IEC Standard High & Low Voltage Switchgear Selection Guide: Zhejiang Deyan Electric — Complete Power Distribution Solutions for Aging Grid Upgrade Worldwide

With the global energy transition and growing concerns over aging power infrastructure, grid upgrade has become a key focus in the power industry. Whether addressing increasing urban load density or improving power reliability in remote areas, selecting high and low voltage switchgear that complies with IEC international standards is essential. Zhejiang Deyan Electric Co., Ltd. ("Deyan Electric") is committed to providing professional complete power distribution solutions for customers worldwide, helping aging grids get a new lease on life.

Why Choose IEC Standard Switchgear for Grid Upgrade?

In the global power engineering sector, IEC standards (International Electrotechnical Commission) are the gold standard for equipment safety and compatibility. For aging grid upgrade projects, IEC compliance means:

● Safety & Reliability: Products meeting IEC 62271 (HV) and IEC 61439 (LV) standards have passed strict type tests --- including internal arc fault tests and short-time withstand current tests --- effectively ensuring personnel safety.
● International Recognition: IEC standards are widely adopted in most countries and regions worldwide, facilitating acceptance and grid connection for overseas projects.
● Environmental Adaptability: IEC standards specify clear performance requirements across different altitudes, humidity levels, and pollution degrees, making them suitable for complex on-site conditions worldwide.

Key Factors in High & Low Voltage Switchgear Selection

For aging grid retrofit projects, pay close attention to the following technical parameters and structural design:

1. Technical Parameter Matching

Rated Voltage & Insulation Level: Select switchgear with the appropriate insulation class based on the actual grid voltage (e.g., 10kV, 35kV), ensuring lightning impulse withstand voltage and power frequency withstand voltage meet requirements.

Short-Circuit Withstand Capability: Aging line upgrades typically increase system short-circuit capacity. Equipment selection must pre-calculate the prospective short-circuit current at each distribution point. The circuit breaker rated short-circuit breaking current and switchgear rated short-time withstand current (LV Icw for 1s, HV Ik for 3s) must both exceed the system short-circuit current at that point. For retrofit projects, HV incoming cabinets and LV main incoming cabinets are commonly specified at 25kA or 31.5kA.

2. Cabinet Structure & Protection

Structure Options:

● Draw-out type (truck type, e.g., KYN series): Removable circuit breaker for easy maintenance; ideal for critical load power supply.
● Fixed type (e.g., XGN series): Lower cost with simpler structure.

IP Rating: Select protection level based on the operating environment:

● Outdoor, heavy dust, or chemical/pollution environments: IP rating should not be lower than IP54.
● Standard indoor distribution rooms (no rain, no heavy dust): HV switchgear typically uses IP40; standard LV distribution panels can use IP30~IP40.
● Coastal areas with heavy salt spray or high exposure: Upgrade to IP55 or higher.

3. Core Component Configuration

Circuit Breakers: Vacuum circuit breakers (VCB) are the mainstream choice for 10kV and above systems --- offering long service life and minimal routine maintenance. For LV incoming lines, Air Circuit Breakers (ACB) are recommended; for outgoing feeders, Molded Case Circuit Breakers (MCCB).

Current Transformers: Accuracy class of 0.5 or higher is recommended to meet metering and protection requirements.

Deyan Electric: Your One-Stop Partner for Aging Grid Upgrade

Located in Yueqing, Wenzhou --- known as the "Capital of Electrical Appliances in China" --- Zhejiang Deyan Electric Co., Ltd. specializes in the R&D and manufacturing of high and low voltage complete set equipment.

Core Products & Technical Advantages

Full Product Range: Deyan Electric offers 35kV high-current GIS cabinets, 10--35kV HV switchgear, prefabricated compact substations, and LV complete set equipment --- covering the full chain from HV transmission to LV distribution.

Compact Substation Solutions: Designed for remote overseas areas or temporary urban power supply, Deyan compact substations feature modular design integrating HV incoming, transformer step-down, and LV distribution. With moisture-proof, dust-proof, and anti-corrosion properties, they are especially suitable for temporary replacement or rapid emergency repair of aging grids in harsh environments.

Adaptive Design for Overseas Projects

Deyan Electric understands the differences in power grids worldwide. Our product design balances IEC standards with local grid practices:

● Wide Temperature Range & High Altitude Design: Special adjustments to cabinet heat dissipation and insulation clearance for high-temperature Middle East projects or high-altitude South American projects.
● Smart Monitoring Interface: Supports standard communication protocols such as Modbus, enabling easy integration with SCADA systems for unmanned substation upgrades.

Conclusion

In the 2026 global power market, aging grid upgrade is more than just equipment replacement --- it is a leap forward in technical standards and operational efficiency. Choosing high and low voltage switchgear with IEC certification, high reliability, and strong environmental adaptability is the key to project success. Leveraging its geographic advantage in the Wenzhou electrical industry cluster, comprehensive product portfolio, and deep understanding of IEC standards, Zhejiang Deyan Electric is becoming a trusted partner for power engineering contractors worldwide.