High-voltage transformers and protective and controling apparatus for outdoor installation

Outdoor or weatherproof transformers for ordinary distributing purposes, and for potentials up to about 2500 volts, have long been in general service. With the exception of arc lamps and series incandescent lamps, transformers have been about the only apparatus in high-tension service not protected by buildings. Distributing circuits operating at 6600 volts are now quite common. There are also a few 10,000-volt, and a small number of 15,000-volt distributing systems using outdoor transformers.