SF6 circuit breakers

SF6 CB is more or less a trouble free switching system. Gas leakage is to be checked in regular intervals . Under low pressure or no gas conditions there can be short circuit of pole contacts and can cause bursting if operated under such conditions. At sub zero temperatures conditions the gas may liquefy and cause problems. But in tropical countries SF6 breakers are found to work with out temperature related defects.

SF6 itself is a gas with no color, no odor and innoxious. Equipment installed in an enclosed space, if leaking, may cause deoxygenation hazardous to the operators.

When the gas is exposed to the electric arc, the resulting noxious contaimination could be deadly harmful if leaked.

In opeartion, SF6 equipment need to be checked regularly for leakage with SF6 detector, and for water content usually with dew point meter.

I understand in any standard manufacturer product onSF6 breaker gas low pressure alarm and very low pressure blocking of operation is envisaged. Also SF6 detector is an additional advantage. In case of GIS, there is SF6 gas pressure monitoring in each sections of GIS and isolation of section is possible for maintenance.