machine shop at elevation 3123.67. No unusual difficulties were encountered during this installation phase.

Other components of the oil handling system were installed by the completion contractor, Ets-Hokin Corp., under specifications No. DC-5750, as follows:

(1) A portable oil purifier was furnished by DeLaval Separator Co. of Chicago, Ill., under invitation No. (D) 90,578-A. The purifier is capable of handling 1,200 gallons per hour of transformer oil and 600 gallons per hour of governor and lubrication oil.

(2) One 50-g.p.m. transformer oil transfer pump and one 30-g.p.m. lubricating oil transfer pump were furnished by Colorado Pump and Supply Co. of Denver, Colo., under invitation No. (D) 90,583-A.

(3) One filter paper drying oven was furnished by L. A. Greene-Bowser, Inc., of Cookeville, Tenn., under invitation No. (D) 90,624-A.

(4) The metal piping to the generator housing, turbine pit, and governor cabinet was furnished and installed by a subcontractor, Detweilers, Inc., of Idaho Falls, Idaho, under specifications No. DC-5750.

Installation of the equipment and piping was substantially completed between August and September of 1963, with no difficulties being encountered except for some minor initial troubles in testing the oil purifier. A few of the top disks in the purifying bowl were damaged due to probable mismatching of parts by the manufacturer, but these were corrected in the field.

The most significant difficulty encountered with the oil system occurred after installation by the completion contractor, when clean oil became contaminated in the supply piping between the purifier and the units. Initially, the contractor had cleaned the oil piping according to the requirements of the specifications. This procedure provided that the piping was to be dismantled after erection, cleaned, and then reerected. The steps in the cleaning procedure were to use a rotary wire brush, blow out the piping with compressed air, swab with a cloth impregnated with solvent, and then swab with dry cloths. The cleaning and erection process for this piping extended over a period of approximately 3 months from August to

November 1963. During that time the open ends of completed portions of the piping runs were covered with a heavy tape, which appeared to be adequate to keep out foreign matter. The first oil was not introduced in the piping system until April 1964, when the piping was subjected to a pressure test. Several of the flanged joints had minor leaks which were promptly corrected.

In preparation for filling the oil requirements of generating unit 1, oil was circulated from the storage tanks through the purifier, down the main headers, and back to the storage tanks. Samples taken during a period of 5 to 6 weeks, while this filtering operation was in progress, revealed visible metallic particles which had the appearance of oxidized iron flakes. Moisture had apparently entered the piping at the taped openings or through loose flanged joints, during the time between the cleaning procedures and the first time oil was put in the system. In order to fill the unit oil sumps on schedule, a small terminal purifying unit was used just ahead of the unit piping for each unit. This terminal filtration procedure was also used in filling the transformers with insulating oil.

231. UNIT LUBRICATING OIL SYSTEM. The unit lubricating system is a key section of the overall oil handling system and extends from the headers servicing the units to the governors and to the generators and turbines. The generator thrust bearing is an immersed type with inherent oil circulation, and the capacity of the oil reservoir is 2,100 gallons. A self-contained high-pressure oil system is provided for the thrust bearing shoes to force oil between the bearing surfaces prior to starting and during shutdown of the generator in order to maintain a full thickness of oil film between the bearing surfaces. The upper guide bearing and lower guide bearing of the generator, also of the immersed type, have oil reservoirs around the bearings to allow for circulation of oil during rotation of the main shaft. The turbine guide bearing is lubricated by a pressure oil circulating system with two motor-driven oil pumps-one alternating-current pump for normal operation and one direct-current pump for emergency operation. The oil leaving the bearing drains back to an oil reservoir in the turbine head cover. There are provisions made for controlling the low temperature of the oil to assure lubrication on quick starts of the unit. During the first start of the units, the cleanliness of the oil from this system was questioned by the erection engineers of the turbine and generator manufacturers. This problem was resolved by the use of a small portable filter placed at a point where oil enters the bearing.

Oil storage, purifying, and transfer facilities are provided for handling the oil for the main power transformers, each with a capacity of 7,600 gallons. The system was placed so unfiltered oil cannot enter the filtered oil lines. The transformer oil storage room contains two 10,000-gallon transformer oil storage tanks, one for filtered oil and the other for unfiltered oil. Return piping from the main power transformers is not provided. The oil purifier room contains a 60-gp.m. transformer oil transfer pump, supplied by Colorado Pump and Supply Co. under invitation No. (D) 90,583-A. When a transformer is to be drained or filled with oil, it must be moved on tracks into position near the oil unloading pit and flexible hose connections made between the transformer and the pump. The transformers are provided with filter press connections, so a portable purifier can be used on the transformer deck.

232. AIR COMPRESSOR INSTALLATION. Compressed air is provided for the operation of generator air brakes, charging of the governor pressure tanks, operation of air tools from service outlets located throughout the powerplant, operation of turbine grease pumps, operation of generator cooling water system controls and air conditioning system controls, and depressing the draft tube water during synchronous condenser or standby (spinning reserve) operation. The major items of Government-furnished equipment were installed by the

completion contractor.

The high-pressure air supply consists of one stationary 20-c.f.m., 375-p.s.i., two-stage, water-cooled air compressor with aftercooler, and a horizontal air receiver, 18 inches by 6 feet, to supply air for changing the governor pressure tanks and to furnish standby emergency air supply for switchgear equipment on the generator floor. This equipment was supplied by Compressor Service Co., Los Angeles, Calif., and I. G. Downs, Inc., on invitations No. (D) 90-581-A-1 and No. (D) 90-581-A-2.

The service air, generator brake air, and draft tube depressing air systems consist of three stationary 100-p.s.i. air compressors. One is a 100-c.f.m., single-stage horizontal, water-cooled compressor with one air receiver, 48 inches by 12 feet; and two are 500-c.f.m., two-stage, horizontal, water-cooled compressors with two air receivers, 48 inches by 12 feet.

The brake air system has two air receivers, 30 inches by 7 feet, checked off from the main service air system so that proper pressure will be available for the

generator air brakes. This equipment was suppliec under the invitations previously mentioned.

The draft tube depressing air system has four air receivers, 66 inches by 18 feet, checked off from the main service air system. This depressing air system is provided in order that the units may operate as sychronous condensers or motoring, using a minimum of power. Initial unwatering to depress the water leve in the draft tube below the level of the turbine runner is supplied by the stored air in the receivers.

No particular difficulties were encountered during the conventional methods of installation and testing used. The completion contractor's installation work consisted of moving the equipment to the powerplant, placing it on prepared foundations, and providing initial servicing and equipment for operations.

233. AUXILIARY AND SERVICE WATER SYSTEMS PUMP INSTALLATIONS. There are a large number of pumps installed in the equipment operating in the powerplant. The major water handling units are the generator cooling water pumps, the drainage and unwatering pumps, and the domestic water supply booster pumps.

Nine 2,200-g.p.m. generator cooling water supply pumps were furnished on invitation No. (D) 90,601-A by Aurora Pump Division of New York Air Brake Co. of Aurora, III. The centrifugal pumps take water from the draft tubes under a positive suction pressure and deliver it to the generator air coolers. Eight of these pumps were installed along with the unit piping in 1963, with one pump to be used as a spare. No significant installation difficulties were encountered.

Drainage and unwatering sump pumps were installed in both the powerplant and dam by the completion contractor. Two 2,900-g.p.m. deep-well turbine pumps were installed in the dam for unwatering the foundation sump. The two pump units are controlled by a float switch with automatic alternator. If one pump fails to keep the sump water level below a set point, an alarm sounds and the second pump will start. Two 500-g.p.m. and two 100-g.p.m. pumps were installed in the powerplant sumps. The pumps were furnished under invitation No. (D) 90,585-A by Fiese and Firstenberger Manufacturers, Inc., of Fresno, Calif. The operation is by automatic floatswitch control.

Four 920-g.p.m. centrifugal multistage booster pump units were installed to pump water to the Page water plant. Furnished by the G. M. Wallace Co. of Denver, Colo., under invitation No. (D) 90,622-A, the

Dumping units were installed, serviced, and tested by he completion contractor.

234. STATIONARY CARBON DIOXIDE FIRE EXTINGUISHING SYSTEM. The carbon dioxide fire extinguishing system was installed to provide automatic fire protection for the generators and oil handling rooms. These systems were installed by the completion contractor and were furnished by the Cardox Division, Chemetron Corp., under invitation No. (D) 90,606-A. The generator system is made up of an initial and a delayed discharge of gas. The initial discharge of the gas is initiated by thermal switches in the generator air housings. The electrical controls cause operations of the discharge heads in the cylinders at the cylinder bank and open the proper selector valve to I direct the gas to the generator where the signal originated. This system can be operated manually from remote control switches, but the routing valves must also be operated manually. The delayed discharge is operated manually at the cylinder bank as required to control the amount of carbon dioxide in the generator. Each bank of initial and delayed discharge cylinders protects two generators through selector valves automatically, or manually, operated to discharge gas to a unit.

A separate group of cylinders was provided for the oil purifier room. Discharge is automatic subsequent to operation of water sprinklers in the room activated by fusible links. The flow of water through a waterflow switch closes a contact of an electric timer switch. After a 5-minute delay, a weight-operated valve is actuated by the electric timer and shuts off the supply of water to the sprinkler system, simultaneously actuating a solenoid valve to control the discharge of carbon dioxide to the oil handling rooms.

235. POWERPLANT MACHINE TOOLS. The following new machine tools were furnished by the Government and were installed in the powerplant by the completion contractor:

15-inch pedestal drill press

11- by 11-inch power hacksaw

300-ton hydraulic shop press with 5-ton arbor press 2-inch pipe and bolt threading machine Electric heat treating furnace 24-inch vertical drill press

The completion contractor also installed the following used machine tools which were obtained from the Naval Gun Factory, Washington, D.C.:

16-foot boring mill with a 320-kilowatt semiportable motor-generator set 36- by 144-inch-centers lathe 20- by 72-inch-centers lathe Milling machine

4- by 8-foot surface plate 6-foot radial drill

No. 2 cutter and tool grinder 10- by 1-1/2-inch pedestal grinder 12- by 2-inch pedestal grinder 16- by 30-inch-centers lathe 36-inch heavy-duty shaper 35-ton hydraulic straightening press 6- by 18-inch surface grinder

The installation of the machine tools consisted of leveling, locating floor anchoring if required, and servicing in accordance with manufacturer's instructions. The installation of the new tools was performed without difficulty. Some difficulties were experienced with the used tools, primarily due to lack of detailed manufacturer's instructions and parts lists and lack of repair parts on obsolete equipment.

2. Miscellaneous Electrical Equipment

236. GENERAL DESCRIPTION. The eight generators for Glen Canyon Powerplant were installed in a single row at finish floor elevation 3168.50. Located just downstream from the generators, an electrical gallery at this same floor elevation contains the generator switchgear. The 12 power transformers are located outside the building on the deck 20 feet above the switchgear in the electrical gallery. The isolated-phase bus, mounted on the downstream wall of the powerplant, provides the electrical connection between the power transformers and the generators. Each pair of generating units is connected to a single bank of three single-phase power transformers. Power is generated at 13.8 kilovolts by each of the eight generating units and is transformed to 345 kilovolts at units 1 and 2, 3 and 4, and 5 and 6, and to 230 kilovolts at units 7 and 8. Station-service power is taken off the bus of units 3-4 and 5-6. All major items of electrical equipment were furnished by the Government and were installed by the completion contractor under specifications No. DC-5750.

237. GENERATOR SWITCHGEAR AND BUS STRUCTURES. One station-type switchgear assembly for each generator was furnished by General Electric Co. under invitation No. DS-5828 and the eight

assemblies were installed by the completion contractor. Each assembly contains a 7,000-ampere air-blast circuit breaker, disconnect switch, current transformers, forced air cooling equipment, and provisions for connection to the isolated phase bus and generator protective cubicles. The switchgear for units 1, 3, 5, and 7 also include bus potential transformers used for synchronizing transformer metering and relaying.

Manufacture and shipment of the switchgear were scheduled in pairs to accommodate the installation of associated isolated phase bus, power transformers, and shunt reactors. The switchgear equipment was shipped assembled in two major components: the circuit breaker and disconnect switch in one part, and the bottom frame the other. A third section, the potential cubicle, was also shipped for four units. The first major shipment, which was the complete switchgear for units 1 and 2, arrived at Flagstaff railhead on August 29, 1963. The equipment for units 7 and 8 arrived in September 1963; unit 4 in November 1963, unit 3 in December 1963, and units 5 and 6 in July 1964.

The equipment was trucked to a temporary site storage area by the completion contractor and then moved into the powerplant after the base channels were set and grouted. Because of limited head room at the opening to the electrical equipment gallery at the generator floor level, it was necessary to move the breaker cubicle into position with small pipe rollers. Each breaker was then raised, the bottom frame placed on the base channels, and the breaker lowered to the bottom frame. The contractor fabricated a special lifting beam and A-frame to facilitate this installation work.

The switchgear was assembled in the energization sequence schedule for the switchyard and transformer circuits; namely units 1, 2, 7, 8, 3, 4, 5, and 6. This installation work started on March 10, 1964, and proceeded through August 1964, under the supervision of the manufacturer's erecting engineer. Final functional and timing checks of each breaker were performed just prior to placing the unit in service.

The switchgear and generators are connected to the power transformer by the isolated phase bus furnished by Westinghouse Electric Corp. under invitation No. DS-5828. The generator surge protection equipment, metering and relaying potential transformers, a bus. ground switch, and connection terminals were included as part of the isolated phase bus.

The first shipment of bus arrived at the railhead on September 6, 1963, for use on units 1 and 2. The

shipment for units 7 and 8 arrived on September 30, and other shipments arrived in November 1963 and June 1964. Several shipments sustained severe shipping damage, which was repaired in the field by welding or replacement of parts. The bus was shipped in sections convenient for handling and loading and the ends were covered and taped. Most of these protective covers were torn open during shipment and extensive cleaning of the interior of the bus housings was necessary.

In order to deliver power at 230 kilovolts from units 5 and 6 pending completion of the Pinnacle Peak 345-kilovolt additions, an additional section of bus for a temporary connection between units 6 and 7 was obtained on an order for changes to invitation No. DS-5828. This bus section was received and installed in May 1965.

Installation of the bus structures was accomplished by the completion contractor under specifications No. DC-5750. Services of the manufacturer's erecting engineer were utilized for approximately 65 percent of the installation work. In addition to repair of shipping damage, the erector corrected fabrication errors and omissions. Owing to the large size of the prefabricated sections, the bus and supporting frame were erected with a rubber-tired mobile crane utilizing conventional structural steel erection methods.

During erection of the bus, considerable difficulty was encountered in obtaining an adequate seal at the gasketed joints in the bus housing. Probably because of temperature cycling, the gasketed joints would not remain airtight. The positive pressure dry air supply system was therefore overloaded and ineffective, resulting in a number of air compressor failures during the first 6 months of operation. After many attempts to correct the leakage, the manufacturer proposed a redesign of the air supply system which included a high-volume low-pressure blower, a dehumidifier, and larger supply headers. A trial installation was made and found to be satisfactory. Modification of all units was completed by February 1967, and this work was performed under the equipment warranty.

All the bus structures were high-potential tested after completion of installation, and successfully withstood the 50-kilovolt tests. The The original installation of the bus for units 7 and 8 included taps to shunt reactors which were in service until August 1965. When the reactors were no longer required, the bus sections were removed and permanent end caps were placed on the taps near the power transformers.

238. POWER TRANSFORMERS. Nine 100,000-kv.-a. single-phase power transformers, rated 345 kilovolts on the high side and 13.7 kilovolts on the low side, were furnished by Pennsylvania Transformer Division of McGraw Edison under schedule No. 1 of invitation No. DS-5780. Transformers for the fourth circuit (fig. 291), rated 100,000 kv.-a., 230 kilovolts to 13.8 kilovolts, were furnished by Westinghouse Electric Corp. under schedule No. 2 of invitation No. DS-5780.

The first shipment of the 345-kilovolt transformers from Pennsylvania Transformer arrived at the railhead in June 1963. One 276-kilovolt lightning arrester was damaged and required replacement. During September three more transformers arrived, and again one 276-kilovolt lightning arrester was damaged. The last three transformers required on schedule No. 1 arrived in late November and early December. The three 230-kilovolt transformers furnished by Westinghouse arrived at Flagstaff on October 4, 1963. The only visible shipping damage was a small crack in a weld near the base of the transformer. The tank still held nitrogen pressure and no internal damage was anticipated. The transformers were stored at the

Figure 291.-High-tension bushing being raised into place on transformer K7A. P557-420-9847, June 10, 1964.

railhead until installation was started in June 1964. The 230-kilovolt Westinghouse transformers were hauled to the powerplant on conventional lowboy trailers.

Assembly of the 230-kilovolt transformers for units 7 and 8 began on June 6, 1964, under the supervision of a Westinghouse erecting engineer. The internal inspection of the transformers revealed that one set of high-voltage bushing current transformers had broken loose from the support brackets and fallen to the top of the winding. It was necessary to replace the current transformers and make extensive field repairs to insulating barriers and spacers and lead insulation. As was the case under similar conditions in transformer KU5A in the switchyard, the transformer access manhole was not large enough to permit removal and replacement of the damaged current transformer. As a part of the replacement procedure a new manhole was cut in the top of the transformer. New manholes were not installed on the other two transformers, but the necessary materials were furnished so that the manholes can be installed if they are ever required. Completion of assembly of the transformers was delayed nearly 2 months by the damage; however, this did not result in any delay of equipment energization.

The 345-kilovolt transformers furnished by Pennsylvania under schedule No. 1 of invitation No. DS-5780 were also stored at the railhead until installation. The first units were hauled to the powerplant in early July 1964. Because of weight and height restrictions, a special hauling carriage was required for these transformers. The carriage was designed and built by Reliance Trucking Co. These transformers were shipped with a temporary shipping cover welded to the tank. After oil filling, this cover was removed and the upper section of the tank, which provides space for the bushings and current transformers, was welded to the lower part. After the bushings were installed and connected, the oil filling was completed.

The high-voltage bushing draw-leads on three of the nine 345-kilovolt Pennsylvania transformers were too short to reach the bushing terminal. It was therefore necessary to lengthen the leads by cutting them off and splicing on a new piece. Replacement of the leads was not difficult and was considered as a part of the normal assembly of the transformers.

In the final stage of erection of the third transformer on July 30, 1964, a one-half-inch lock washer was accidently dropped into the tank. Many hours of searching did not locate the washer. Since it