In the fields of new energy, energy storage, EV charging stations, and industrial control, Isolation Switches are critical components for system safety. They are primarily used to reliably disconnect circuits from the power supply during maintenance or emergencies, thereby protecting equipment and personnel. Especially in high-voltage DC applications—such as 1500 VDC photovoltaic systems, energy storage battery packs, and DC fast chargers—the performance, UL certification, and reliability of Isolation Switches are of paramount importance.
This article presents the top 10 UL-certified Isolation Switch manufacturers in China and compares them with several internationally recognized brands, helping global buyers and system integrators quickly understand the market landscape.
Why Isolation Switches Matter & Why UL Certification is Key
Purpose of Isolation Switches
In DC systems (e.g., PV modules → combiner box → inverter, energy storage systems, EV systems), even after a controller disconnects, power may still be present. For maintenance or inspection, it is necessary to cut off the power circuit. A “visually disconnectable” or manually operable OFF-position Isolation Switch is required to ensure safety.
Compared with circuit breakers—which usually provide overload/short-circuit protection—Isolation Switches primarily serve the functions of physical disconnection and visible separation.
For high-voltage DC systems, stricter requirements exist for arc extinguishing, voltage withstand, contact spacing, air gap dielectric strength, and enclosure protection.
Why UL Certification Matters
UL (Underwriters Laboratories) is an independent global safety science company providing product testing and certification services. UL certification, especially UL 508 and UL 98 standards for Isolation Switches, ensures that products meet international standards for electrical isolation, voltage withstand, and durability.
For DC systems such as solar inverters or battery energy storage systems, UL certification reduces the risk of fire and electric shock and improves competitiveness in North American and global markets. According to UL official data, over 90% of North American buyers prioritize UL-certified products, highlighting its market value. For manufacturers, UL certification enhances overseas customer trust, shortens approval cycles, and reduces compliance risks.
Top 10 UL-Certified Isolation Switch Manufacturers in China
Zhejiang HIITIO New Energy Co., Ltd.
Official Website: https://www.hiitio.com/
UL-Certified Products: The HCG4L series DC Isolation Switches are UL98A and IEC60947-3 certified, with rated voltages up to 1500 VDC and current ratings from 250 A to 1600 A. Widely applied in PV inverters, energy storage systems (ESS), and EV charging cabinets.
Core Technology: HIITIO uses proprietary magnetic blowout arc-extinguishing technology, allowing fast and safe circuit disconnection under 1500 V DC, extending contact lifespan and reducing energy loss. Silver alloy contacts and ceramic insulating supports ensure high conductivity and excellent thermal stability. The modular design supports front/back panel mounting, rotary handles, and remote linkage operation, meeting diverse integrator requirements.
HIITIO DC Isolated Switch Real Cases
Market Position: A leading innovator in high-voltage DC equipment, HIITIO’s Isolation Switches serve North American energy storage projects, European PV inverter manufacturers, and Middle Eastern EV fast-charging facilities. With a mature OEM/ODM system, custom projects can be delivered within 2–4 weeks.
Unique Selling Points (USP):
- UL certification + patented magnetic blowout technology
- Structure optimized for energy storage and high-voltage DC applications
- Fast delivery and flexible OEM/ODM customization
- Full series compliance with IEC60947-3 and UL508i standards
CHINT Group Co., Ltd.
Official Website: https://chint.co.uk/
UL-Certified Products: CHINT’s NZ7 series DC Isolation Switches represent a new generation of UL-certified solar protection devices built for reliability and modular flexibility. Certified under UL 508, the NZ7 series is engineered to handle voltages up to 1500 V DC with a breaking capacity of 10 kA, ensuring stable performance even under extreme load fluctuations.
Core Technology: Leading low-voltage electrical manufacturer, NZ7 series UL 508 certified, rated voltage 1500 V DC, breaking capacity up to 10 kA. Modular design with remote monitoring, suitable for solar power plants and EV charging stations.
Market Position: Overseas revenue accounts for 30% (2022). UL-certified products have steadily gained North American market share, supplying over 100 large-scale PV projects globally.
Delixi Electric Co., Ltd.
Official Website: https://www.delixi-electric.com/en
UL-Certified Products: Delixi’s CDW9 series DC Isolation Switches are built to meet the demanding requirements of high-voltage DC power systems. Certified under UL 98, the CDW9 series operates at 1000 V DC and provides high segmentation performance to ensure rapid isolation during maintenance or fault conditions.
Core Technology: UL 98 certified, designed for high-voltage DC systems, rated voltage 1000 V DC, high segmentation, low power loss, silver alloy contacts, 20,000 operation cycles.
Market Position: Exported to over 50 countries, with ~15% market share in industrial automation; widely used in energy storage systems.
People Electrical Appliance Group Co., Ltd.
Official Website: https://www.peopleelectric.com/
UL-Certified Products: The RDM1 series DC Isolation Switches from People Electric are designed to deliver robust protection in DC microgrids and renewable energy applications. Holding UL 508 certification, these switches support up to 1200 V DC with a breaking capacity of 6 kA. The double-insulated structure enhances operator safety, while flame-retardant housings and RoHS compliance ensure environmental and operational reliability.
Core Technology: UL 508 certified, 1200 V DC, 6 kA breaking capacity, double insulation, RoHS compliant, suitable for harsh DC microgrid environments.
Market Position: Strong presence in Southeast Asia and the Middle East; exports grew 20% YoY in 2023.
Simon Electric Co., Ltd
Official Website: https://www.simonelectric.com/intl
UL-Certified Products: Simon Electric’s SDC series DC Isolation Switches combine European design expertise with Chinese manufacturing precision. Certified under UL 98, these switches are rated for 800 V DC with a breaking capacity of 4 kA, optimized for residential and commercial photovoltaic installations. The compact, spring-assisted disconnection mechanism enables fast, reliable operation while minimizing mechanical wear.
Core Technology: UL 98 certified, 800 V DC, 4 kA breaking capacity, compact design, spring-assisted mechanism for faster disconnection.
Market Position: China-Spain joint venture; widely used in residential and commercial PV systems.
Huawei Digital Power Technologies Co., Ltd.
Official Website: https://digitalpower.huawei.com/en
UL-Certified Products: FusionSolar Isolation Switches
Core Technology: UL 1741 certified for solar inverter integrated switches, rated voltage 1500 V DC, supports smart grid protocols, SiC technology, AI-enabled predictive maintenance.
UL-Certified Products: JHD series DC Isolation Switches
Core Technology: UL 508 certified, 1000 V DC, high insulation resistance, vibration resistant, military-grade materials, integrated fiber optic sensors for arc detection.
Market Position: State-owned enterprise, UL-certified products used in Belt and Road projects.
AVIC Jonhon Optronic Technology Co., Ltd.
Official Website: https://www.jonhon-ev.com
UL-Certified Products: JHD series DC Isolation Switches
Core Technology: UL 508 certified, 1000 V DC, high insulation resistance, vibration resistant, military-grade materials, integrated fiber optic sensors for arc detection.
Market Position: State-owned enterprise, UL-certified products used in Belt and Road projects.
Gree Electric Appliances, Inc. of Zhuhai
Official Website: https://global.gree.com
UL-Certified Products: GREE series DC Isolation Switches
Core Technology: UL 508 certified, 600 V DC, copper-silver composite contacts, self-cooling, 15,000 operation cycles, optimized heat dissipation.
Market Position: Known for home appliances, rapidly growing electrical components business, exports UL-certified products to North America.
Great Wall Electric Co., Ltd.
Official Website: https://www.gwpst.com
UL-Certified Products: GW series DC Isolation Switches
Core Technology: UL 98 certified, 1000 V DC, 5 kA breaking capacity, high cost-performance, fully enclosed structure, IP65 protection.
Market Position: Representative mid-sized Chinese enterprise, popular in developing country markets.
LONGi Green Energy Technology Co., Ltd.
Official Website: https://www.longi.com/us
UL-certified Products: LONGi series DC isolators (UL98B)
Core Technology: High-efficiency photovoltaic modules
Applications: Large-scale solar power plants
Market Position: World’s largest manufacturer of monocrystalline silicon products
Comparison: Chinese Manufacturers vs. International Brands
| Dimension | Chinese Manufacturers (HIITIO, CHINT) | International Brands (ABB, Eaton) |
| Cost | Significant cost advantage, ~30–50% lower | Higher cost, comprehensive after-sales service |
| Technology Maturity | High-voltage DC disconnection technology rapidly improving | Long-term engineering experience |
| Certification Coverage | UL, IEC complete | UL, CSA, IEC full certification |
| Customization | Strong, fast response | Low flexibility, long lead time |
| Delivery Speed | Fast (2–4 weeks) | Slower (6–8 weeks) |
EXPLORE MORE HIITIO ISOLATION SWITCH
Conclusion
With the growth of DC systems, rising voltage levels in PV/energy storage systems, and rapid expansion of EV charging, Isolation Switches are no longer just simple ON/OFF components—they carry critical safety, maintenance, and compliance responsibilities. For projects require UL certification and complex system design, choosing the right UL-certified Chinese manufacturer is essential.
With strong R&D capabilities and international certification experience, HIITIO is becoming the preferred Chinese manufacturer for North American energy storage and European PV markets, competing effectively with international brands in safety, reliability, and delivery flexibility.
