SF

6

/N

2

gas mixture has good insulation performance and a certain opening and closing current capacityand can reduce the sensitivity of local electric field distortion

solve the liquefaction problem of SF

6

gas

can re-duce greatly the

use and discharge of SF

6

gas and reduce the greenhouse effect to the environment

which is of greatsignificance for strengthening energy conservation

emission reduction and achieving low-carbon development.In re-cent years

in response to the national call of energy saving and emission reduction

State Grid Corporation of Chinahas organized the work of using SF

6

/N

2

gas mixture for GIS bus

disconnector and earthing switch.An uniform 30%mixing ratio（SF

6

:N

2

=30%:70%）is used in GIS bus

disconnector and earthing switch.Products from multiplemanufacturers have passed type tests and technical appraisal of new products and engineering trials have been car-ried out in substations.In order to study the operation and maintenance method of GIS equipment

based on asealed trigger gap

the arc fault of GIS equipment is simulated in this paper

the decomposition products of SF

6

/N

2

gas mixture under the action of arc are analyzed and the characteristic components and change trend of decomposi-tion products are studied.Compared with the decomposition products of SF

6

gas under the same conditions

the dif-ference of GIS equipment operation and maintenance between SF

6

/N

2

gas mixture and SF

6

is proposed.The decom-position products of SF

6

/N

2

gas mixture in GIS disconnector and earthing switch after opening and closing currenttype test are tested and analyzed to judge the decomposition products of GIS disconnector and earthing switch dur-ing the normal opening and closing current process.