The high voltage switchgear is faced with a serious problem, the electrical breakdown and flashover under high voltage cause equipment failure and safety accidents. Poor flame retardancy causes fire in short circuit or overheat, threatening equipment and personnel safety. The insulation performance deteriorates and deformation occurs in high temperature/humid environment. Not sufficient mechanical strength, breaking during installation/operation, affecting stability. These problems are solved by FR4 Fiberglass Rod and it becomes the preferred High voltage insulation rod for switchgear. Below is an introduction to the AHD – FR4 Rod.
FR4 Epoxy Glass Rod Electrical Insulation Performance
1. Ultra-High Dielectric Strength to Prevent Electrical Failure
High dielectric strength FR4 rod for switchgear has a dielectric strength of 20–25 kV/mm, which is much higher than the industry standard of 10–15 kV/mm for high-voltage switchgear insulation. A short term high voltage of 60-75 kV can be tolerated by a 3 mm diameter FR4 rod to avoid electrical breakdown. It has stable insulation performance even under humid conditions, and volume resistivity ≥10¹³ Ω·m. This performance is aimed directly at FR4 insulation rod electrical failure prevention requirements, ensuring switchgear safety.
2. High stability insulation resistance in harsh environments
Low moisture absorption FR4 insulation rod, the water absorption rate is ≤0.1%, much lower than 3240 epoxy rod (0.2%-0.5%). To avoid degradation of performance, its insulation resistance is ≥10¹¹ Ω after 1000 hours at 85°C/85% RH. Stability is suitable for coastal/high humid substations.
UL94 V-0 Flameretardancy Critical Safety Switchgear
UL94 V-0 Certification - The Highest Flame Retardant Grade
UL94 V-0 insulation rod for the toughest UL94 V-0 standard. The way the flame is applied the flame itself puts it out in 10 seconds with no burning droplets that can ignite surrounding material. In short-circuit/overheating situations it prevents fire spread, protecting equipment and personnel. All AHD flame retardant FR4 rod for electrical insulation meet this standard, certified by authoritative institutions.
Thermal stability for operation at high temperatures
FR4 rod high temperature resistance switchgear is thermal class F (155°C), and some modified grades can reach H (180°C). It withstands thermal shock (10 cycles without cracking) and operates at temperatures between -40°C and 120°C. This stability prevents deformation/brittleness in high-temperature switchgear, ensuring long-term reliability.
Improved Mechanical Properties for Structural Support in Switchgear
High mechanical strength for stability of installation
FR4 epoxy glass rod has a flexural strength of 300-450 MPa and a compressive strength of ≥500 MPa, comparable to metal. It resists bending/breaking during installation/operation . Holds busbars and components in switchgear . AHD has a wide range of options of FR4 epoxy rod from 6mm-130mm diameter for different load needs.
Light weight and customizable processability
FR4 rods reduce equipment weight and installation difficulty with a density ~2.0 g/cm³ . They are easy to cut, drill and machine. Custom FR4 fiberglass rod for switchgear parts. “32 years of experience with AHD provides tailor-made solutions for unique switchgear designs.
FR4 vs. Traditional Insulation Materials
| Dielectric Strength (kV/mm) | Flame Retardancy | Water Absorption | Mechanical Strength | Cost | |
| FR4 | 20–25 | UL94 V-0 | ≤0.1% | High (300–450 MPa) | Moderate |
| 3240 Epoxy | 10-15 | Non-V0 | 0.2%–0.5% | Medium (250 MPa) | Low |
| Ceramic |
10-20
|
V-0 | ≤0.05% | High (Brittle) | High |
| PTFE | 20-30 | V-0 | ≤0.01% | Low (50–70 MPa) | Very High |
FR4 is a compromise between function and cost, better than 3240 for insulation/flame retardance and ceramics/PTFE for processability/cost.
Adherence to Industry Standards for Switchgear
The insulating materials of switchgear shall meet the requirements of GB/T 11022, IEC 62271 and UL94 V-0.
FR4 meets all requirements: dielectric strength ≥15 kV/mm, CTI ≥300 V, water absorption ≤0.3% and flame retardancy V0. AHD’s FR4 rods are rigorously tested to achieve 99.8% performance compliance.
The FR4 insulation rod for high voltage switchgear has excellent electrical insulation (20~25 kV/mm dielectric strength), UL94 V-0 flame retardancy, high mechanical strength (300~450 MPa) and low moisture absorption (≤0.1%). It solves the fundamental switchgear problems: electrical breakdown, fire hazards, hostile environment instability and mechanical failure. A trusted supplier of AHD plastic Sheet and Rod with 32 years of expertise, full compliance, and custom solutions. High-quality FR4 rods.
AHD Benefits: Trustworthy FR4 Insulation Rod Manufacturer
32 Years Experience & Full Product Line
1. Switchgear professional FR4 insulation rod supplier
AHD has 32 years of engineering plastic manufacturing experience. We stock a complete range of engineering plastic sheets and rods including FR4. We stock 6mm-130mm diameter FR4 epoxy rods.
2. Custom Services & Quality Assurance
All AHD FR4 rods passed the strict electrical, mechanical and flame retardancy tests, with the performance compliance rate ≥99.8%. We have a large stock, so we can fast deliver the custom FR4 fiberglass rod for switchgear parts (size, shape, performance). Pick AHD for factory direct prices, trusted quality and dedicated service.
Contact AHD today for samples, trial orders, professional selection advice and detailed performance test reports. Our experts are here to help you find the perfect FR4 insulation rod solution for your needs!
Q1. What is the difference between FR4 and 3240 epoxy rods for switchgear?
A1: FR4 is more suitable for high-voltage switchgear due to its superior dielectric strength (20-25 vs. 10-15 kV/mm), UL94 V-0 flame retardancy (3240 non-V0), lower water absorption (≤0.1% vs. 0.2-0.5%), and better high-temperature resistance (155°C vs. 130°C).
Q2:How to select the correct diameter of FR4 rods for switchgear applications?
A2: Take into account the voltage level, mechanical load and the available installation space. AHD has FR4 epoxy rod from 6mm to 130mm diameter. Larger diameters are needed for higher voltages/loads.
Q3: Can I use FR4 insulation rods in outdoor high voltage switch gear?
A3: Yes. FR4’s low moisture absorption (≤0.1%) and steady performance in -40°C to 120°C make it ideal for outdoor applications. AHD outdoor grade FR4 rods provide enhanced UV resistance for stable insulation in coastal/high-humid conditions.
