EQUIPMENT AND TOOL REQUIREMENTS IN GAS INSULATED SUBSTATION CONSTRUCTION BASIC INFORMATION AND TUTORIALS

Cranes or hoists having adequate lifting capacities should be available for handling material during installation. Nylon web slings provide an ideal means for lifting equipment without damaging it.

Gas is handled through commercially available gas-processing trailers that contain vacuum pumping equipment, gas storage tanks, compressors, filters, and dryers. The size of the individual gas compartments and the evacuating and storage capacity of the gas-handling equipment is especially important in large stations.

Suitable evacuating equipment and a heat source to counteract the chilling effect of the expanding gas may permit filling directly from gas cylinders or gas-handling equipment. High-voltage test equipment is required for checking the quality of the insulation after installation.

Adapters for high voltage testing may be required. These include a suitable entrance bushing for connecting the high voltage to the gas insulated conductor and a termination for closing off the end of the equipment when the entire assembly has not been completed. In many cases, it may be possible to use an entrance bushing that is a part of the installation.

When tools and alignment templates not readily available on the open market are required for installation and maintenance of the equipment, one set should be furnished, by the supplier, with the equipment when it is delivered.

The following materials should be on hand before the bus is opened:

a) Gas-processing equipment with adequate storage capacity

b) Electrolytic or electronic hygrometer or comparable equipment for measuring moisture levels

c) Insulating gas leak detector (Where double “O” rings are used, a manometer can sometimes be connected at the sensing hole to measure any increase in pressure between the “O” rings. Commercial high-viscosity, noncorrosive solutions may be used to locate larger leaks at a sensing hole, at welds, or at bolted flanges.)

d) Dry air

e) Clean plastic gloves and work uniforms

f) Lint-free cloths and manufacturer-recommended solvents

g) Temporary plastic bags or covers for sealing openings after components have been removed

h) Commercial-type vacuum cleaner with high efficiency particulate air (HEPA) filters and nonmetallic

accessories

i) Tools supplied and recommended by the manufacturer

j) Ventilating equipment

k) Handling and lifting equipment

l) Maintenance manual and erection drawings

m) Ladders and platforms as required