SF6 is an artificial, inert and generally non-toxic gas (Maximum Allowable Concentration (MAC) of 1,000 ppmv). It is a well-known greenhouse gas (GWP of 23,900 times higher than CO2), with an atmospheric lifetime of 3,200 years.

Because of its environmentally unfriendly attributes, SF6 was included in the Kyoto Protocol with the aim of emission reduction. Due to its excellent insulating and arc quenching properties, it is globally used as insulating gas in high and medium voltage equipment like substations, switchgears, circuit breakers, transformers etc.

The SF6-IR-Leak was particularly developed to pinpoint the smallest leaks of SF6. With its fast response time and clear down after saturation the SF6-IR-Leak is an ideal tool to reduce environmentally unfriendly and costly SF6-emissions.

Since more than 40 years, sulphur hexaflouride (SF6) is used in the electricity industry as insulated and quenching medium for gas insulated substations (GIS) and circuit breakers (GCB). Even under ecological aspects there is no alternative to SF6 available until today (life cicle assessment). Arcing processes that belong to the everyday operation of a GCB or partial discharge activity over a long period, cause the decomposition of the SF6 to highly corrosive and toxic by-products.

These decomposition products react with the inner components of the equipment and reduce their surface stability so that even mayor breakdowns can become the consequence.

The pre-requisite to form these decomposition products are reactants like water (H2O) and air (N2O).

Therefore, organisations like the CIGRÉ (SF6-Recycling Guide), SOLVAY FLOUR (SF6 Producer) and the IEC 60480, recommend to regularily check the concentration of decomposition products as well as of moisture and the purity of the SF6 applying a condition-based maintenance (CBM).

This can all be easily realised with the all-in-one product called SF6-Analyser.

Circuit breakers and SF6

A high productive circuit breaker factory for live tank air insulated breakers consumes approximately 50 tons of SF6 gas each year. A deadtank circuit breaker factory consumes 10 times that amount.

A single live tank air insulated circuit breaker contains somewhere from a few kilos up to a few tens of kilos. While a Deadtank breaker, as stated previously, consists of tens times that  much.

And as you may be aware of, a GIS substation can contain several tons of Sulphur Hexaflouride.

The need for analysing and securing this gas

Despite the international science community's efforts over decades to find a more enviromentally friendly version, they have been unsuccessful. Globally, we manufacture 7,500  tons each year and approximately 25% of those are used in new electrical apparatus. The rest is basically used to compensate leakage in old electrical apparatus. The total global leak rate is 5,000 to 6,000 tons/year.

Except the costs involved for any given company to fill and refill the switchgear, the costs for analysing and locating leaks must also be taken into consideration. Therefore, the need of reliable and smart equipment is relevant, not only to cut costs but also to save our environment. The SF6-Analyser and SF6-IR-Leak helps you achieve this.