Glass Insulators


Grantel Equipamentos Toughened Glass Disc Insulators

Grantel Equipamentos expands its participation in the equipment and service market applied to electrical energy systems by bringing toughened glass suspension insulators from Global Group Company to the South American market.
With the approval obtained in all the type tests conducted at CEPEL and LACTEC, according to standards NBR 5032 and IEC 60383, a new option of ensured quality for toughened glass disc suspension insulators is available in the market.

Tests conducted

cepelRadio interference, dry lightning impulse withstand voltage, puncture withstand and wet power frequency withstand voltage.


lactecDimensional verification, mechanical failing load, thermal-mechanical performance, residual mechanical strength, thermal shock, impact and verification of the locking system.

Technical Catalog of Glass Disc Insulators

New products were tested at the most reputable laboratories in Brazil and Latin America, according to Standards ABNT NBR 5032 and IEC 383-1, and satisfied all the specifications required by the Standard.
These were presented to the market only after quality confirmation of the glass insulators by the laboratories and tests.

View Catalog of Glass Insulators

A successful partnership

A quality product manufactured by a renowned company with the best technological resources available in the market. Sold in the South-American market by Grantel, recognized for its technical capacity and professionalism: The Global Group – Chengdu Global Special Glass Manufacturing Co. is the branch responsible for the manufacture of toughened glass disc suspension insulators from Wuliangye Group, a corporation that acts in the beverage, packaging, engineering glass and crystal market with 500 million dollars in fixed assets and over 6 thousand workers.

“Renowned company with the best technological resources available in the market.”

With its most modern factory in Chengdu, result of the investment of 150 million dollars, the Global Group is able to produce up to 6 million international quality insulators per year, which were analyzed and duly adapted to the South American reality by the technical staff of Grantel Equipamentos. Highlighted among the most important activities used by the Global Group in the production of glass insulators are:

Sorg natural gas or diesel furnace – Germany;
Eclipse Inc. combustion system. – United States;
Mettler-Toledo dosing and weighing systems – Switzerland;
Waltec Forming and Heat Treatment System – Germany;
Glassware Machinery – Salvattore – Italy;
NiS crystal elimination system – developed by Global Group.

Counting on these state of the art equipments, the insulators produced have a spontaneous breakage rate below 1/10,000.


Audited System

In the assembly line, Global uses carefully prepared Aluminous Cement and an automatic curing water temperature control system. The technical staff from Grantel visited metal parts suppliers for insulators, confirming their good quality. Global Group was certified with the Quality Management System ISO 9000 granted by CNAS-China. Similar to its production system and suppliers, the Quality Management System from Global was audited by the technical staff from Grantel Equipamentos, which observed the adherence of procedures described in its quality manual with the records produced, confirming its conformity with the real activities produced during the production and quality control process for the glass insulators. Highlighted among the most relevant quality control equipments are:

X-Ray Diffractometer;

X-Ray Fluorescence Spectrometer;

Plasma Spectrometer.

These equipments, along with others in Global Group laboratories, have the capacity to analyze the compounds, effectively control the mass of various elements as well as detect rare elements in the glass. After factory approval, suppliers approval, quality system approval and the type tests approval from insulators prototypes 120, 160 and 240kN in CEPEL and LACTEC. Grantel performed one more test: Real supply of 20 thousand 120 kN insulators with zinc sleeve, purchased for Grantel stock with the purpose of meeting the urgent needs of our customers.

The insulators were produced and, after the ready and packed batch notice, an engineer from Grantel inspected the batch, monitoring the execution of all the receiving tests and conducting two other type tests: lightning impulse withstand voltage – up and down statistical method and puncture impulse with steep wavefront greater than 2500 kV per microsecond.

Therefore, we were able to check the conditions of the electrical and mechanical lab from Global Group, as well as evaluate the supply in terms of Quality. The entire batch was approved without requiring re-sampling. All the first samples passed in the conducted tests. Grantel proceeded with approving Global and ensuring its customers that the products supplied by it will always be of excellent quality and within the established standards.

Quality commitment

To maintain the level of quality, it is our commitment that Grantel will monitor the receiving tests at Global for all other supplies and eventually request additional tests according to the demands of our customers. Some significant results were obtained in the type tests in comparison to the minimum values required in NBR and IEC. These results confirm the quality of the Grantel-Global insulator:

Lightning Impulse Test – Determination of U50 – Up-and-Down Method
Short String of 5 Insulators without Zinc Sleeve
Obtained in the Type Test – CEPEL Minimum Defined by Standard NBR and IEC
120kN, Height 146mm 458kV 120kN, Height 146mm 410kV
160kN, Height 170mm 533kV 160kN, Height 170mm 440kV
240kN, Height 170mm 500kV 240kN, Height 170mm 440kV


Wet Power Frequency Withstand Voltage Test
Short String of 5 Insulators without Zinc Sleeve
Obtained in the Type Test – CEPEL Minimum Defined by Standard NBR and IEC
120kN, Height 146mm 211kV 120kN, Height 146mm 155kV
160kN, Height 170mm 241kV 160kN, Height 170mm 185kV
240kN, Height 170mm 236kV 240kN, Height 170mm 185kV

As observed in the direct comparison of the results obtained, the Grantel-Global insulators are well above the minimum required by NBR and IEC standards, exceeding the expectation with considerable gap. Copies of the results of the type tests at CEPEL and LACTEC can be kindly provided to customers who wish to further understand the details of the quality of our products.