Aldridge, recently completed the construction of a new 345kV GIS (Gas Insulated Switchgear) substation in Waukegan, IL.  Additional work included above grade electrical construction of a new 138kV Switchyard adjacent to the GIS substation.

The contract is part of a program which will increase the reliability of electricity delivery within northeastern Illinois.  The use of various gases to insulate major electrical components is a very effective engineering design solution. It can significantly reduce the footprint necessary for switchgear and associated stations, thus saving both cost and space. With the use of pressurized sulfur hexafluoride (SF6) to insulate the conductors and contacts, the space required for a GIS substation becomes a fraction of previous requirements without decreasing the voltage level.