ABB SF6 LTB 245E1 BLG 1002A, Product Manual

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Operating Mechanism Maintenance Maintenance
1HSB515409-100 en rev2
13
4.2.1 Emptying the gas
Work that involves a risk of damaging the insulators must not be carried out until
the gas has been evacuated to a pressure of max. 0.125 MPa (abs).
WARNING
Unused SF
6
gas is non-toxic, odourless and colourless. It is heavier than
air and can therefore easily collect in low-lying places, e.g. cable trenches,
tanks, etc., if released in large volumes
When large quantities of SF
6
gas collect in such places, a risk of
asphyxiation may occur due to a lack of oxygen.
The SF
6
gas is evacuated by using gas handling equipment, which cleans and
compresses the gas so that it can be reused or destructed.
N.B. Mixed gas, SF
6
mixed with N
2
or CF
4
, must not be reused unless the mixture
ratio is kept under control. (Can be checked with a meter that indicates the
percentage of SF
6
.)
4.3 Cleaning
• Clean the inside of the operating mechanism using a vacuum cleaner.
• Check that the filters in the valves are clean. If they are heavily soiled, they
should be replaced.
4.4 Corrosion
Some of the steel mechanism parts have been surface treated with manganese
phosphate and then rust protected by dipping in oil. This applies to, among others,
catches, gears and components in the link system.
Despite good rust protection, small signs of corrosion can appear after a number of
years, especially on circuit-breakers erected in very aggressive environments.
• Rust spots should be removed and new anti-corrosive agent should be applied
by brush or spray. Recommended anti-corrosive agents are Grease “G”
or
Tectyl 506.
N.B. After drying, Tectyl 506 forms a protective wax-like film and must not be
sprayed on bearings, catch gears, gears or chains.