10.May
How the EN 60099-4 Standard Revision Validated the Superior Quality of Protektel® Arresters
The second edition of the EN 60099-4 standard introduced changes that posed challenges not only for surge arrester manufacturers but also for their customers. Even today, we receive inquiries about the specifics of this revision and its impact on our products. Interestingly, these changes have highlighted the superior quality of Protektel® arresters. Read on to discover more about this topic and understand why our company is synonymous with unlimited confidence.
Navigating the Stricter Standards
All surge arresters must meet global standards, yet most manufacturers focus on minimizing production costs while ensuring their designs pass the required laboratory tests. But what happens when standards become more stringent? At Protektel, we have the best answer to this question, as detailed in the following article.
Key Changes in the EN 60099-4 Revision
To illustrate, let’s examine the specific changes in EN 60099-4. This standard addresses the classification of non-directional surge arresters based on non-linear metal oxide varistors supplied with AC voltage above 1 kV.
First published in 2004, with a subsequent revision in 2005, the latest edition came out in 2016. This most recent revision introduced significant changes in the classification and type testing of surge arresters, as outlined in the tables below.
Table 1: New Classification of Surge Arresters
| Class | Stationary | Distribution | ||||
| Designation | SH | SM | SL | DH | DM | DL |
| Rated current discharge 8/20μs | 20 kA | 10 kA | 10 kA | 10 kA | 5 kA | 2,5 kA |
| Qrs [C] | ≥ 2,4 | ≥ 1,6 | ≥ 1,0 | ≥ 0.4 | ≥ 0,2 | ≥ 0,1 |
| Wth [kJ/kV] | ≥ 10 | ≥ 7 | ≥ 4 | — | — | — |
| Qth [C] | — | — | — | ≥ 1,1 | ≥ 0,7 | ≥ 0,45 |
| SH — Station High, SM — Station Medium, SL — Station Low DH — Distribution High, DM — Distribution Medium, DL — Distribution Low | ||||||
Table 2: Changes in Type Tests of Surge Arresters
| Test name | Status of changes | Comments |
| Reduced voltage test | Change | A simpler method for determining the voltage level of steep surge protection. The value of the switching reduced voltage is measured only at one switching surge current for station arresters, it is not necessary to measure for distribution arresters |
| Attempt to verify the long-term stability under the voltage of continuous operation | Significant change | Previously, it was part of the operation test and concerned the determination of power losses in varistors. Now a factor derived from the voltage distribution on the arrester has been introduced, and the test evaluation criterion has been tightened. |
| Repeatability of charge flow Qrs | New | The test replaces the Long Duration Impulse Current Tests. There is a requirement to increase the number of samples tested. It is allowed to damage 1 sample out of 10 tested. If damage occurs to 2 of them, another 10 samples should be tested, which can no longer damage themselves. |
| Heat dissipation by the tested sample | Change | Previously, it was part of the performance test. The new approach is to define a thermal model for the arrester and the section to be tested. |
| Operation test | Significant change | The test sequence has been modified, and new criteria for load and rated thermal energy have been introduced for the thermal model of the arrester. |
| Test of the arrester line frequency voltage characteristics as a function of time | Significant change | The previous version of the standard left discretion in conducting this test. The new one, on the other hand, requires that the manufacturer publish the TOV (Temporary Overvoltage) characteristics to the rated voltage Ur, based on, at least, 4 verified points in the range: 0.1s, 1s, 10s, 100s, and 1000s. |
| Test of disconnects/limiter fault indicators | Significant change | The new test of disconnectors/limiter fault indicators consists of supplying Qrs load and Wth energy or Qth load. As in the previous version, the time-current characteristics must be determined for three current values of 20A, 200A, and 800A. Tests for bending moment, torsional moment, and longitudinal stress have also been added. In addition, temperature tests in cycles and a leakage test for the moisture-pumping phenomenon. |
Reasons for Changes in Surge Arrester Classification
The EN 60099-4 changes aimed to standardize testing methodologies, including thermal models for surge arresters. The effectiveness of heat dissipation largely determines the operational longevity of a surge arrester.
The primary goal of these changes was to eliminate low-quality surge arresters from the market. The new, more stringent requirements particularly affected low-budget manufacturers.
Impact of the Standard Revision
Manufacturers were the most affected by the EN 60099-4 revision, as they had to ensure their arresters met the new requirements, often necessitating higher quality varistors. This change required recertification of the new devices, which was time-consuming and costly.
End users, on the other hand, benefited from the new requirements. The inclusion of thermal characteristics in the classification meant that higher quality arresters were now available, resulting in longer periods of trouble-free operation.
High Quality of Protektel® Arresters Confirmed
With an understanding of the EN 60099-4 revision, we can explain how these changes validated the quality of Protektel® arresters. During the design phase, we faced several dilemmas, especially regarding the quality of varistors: should we opt for components that met existing standards or higher quality ones? Choosing the latter allowed us to avoid risks associated with future standard changes.
The confidence you place in our surge arresters stems from their quality, which is rooted in both innovative design and premium components. From the beginning, we have selected only the best components. This is confirmed by the latest EN 60099-4 standard tests, which our arresters passed effortlessly, maintaining reserves of 20-30% in key performance areas. Such results are hard to surpass in our industry, wouldn’t you agree?