circuits, a normal circuit and an emergency circuit. The panels serve important or critical loads, and should a normal main circuit to a panel fail, the panel through the transfer switch can be served by an alternate or emergency circuit. The apparent important or critical loads include sump pumps, elevator machinery, spillway gate hoist, ice-prevention system air compressors, and penstock gate hoists. The operation and control of the major portion of electrically operated equipment in the dam and related structures is normally accomplished by operation of controls locally provided at the location or site of equipment being operated. In a few instances, however, control circuits extend between equipment in the dam to control boards in the powerplant. The forebay (reservoir) water surface elevation is made available at a receiving instrument in the powerplant through a control circuit extending from a float-actuated transmitting instrument located in one of the penstock intake gate hoist structures at the top of the dam. From each of the three penstock gate hoist control cabinets located in the gate hoist structures of the dam, control circuits partially controlling penstock gate operation extend to main control board CCA in the powerplant. For each penstock gate, gate position indicating lights and a manually operable switch to effect emergency closure of the gate are provided at the control board. Also, at the control board, the control circuits are so connected that automatic closure of a penstock gate will be effected through operation of generator main overspeed switch, governor oil level switch, or governor oil pressure switch. These gate control circuits operate at 125 volts direct current, and the direct current is supplied by the powerplant station battery. Additional control circuits operating at 110 volts, 60 cycles, also extend from the penstock gate hoist control cabinets to the penstock filling line valve locations in the filling line gallery of the dam. Pressure switches connected to the penstock filling line piping are so connected in the penstock gate control circuits that a closed gate cannot be raised (opened) until the penstock associated with the gate has first been filled with water by means of the filling line valve. A control circuit is provided between the sump pump chamber in the dam and control board CCB in the powerplant. Abnormal high water in the drainage sump in the dam will cause a contact of the sump pump control float switch to close and thereby initiate an alarm signal at the control board. Further, should a thermal overload device in one of the sump pump motor starters operate, a contact on the device will close to initiate an alarm at the control board. The alarm control circuit operates at 125 volts direct current with the direct current being supplied by the powerplant station battery. Lighting systems employed in the dam and related structures provide general utilitarian illumination in galleries, adits, and machinery spaces in the dam; in rooms of the elevator and river outlet gate structures; on the crest roadway of the dam; on the spillway gate structure; and at the river outlet valve structure and the service parking area adjacent thereto. The lighting systems of the river outlet structures and the powerplant adit in the dam are served from lighting distribution panelboards in the powerplant. Otherwise, the lighting systems for the dam and related structures are served from distribution panelboards located in the gallery system of the dam and located in the elevator tower. The panels in the dam and tower are supplied through dry-type, air-cooled distribution transformers energized from the power distribution system in the dam and tower. The transformers are generally situated adjacent to the respective panels served by the transformers. The lighting system service voltages are nominally 208Y/120 volts, 3-phase, (4 wire, grounded neutral), 60 cycles, and all lamps energized from lighting system circuits are rated 120 volts. Lighting outlets within the gallery system of the dam consist generally of lampholder devices employing bare lamps. Lighting fixtures employed elsewhere are industrial and commercial types. Convenience outlets are provided in the same general areas and locations as are lighting outlets and fixtures. The convenience outlets are 2-wire, 3-pole, (grounded pole) types providing energy at nominally 120 volts, single-phase, 60 cycles at the outlet receptacles. All lighting system panelboards contain automatic-trip, molded-case-type circuit breakers which afford short circuit and overload protection to the branch circuits originating at and emanating from the panelboards. The major portion of branch circuits serving lighting outlets and fixtures are controlled by conventional lighting control switches. Switches are located at gallery entrances and intersections, and near or adjacent to access doors of rooms and compartments. From some of the longer circuits employed in the gallery lighting system, contactors are utilized to energize the circuits. The contactors are located in the panelboards and are controlled by conventional lighting circuit switches. The operation of crest roadway lighting units on the dam is controlled by a time switch located in the top utility gallery of the dam. The time switch controls operation of contactors provided in several of the panelboards in the utility gallery, and these contactors control energization of circuits serving the crest roadway lighting units. The units are mounted in the roadway parapets of the dam. The time switch is a synchronous motordriven type and has an astronomic-type dial. The on and off periods of the switch can be manually adjusted or set. Typical types of circuits employed for the electrical system in the dam and switching methods utilized appear on figure 143. The dam and related structures are provided with a grounding system which generally consists of main runs of bare copper cable extending exposed along galleries and otherwise embedded in concrete of structures. The main runs of ground cable extend from and are connected to the powerplant ground mat. Electrical equipment enclosures and cabinets, metal conduits, structure handrailings and metalwork, machinery bases, and crane rails are connected to main ground cable runs with branch ground cable taps and extensions to provide a basically common and interconnected grounding system. 3. Equipment in Diversion Tunnel 108. High-Pressure Gate and Hoist. One 2-foot 9-inch by 2-foot 9-inch high-pressure gate (figs. 17 and 144) was installed in the bypass conduit of the diversion tunnel closure structure for temporary use. The gate was operated by hydraulic hoist using hydraulic oil. When the diversion tunnel concrete plug was placed, the high-pressure gate was permanently closed and the hydraulic control piping removed. The net shipping weight of the gate and hoist was 13, 300 pounds. 109. Stoplogs. Eight stoplogs were furnished for the diversion tunnel closure structure (fig. 17) to provide a bulkhead at the diversion inlet when practicable to conform to construction schedules. The eight log sections, approximately 13.08 feet long by 5.86 feet high, as shown on figure 145, were furnished under invitation No. (D)90, 034-A. The stoplogs are installed in vertical guides on the face of the diversion tunnel closure structure; four stoplogs are placed in the guides of each of the two openings. Effective sealing is obtained by means of music note-type rubber seals bolted to the log sections. The stoplogs were designed for a head of 150 feet at safe stress. The estimated weight of the eight stoplogs is 66, 800 pounds. 110. Trashracks. One trashrack was furnished for the diversion tunnel bypass to protect the 2.75- by 2.75-foot high-pressure gate from oversize trash. The trashrack section, approximately 5. 33 feet wide by 5.33 feet high, as shown on figure 146, was furnished under invitation No. (D)90, 002-A. The trashrack is secured over the bypass intake by means of embedded anchor bolts. The rack consists of 4-1/2- by 1/2-inch trash bars supported on the ends by 5- by 3-1/2by 3/8-inch angles. The 3-7/8-inch clear opening between the trash bars was considered sufficient protection for the high-pressure gate. The trashrack was designed for a differential head of 40 feet at safe stress. The estimated weight of the trashrack is 750 pounds. F. Main Control and Protective Relaying Systems 111. General. Flaming Gorge Powerplant was designed to be operated as an attended plant with provisions for future addition of equipment to permit remote control as an unattended plant. The plant is to operate on an initial limited peaking, firm power seasonal basis. The output of the plant is restricted by the availability of water resulting from seasonal runoff. The units can be run as synchronous condensers when required. The plant was designed on the basis of one operator in attendance in the control room. There is sufficient control, indication, and annunciation equipment on the main control |