With the demand for energy-efficient and compact power infra beginning to take root, the significance of the trustworthy high voltage insulation components has increased more than ever before. One such vital component is the polymer wall bushing, which has a critical role in electrical safety and system stability at substations, switchgear cabinets, and transformers.
At Hewei, we have as the main focus the provision of the electrical insulation solutions and gadgets and are the leaders in this field of operation, we thus, are proud to have come up with a varied selection of high-performance both polymer, and porcelain, bushings which are compliant with the newly released industry standards that our audience can make their choices and wish that the quality they get wins their preference over any other. This article would help you to choose the right polymer wall bushing, as well as to compare it with the old technology, such as a condenser porcelain bushing.

What Is a Polymer Wall Bushing?
A polymer wall bushing is an insulating device that allows an electrical conductor to pass safely through a grounded barrier, such as the wall of a transformer or switchgear enclosure. Its key functions include:
- Providing electrical insulation
- Offering mechanical support
- Withstanding electrical stress, particularly in high-voltage systems
Made of silicone rubber or epoxy resin, polymer bushings are lightweight, weather-resistant, and more resilient against pollution compared to their porcelain counterparts.
Key Factors to Consider When Choosing a Polymer Wall Bushing
1. Rated Voltage and Full Wave Impulse Withstand Voltage
One of the first criteria to consider is the full wave impulse withstand voltage (FWIWV)—a measure of the bushing’s ability to endure sudden high-voltage surges such as lightning or switching impulses. For example:
- A 35kV bushing should withstand impulse voltages of 200kV or more
- Ensure the bushing matches both the rated voltage and impulse strength requirements of your system
Hewei‘s polymer wall bushings are tested under IEC and ANSI standards to guarantee robust impulse resistance.
2. Current Carrying Capacity
The conductor inside the bushing must be capable of handling the expected load current without overheating. This involves evaluating:
- Cross-sectional area of the conductor
- Type of conductor connection (copper or aluminum)
- Cooling environment (air or oil)
3. Environmental Conditions
Polymer wall bushings are especially suitable for harsh environments due to their:
- High hydrophobicity
- Pollution resistance
- Lighter weight for easier installation
If your project is in coastal, dusty, or high-altitude regions, polymer wall bushings are preferred over condenser porcelain bushings, which are heavier and more brittle.
Polymer vs. Condenser Porcelain Bushing
Feature | Polymer Wall Bushing | Condenser Porcelain Bushing |
---|---|---|
Weight | Lightweight | Heavy |
Pollution Resistance | High | Medium |
Mechanical Strength | High | Fragile under impact |
Installation | Easy | Requires careful handling |
Cost | Slightly higher initial cost | Lower initial cost but higher maintenance |
While condenser porcelain bushings are still used in legacy systems, modern grids and compact substations increasingly prefer polymer wall bushings for their ease of handling and long-term durability.
Customization and Standards
で Hewei, we offer customized polymer bushings to match unique design requirements, including:
- Flange size and mounting interface
- Creepage distance based on pollution class
- Conductive rod diameter and type
- Testing for full wave impulse withstand voltage and thermal aging
We comply with GB, IEC, and ANSI standards, ensuring compatibility with both domestic and international installations.