Selecting the current transformer ratio in high-voltage switchgear depends on transformer capacity. Calculate the rated current using Ie = S / (√3 × U). For a 1600 kVA, 10 kV transformer, the rated cu

The operation process for epoxy resin dynamic mixing equipment includes weighing resin, curing agent, color paste, and silica filler; adding materials in sequence; pouring into the mixing tank with pr

On October 17, 2026, the Luxi Electric Porcelain Industry Overseas Trade Matchmaking Conference was held at the 140th Canton Fair. CNYIHU, a professional manufacturer of instrument transformers and va

A Russian delegation visited CNYIHU for factory acceptance of transformer foil winding and coil winding machines. The technical, project, and commercial teams accompanied the inspection. Tests include

CNYIHU delivered a complete winding production line to a Zhejiang instrument transformer factory for capacity expansion. The line includes 3 CT winding machines, 7 automatic VT primary winding machine

To perform a power frequency withstand test on a fully insulated voltage transformer, connect the console's red wires to the step-up transformer input, blue to the return instrument, and black to grou

Vacuum circuit breakers use vacuum as the arc-quenching and insulating medium. When contacts separate, an arc forms, but at current zero the metal vapor condenses, charged particles decrease, and the

Daily maintenance of instrument transformer winding machines includes pre-start checks, cleaning copper debris, proper lubrication, daily inspection of wearing parts, and shutdown protection. These st

Chairman Zhang Shaoming conducted a routine factory inspection at CNYIHU, checking automated equipment, work-in-progress, 5S management, and quality control for instrument transformer and power equipm

The High-Voltage Electrical Industry Annual Meeting hosted by the China Electrical Equipment Industry Association (CHVS) brought together experts, research institutes, and equipment manufacturers to d

Surface bubbles and rough surfaces in instrument transformer casting can result from six main causes: improper mold venting, insufficient vacuum in the resin mixture, uneven release agent, abnormal ra

A dynamic mixing tank is essential in epoxy resin casting and APG lines. For continuous operation, it can run for a week without full cleaning; simply discharge mixed resin and hang the feed pipe to p

Epoxy resin instrument transformer cracking has five common causes: stress concentration from sharp metal edges, batch cracking from rapid heating or cooling without stepped curing, interface delamina

APG vs Vacuum Casting Resin for Instrument TransformersAPG resin and vacuum casting resin are not the same and cannot be directly interchanged. They differ in formulation, process, and performance....

The LZZBJ9-35 is a 35kV indoor dry-type current transformer with one-piece epoxy resin casting. Its multi-skirt design provides sufficient creepage distance, anti-condensation, and pollution resistanc

Voltage transformers are classified by insulation into dry-type, cast-resin, oil-immersed, and gas-insulated types. Cast-resin is suitable for 35kV and below, while above 35kV is generally oil-immerse

A Vietnamese customer delegation visited CNYIHU for factory acceptance of epoxy resin vacuum casting equipment and multiple dedicated winding machines. They also discussed long-term cooperation on ins

CNYIHU has commissioned the YB-300CL toroidal coil insulation taping machine for current transformers. It wraps polyester film, high-temperature tape, and crepe paper around toroidal windings, serving

Comprehensive guide to surge arrester types including 10kV station, distribution, thermal-explosion, drop-out, and intermittent designs for overhead line protection. Also covers 24kV, 35kV, and 66kV

CNYIHU secured an order for 20 automatic paper-feeding primary coil winding machines from a long-term Liaoning customer. These machines improve voltage transformer primary winding efficiency and reduc

Partial discharge testing is critical for instrument transformer reliability. Internal voids and cracks cause gradual insulation degradation over months or years, forming carbonization channels that l

The solid‑core pole of a primary‑secondary fusion circuit breaker houses a vacuum interrupter, electronic current transformer, voltage sensors, capacitive power supply, shielding mesh, and conductive

A circuit breaker (CB) controls and protects power systems by interrupting normal and fault currents, while a disconnector switch (DS) only isolates circuits for maintenance and cannot break load curr

CNYIHU has completed two custom‑built transformer winding machines that wind two coils simultaneously with multi‑function pay‑off stands. The modular design supports various transformer sizes and redu

When CT secondary is open, I₂=0, demagnetization lost. Primary flux saturates core, inducing high voltage that can break insulation, endangering safety, causing metering errors and relay misoperation.

Municipal Metrology Bureau leaders visited our company to inspect innovation-driven development. They toured production workshops, R&D center, and showroom, examining automated lines, quality control,

A delegation of Korean project and technical leads visited Yihu Electric for a business inspection and technical exchange. They toured production workshops, evaluated transformer manufacturing capabil

Composite insulatorcrimping machineCrimping Type: QHYJ-165/6000kNⅠ.summary1. This equipment is primarily designed for the crimping operation of metal fittings and core rods in composite insulator p...

Inspect the toroidal core for excitation characteristics, dimensions, winding tightness, and ensure no burrs, sharp edges, or rust on the surface. Wrap multiple layers of crepe paper and semi-conducti

Inspect the R-shaped core for excitation performance, dimensions, tight winding, and absence of burrs, sharp edges, or rust. Wrap multiple layers of crepe paper, semiconductive insulating tape, and DM

The solidified pole unit is a core component of vacuum circuit breakers, its installation quality directly affects loop resistance, phase imbalance, and the service life of the arc extinguishing ch...

The ZN85-40.5 indoor drawer-type vacuum circuit breaker is compatible with the KYN61-40.5 indoor switch cabinet. It consists of an insulating cylinder, operating mechanism, trolley advancing mechan...

A 10kV manual outdoor high-voltage vacuum circuit breaker with isolation consists mainly of four parts: Disconnector: It provides a clearly visible disconnection point on the line, facilitating ma...

Loose enamel wire during winding with a voltage transformer primary winding machine is usually caused by insufficient tension. Simply increase the tension value on the tensioner to fix this issue.

Voltage transformer primary winding machines count turns based on a gear ring fixed to the epoxy frame. The number of teeth on the gear ring varies depending on the diameter of the frame. If the to...

First, thoroughly clean the mold cavity of dust and residual resin. Spray a high-temperature-resistant dedicated APG release agent (the mold temperature should be maintained at approximately 60°C; ...

The principle of a current transformer winding machine involves first storing enamel wire in a storage slot before reversing it onto a toroidal core. By inputting the core’s inner diameter, outer d...

Congratulations to Yihu Electric for winning the bid in State Grid Corporation of China’s 2024 eighth batch procurement for 10kV metering composite current transformers and 10–35kV metering current...

a. Safe Operation: Strictly follow safety procedures during installation and operation to ensure personnel safety. Avoid using sharp objects that may scratch the insulator surface. b. Proper Insta...

Two models of composite current transformers—JZZY1-10 and JZZV1-10—developed by Yihu Electric have successfully passed State Grid's full-performance testing and are now ready for mass production.

To continuously improve epoxy molding technology and enhance the insulation reliability of CT/PT and sealed pole terminal from the source, Yihu Electric has recently completed an upgrade and offici...

Dry-type epoxy transformers are primarily molded using either vacuum casting or APG (Automated Pressure Gelation) processes. Both methods can produce qualified CTs and PTs, but differ significantly...

In power distribution systems, lightning surges and switching overvoltages constantly threaten the insulation of equipment such as voltage transformers, transformers, and switch cabinet. Arresters ...

Vacuum circuit breakers rely on vacuum as the arc-quenching medium and are primarily used in 10kV to 40.5kV distribution systems. They are widely integrated into switch cabinet and often used in co...

Several independently developed technologies by the company—including transformer structural design, automated winding processes, and insulation components—have successfully passed rigorous review ...

Recently, after through equipment debugging, process optimization, small-batch trial production, and stability testing, our fully automatic voltage transformer primary winding machine has met all p...

Yihu Electric holds 2026 Annual Technical Solutions Conference, bringing together key executives, and the core members of R&D center, process engineering, production, sales teams, quality departmen...

CNYIHU Electric Held 2026 Annual Instrument Transformer Technology Solutions ConferenceFocusing on New‑Type Power Systems, Empowering Smart Grids WorldwideOn July 28, 2026, NHE International Limite...

Release Date: July 24, 2026 | Source: China Business Network On July 24, the National Energy Administration held the second national energy supervision work conference of 2026

Release Date: May 8, 2026 | Source: National Energy Administration The 500,000 kW photovoltaic power station supporting Datang Zhongwei Cloud Base was successfully connected to the grid. It is China’

Release Date: July 24, 2026 | Source: Xinhua News Agency On July 24, State Grid released its construction and operational data for the first half of 2026. Fixed-asset investment reached 312.6 billion

Release Date: July 27, 2026 | Source: CCTV News, National Energy Administration On July 27, the final section of wire erection was finished for the Yantai-Weihai 1,000 kV UHV Project in Shandong, mar