on every production run.
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OEM / ODM / Agency Supply
Custom branding, packaging and configurations for global partners – from nameplate to complete product design – supported by a dedicated export team.
Learn More →OEM/ODM & Wholesale HV CT Supply
Utilities and panel builders can brand or resell HV CTs with custom nameplates and documentation.
OEM / ODM
Factory-DirectCustom branding, packaging and product variants built on Subian’s standard platforms – from a nameplate to full product design.
Custom nameplate · Custom packaging · Full test docs
Wholesale Supply
Volume PricingFactory pricing with flexible container quantities, mixed models per container and reliable global shipping for volume buyers and importers.
Container MOQ · Mixed models · Global shipping
Distributor Support
Channel PartnersDedicated account management, technical documentation and priority production for distributors and project clients.
Account manager · Sales material · Priority lead times
Cast Resin vs Oil Immersed HV Current Transformers
Cast resin CTs are maintenance-free and suit indoor and outdoor use without oil handling. Oil-immersed units suit very high voltage classes and harsh environments.
For 10-35 kV duty, cast resin is the practical standard; Subian confirms the construction with your site.
Choosing a High Voltage Current Transformer Manufacturer
Verify accuracy class test evidence and insulation quality. CT performance directly affects protection and metering accuracy.
Subian Electric offers a 50,000m² factory, 350+ employees, ISO9001, CE and UL certification and export to 50+ countries.
Send your voltage class and ratio requirements – Subian confirms the design before production.
Certifications & Quality Assurance
Subian’s HV current transformers are produced under ISO9001, ISO14001 and ISO45001 management systems, with CE and UL certification and type test reports.
Product Certifications
10 kV Dry-Type Transformer Certificate
35 kV Transformer CB Certificate
35 kV Transformer CE Verification
Transformer CE Certificate
Dry-Type Transformer Test Verification
ISO 14001 Environmental Management
ISO 45001 Health & Safety
ISO 9001 Quality Management
110 kV Transformer Type Test Report
UL Certificate of Compliance
High Voltage Current Transformer FAQ
Answers to the questions buyers ask most about high voltage current transformers.
What is a high voltage current transformer?
What accuracy classes are available?
What is the difference between metering and protection CTs?
Can HV CTs be supplied with switchgear?
What testing is done?
What is the minimum order quantity?
Can High Voltage Current Transformer replace an existing unit?
What insulation level is used for High Voltage Current Transformer?
Contact Subian
Need the Right Specification?
Tell Subian your target market, product type, quantity and technical requirements. Subian’s team will help you identify a suitable configuration for your project.