LARGEST MOBILE TRANSFORMER

E&MP 40.039

Electric Transformers

August 10, 1959

THIS 40,000-KVA MOBILE TRANSFORMER, believed to be the world's largest, is now ready for service on the Pacific Gas & Electric Company's system in California.

Here workmen tap 115-KV line at Newark substation, San Leandro, for initial build-up test.

The forced-oil-cooled, single-phase General Electric autotransformer will serve as a mobile spare for the many large transformer banks on the PG & E system.

It can step down power from 230 KV to various voltages in the 120-, 60-, and 13.2-KV ranges.

Unit is mounted on rigid aluminum frame 42 feet long, which rides a jointed 32-wheel trailer.

Total weight of transformer-trailer is almost 56 tons. Aluminum tank and structural parts help keep weight down.

On the road the bushings and lightning arresters are braced and the rectangular Atmoseal* oil preservation tank is lowered to meet 13 1/2-foot height limit for highway vehicles.

Photo No. A180061

*Trade Mark of General Electric Co.

Original Caption by Science Service
^© General Electric Company