With the advancement of energy conservation, environmental protection, and carbon comprehensive projects, the demand for Support Insulator is growing. As a professional supplier of new energy photovoltaic insulators, DUWAI/DOWE Electric Co., Ltd. will introduce the important parameters for the selection of photovoltaic insulators:

"Low voltage insulator" in a photovoltaic system， “low voltage” we usually refer to mainly refers to two types of voltage:

1. AC : Typically refers to three-phase or single-phase alternating current output from the inverter, such as 400V,480V,690V, etc.

2. DC : usually refers to the low DC voltage after a single or a small number of components are connected in series, such as the system below 1000V, which is common in distributed roof projects.

Insulators used in these voltage levels are collectively referred to as photovoltaic low voltage insulators.

Custom-engineered polymer insulators:

PBT, PET, PA66, PP and other engineering plastics. 

Customized insulators constitute the most diverse component in low-voltage cabinets：

> Rail-mounted insulators: Designed to secure conductors within the cabinet.

> Busbar clamp (JYZ insulator): For securing and supporting copper/aluminum busbars. 

> Terminal insulation sleeve: Protects terminal posts. 

> Equipment bracket: Supports miniature circuit breakers, reactors, etc. Available in various configurations, with emphasis on insulation and flame retardancy.

Because photovoltaic low-voltage insulators are used in applications closer to everyday electrical equipment, in addition to basic insulation and flame retardancy, we also need to pay more attention to safety, environmental adaptability, and long-term reliability.

1. Electrical performance

Rated voltage and power frequency withstand voltage: Ensure the Low Voltage Busbar Insulator can withstand the system's maximum voltage (AC 690V or DC 1000V/1500V) for extended periods without breakdown. For low-voltage systems, impulse withstand voltage (e.g., lightning surge resistance) is also a critical parameter.

• Creepage distance: This is a critical parameter in low-voltage environments. The minimum required creepage distance must be determined according to the pollution level of the project site (e.g., GB/T 16434 standard).

•  Calculation formula reference: Minimum creepage distance = system's maximum voltage × creepage ratio (mm/kV).

• For example: In a 400V AC system (with a maximum voltage of approximately 460V) in a moderately polluted area (with a creepage ratio of 20mm/kV), the minimum required creepage distance is 0.46kV × 20 = 9.2mm. The actual selection must be significantly larger than this calculated value.

For example, the JYZ2030 model has a creepage distance of 30mm.

2. Mechanical properties

Rated tensile/compressive/bending loads: For insulators used in support and fixation (e.g., pole insulators, busbar clamps), the maximum allowable loads including busbar electrodynamic forces, cable tension, and equipment weight must be calculated. For suspension-type insulators, the total loads such as wind loads, snow loads, and cable weight also need to be determined.

• Tear resistance and strength: Good mechanical strength prevents damage during installation, transportation or operation, especially for Low Voltage Insulator Busbar and engineering plastic parts.

For example, the DUWAI/DOWE JYZ2030 has a tensile torque of 3500N+.

3. Environmental adaptability and material properties

• Flame retardant rating (UL94): This is the core safety indicator for cabinet insulation components. Materials compliant with flame retardant standards (e.g., UL94 V-0 class) must be selected to prevent ignition during internal fault arcs.

• Temperature Index (RTI): Measures a material's long-term temperature tolerance. Insulation materials for photovoltaic equipment must have an RTI exceeding the cabinet's maximum operating temperature to prevent deformation and aging caused by prolonged heat exposure.

• Corrosion resistance: can resist salt spray, acid and alkali, humidity and other chemical erosion, which is very important for coastal, industrial areas and other special environments.

4. Long-term reliability

• Tracking resistance and electrical erosion: These are key indicators for evaluating the performance degradation of insulating materials under combined electric field and pollution effects (typically measured by the Comparative Tracking Index, CTI). Strong tracking resistance ensures the Low Voltage Insulator surface remains undamaged by creepage current.

Summary and Selection Tips

The following path can be followed when selecting insulators for photovoltaic low-voltage systems:

1. Specify the application scenario: Is it for outdoor support? For cabinet external circuit? Or for cabinet internal support and fixation? This determines the type of insulator.

2. Verify electrical parameters: Confirm the system's maximum voltage (AC/DC) and pollution level, then calculate the required creepage distance accordingly.

3. Calculate mechanical load: Calculate the static and dynamic load that the insulator needs to bear, and leave enough safety margin (usually more than 1.5 times).

4. Strict material evaluation: Focus on three core specifications: flame retardancy (UL94 V-0), anti-electrostatic discharge (CTI).

5.DOWE/DUWAI：CE,ROHS,REACH,UL test report.

In simple terms, photovoltaic low-voltage insulators shouldn 't be underestimated just because they operate at low voltages. Instead, their long-term stability and safety in complex environments require heightened attention, especially in fire prevention. Flame retardancy is an absolute non-negotiable requirement for cabinet insulation components. These insulators meet China's GB/T standards and IEC international standards, with numerous successful applications. For inquiries, please contact our technical wsh@dowechina.com!