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1302 134 METROPOLITAN WATER DISTRICT , tribution line is constructed with No. 2/0 copper conductor on pin- type insulators. The 33-kv tap lines carrying current from the 33-kv distribution lines to the 33/2.4-kv substation of each power user are generally of single pole, flat construction with No.2 cop- per conductor on pin-type insulators. The total length of 33-kv line is 280.5 miles, consisting of 226.8 miles using No. 2/0 con- ductor and 53.7 miles using No.2. The original transmission lines listed in the preceding paragraph were constructed in 1933 and were all built by contract, the District supplying poles, insulators, and conductor, and the contractors sup- plying all other material and the necessary equipment and labor to complete the work. Subsequently, 16 miles of 33-kv tap lines re- quired to supply power to tunnel, canal, conduit, siphon, dam, and ]lumping plant schedules were built by District forces. Transformer banks of 6,000-kva capacity at Lakeview, Cabazon. Fan Hill, Hayfield, and Granite substations tie the 66-kv and 33-kv systems together. At the 6,000-kva Parker substation the voltage is stepped down from 33 kv to 11.5 kv to operate a 5,000-kva synchronous condenser. To supply power for tunnel, canal, con- duit. and siphon operations, aggregate plants, District headquarters camps, wells and boosters, Parker dam, and pumping plant con- struction, substations ranging in capacity from 20 kva to 2,000 kva deliver power from the 33-kv lines at 2.4 kv. Synchronous condensers of 5,000-kva capacity were installed in the Lakeview, Fan Hill, and Parker substations to assist in the maintenance of a high-voltage level throughout the system. Tap- changing autotransformers were installed in Fan Hill, Hayfield, and Granite substations as auxiliaries to the regular transformer banks. These make it possible to control voltage conditions on the local distribution systems independently of the operation of the synchronous condensers, which consequently can be operated in a manner best suited to the needs of the power system as a whole. The lines east of Cabazon are protected by instantaneous over- current relays set to operate on faults occurring in 80 per cent of each section. They are supplemented by a conventional in- stallation of inverse-time overcurrent relays. By the use of the in- stantaneous relays, clearances have been obtained as quickly as 9 cycles, which minimizes the tendency for synchronous equipment to drop off the line on a voltage dip. In the loop between Colton and Cabazon phase directional relays are used, and also ground '1 II ~ " , I