Why Quadri*Sil™ Insulators Provide Longer life

Today’s fourth generation Quadri*Sil™ polymer transmission insulator has an expected service life of more than 50 years. It results from 100+ years of experience designing and manufacturing insulators, including 40 successful years developing polymers.

With all the outside environmental factors that negatively influence insulator life, it’s imperative for manufacturers to understand how these interact with the material. Effectively addressing it in material and design ensures peak performance. The field service data gained over nearly 50 years has been invaluable for improving materials, design, testing procedures and manufacturing processes.

Our experience provides sound guidance for performance and life expectations. How did Hubbell create the Quadri*Sil insulator with this prolonged life and performance? Let’s take a quick look at the factors determining the life of a polymer insulator. For an in-depth discussion, please read the detailed white paper. 

Stressing the application

An insulator is a mechanical device which must survive three radically different types of stress.

• Mechanical stress, or mechanical force applied to the bearing element
• Environmental stress, specifically UV radiation and contamination
• Electrical stress, including leakage currents, corona, and dry band arcing

The fiberglass rod inside an insulator is the primary source of mechanical strength, along with the end fittings. The polymer housing protects the fiberglass rod from the environment and provides the electrical characteristics.

Materials that stand up to the environment

For Quadri*Sil insulators, accelerated testing is completed as part of regular performance verification. In previous blogs, we’ve discussed the essential elements for compounding and testing polymers that will provide superior insulator performance in the field.

Superior physical construction

Every element of the insulator design has been developed to enhance performance over previous generations. These include the polymer weathershed profile, shed spacing, material properties, geometry of the end fitting, and more.

Our engineers designed a four-seal redundant system as a more secure means to prevent moisture from penetrating to the fiberglass rod at the critical triple point. This is where the rod, end fitting and polymer all contact each other. Improved end fittings further protect the triple point from the damaging effects of electrical activity such as corona and high-power flashover.

Wrap up

Continuous development and testing, backed by field experience, support the 50+ year life expectation for Quadri*Sil polymer transmission insulators. Test results show our insulators surpass many thresholds set by previous generations by a wide margin.

See the results for yourself. Discover the Quadri*Sil design elements and how the materials faired in performance testing in our white paper “Life Expectancy of HPS Quadri*Sil Polymer Transmission Insulators.” 

To learn the complete story about polymer insulators, be sure to sign up for our six-part educational series. We’re here to help.

To talk to someone about your transmission insulator needs, please reach out to your Hubbell sales rep.