Number
341-EN
Section
General Section
Use
Sector
Manufacture of computer, electronic and optical products, electrical equipment
Function
Other
Process
Other
Product category
other
Application
Switchgears
Abstract
Sulphur hexafluoride (SF6) has properties that made it used on a large scale in various applications, including as insulator in electricity power systems. Since it has been proven to be a very powerful greenhouse gas, alternatives were sought. Dry air can be used to substitute SF6 in electric switchgears.
Substituted substances
Sulfur hexafluoride
CAS No. 2551-62-4 EC No. 219-854-2 Index No.
Chemical group
Sulfur compounds; fluorine compounds
Reliability of information
Internet information: data are from an internet document and only a basic and partial evaluation could be performed
Reason substitution
ecotoxicity
Other type of alternative
Dry air
Hazard Assessment
Substance to be substituted: Sulphur hexafluoride is a very powerful greenhouse gas, but has low toxicity and flammability. In the EU, regulation (EU) No. 517/2014 specifies restrictions on use of fluorinated greenhouse gases. Alternative substance: Dry air is not toxic, not flammable and is not a greenhouse gas. All pressurised gases should be handled with care.
Description of Substitution
Sulphur hexafluoride (SF6) has very good electrical insulating properties, is odourless and has low toxicity and flammability, which makes it a very good choice for switchgears. It is however a very powerful greenhouse gas. Pressurised SF6 insulation in switchgears can be replaced by dry air insulation. According to the producer, a proprietary technology allows using low-pressure dry air as an efficient alternative to SF6. The technology allows the use of thinner containers, therefore reducing the weight and volume of the gear.
Case/substitution evaluation
Circuit breakers are essential for the safety of electrical gears, especially for high voltages. The continuous and accelerated development of civil and industrial electric networks generates concerns regarding their impact on climate and environment. Using SF6 as insulator is part of the impact, even if, currently, its contribution is still low, compared to that of the whole process. Air has a lower dielectric strength, which is a disadvantage compared to SF6. Still, because dry air is practically hazardless, the technologies that make it possible to use it as an insulator, while meeting electrical safety standards, should be considered as alternatives.
State of implementation
In use
Availability ofAlternative
The alternative is available on the international market
Producer/Provider
Type of information supplier
Producer / distributor
Further information
Dry-air Insulation Technology http://www.mitsubishielectric.com/bu/powersystems/technology/switchgear/dry_air/index.html
Publication source: author, company, institute, year
The description is based on the presentation Guide to environmental technologies - Dry air insulated switchgears, published by the producer, Mitsbubishi, on its website.
Date, reviewed
November 26, 2021