(b) Field Problems. --The governor cabinets were stored temporarily at the railhead before being moved to the jobsite. During storage, a considerable amount of moisture collected in the sump tanks. The tanks were cleaned and inspected. The inspection revealed several areas of damaged paint, which were repainted by the completion contractor.

402. Initial Operation of Turbines. During initial operation of generating unit 2, the unit developed a vibration at 100 percent rated speed. Investigation revealed that the problem was caused by some components of the turbine which initiated and sustained a vibration at the natural frequency of the shaft system. After some experimentation the vibration was corrected by injecting compressed air into the space immediately above the runner crown. The air system is designed to provide a constant flow of air by maintaining a steady pressure of 50 pounds per square inch to force the air through a 1/8-inch-diameter orifice. If the station air pressure fails or the needle valve becomes plugged, a low-pressure switch will shut down the unit. If the orifice becomes clogged, a high-pressure switch will cause shutdown.

The corrective action was taken with both turbines. Both generating units were placed in commercial operation on February 14, 1964.

3. Generator Installation

403. General. The two generators at Trinity Powerplant were supplied under the furnish and install invitation No. DS-5422 with General Electric Co., the supplier. See subsection 124(a) for the characteristics of the generator.

The General Electric Co. placed the first material on the jobsite August 28, 1962, and arranged to start preconstruction work. On September 18, work was started on the construction of an office for their use; this was located in the plant storeroom at elevation 1913.00. Work on the units continued from September 18, 1962, until the contract was completed on December 24, 1963.

404. Generating Unit 2. The construction program required that generating unit 2 be assembled first. Work was started on this unit October 1, 1962, and was completed on November 15, 1963.

The first section of the three-section stator for unit 2 was delivered and placed in the erection bay on October 1, 1962, and the last section was delivered on October 4. The stator was completed on November 23, stored temporarily in the unit 1 location, and placed on the unit 2 foundation on April 23, 1963.

The first rotor was delivered on October 9, 1962. Work of stacking the rotor laminations continued until November 24, at which time the contractor discontinued work at Trinity until December 18. During the time the work was shut down, the supplier found that the rotor units had been mismarked and that the spider partially assembled for unit 2 was actually for unit 1. On December 18, the contractor started to disassemble the misstacked unit, completing this work on December 24, 1962. The unit 1 spider was then removed from the erection pedestal and returned to the Redding storage yard until it was required for unit 1.

The second spider section (the one actually for unit 2) was placed on the erection pedestal for stacking of rotor laminations on December 27, 1962. The assembly was completed on April 17, 1963, and placed. in the stator on April 23. The rotor lamina iron was of unusually good quality, all edges had been broken and free of burrs, and sufficient preweighted iron was packed to a bundle to complete two or more layers. These factors were reflected in the case of obtaining a balance on the rotor when the balance runs were made.

Unit 2 was first started on October 21, 1963, and the bearing and balance run was completed on October 27. The dry-out run was started at 12:35 p. m. on October 29, and completed October 31. The General Electric erection engineer released this machine for generation at 9:00 p. m., November 15, 1963. However, power generation from this unit was delayed until February 14, 1964, for correction of an operational problem that developed with the turbine (see sec. 402).

405. Generating Unit 1. Assembly of unit 1 was started on March 26, 1963, at which time the first of the three stator sections was delivered to the erection bay. The assembly of the stator section was completed on April 25, and the foundation for this unit was ready for placement on the stator on May 27. The rotor spider was placed on the rotor erection pedestal May 20; and the stacking of the rotor iron, placing of pole pieces, and all connections were completed on June 26. The rotor was placed in the stator on July 1, 1963. The rotor lamina iron was of the same superior quality as observed for unit 2.

Unit 1 was first started at 10:20 a. m., November 11, 1963, and the bearing and balance run was completed at 3:56 p. m. the same day. The first dry-out run was started at 3:58 p. m., November 11, and completed on November 14.

After the dry-out run was completed, the unit was given the required 28. 6-kilovolt high-potential test. Phases A and B withstood the voltage for the required 1-minute test, but phase C broke down on buildup at 27 kilovolts. The fault was in a factory-placed section of the stator. Being a top coil, a minimum amount of coil had to be removed to make the replacement.

The coil was removed and replaced; and a second dry-out run was started at 12:00 noon December 2, 1963, and completed at 9:00 a. m., December 4. The unit was again given a high-potential test which was satisfactory. The relay operation test, the phasing out test, and the loading test that were delayed when the stator failure occurred were started on December 9. The tests were completed on December 16, 1963, at which time the supplier notified the Government that they were releasing the machine for power generation. The unit was placed in commercial operation on February 14, 1964 (see sec. 402).

The field assembly data for the two generating units are contained in the "Final Construction Report. "2/

406. Test Operating Personnel. The operation of units 1 and 2 at the Trinity Powerplant during all test runs and the 30-day run was performed by personnel provided by the Shasta field division. These operators were on loan from the Coulee Dam Powerplant. The test operations are discussed in sections 404 and 405.

4. Auxiliary Electrical Installations

407. General. As indicated in section 403, the generators at Trinity Powerplant were furnished and installed by a supplier under invitation No. DS-5422. Most other electrical equipment was furnished by the Government and installed by the completion contractor under specifications No. DC-5640, schedule No. 1. A few items were on a furnish and install basis.

The electrical installation work performed by the completion contractor was subcontracted to Del MonteCollins Co. of Hayward, Calif., who employed the D. C. Brown Electric Co. of Redding, Calif., as their field representative. The subcontractor used local electricians to perform all of the installation work, many of whom were inexperienced in heavy industrial electrical work.

The subcontractor started the first work, installation of a temporary power bank, temporary lighting and temporary power wiring, on January 9, 1963. The first electrical construction work creditable to the installation was performed on March 19, 1963, and the contract was completed on December 24, 1963. The contractor used an average crew of eight men including the working foreman. The maximum electrical crew was 12 men, including 1 apprentice electrician.

408. Color Coding of Conductors. All conductors in the powerplant were color coded in conduit; and in the concealed runs where colored insulation was not used, the individual conductors were given a colorcoded adhesive tape wrapping. This wrapping was also used on the conductors in a through-run box, so that no future error would be made in identification of the conductors in the box. The control cable installation required considerable extra field work by the installation engineering staff to prepare a usable cable conductor color code scheme that was adaptable to the Bureau's standards and had a uniform coding for all like installations.

One or two engineers were required in attendance at all times when terminations were being made on the control boards to check the wire code and cable installations.

409. Conduit Installations. Conduit for the second stage of Trinity Powerplant was furnished and installed by the completion contractor under specifications No. DC-5640, with payment made under items 102 to 109, inclusive. The installation consisted of a continuation of the embedded conduits originally installed in the first construction, the additional embedded conduit runs in the two turbine blocks, and some exposed installations throughout the powerplant.

To assist the contractor in conduit installation and to aid in training contractor personnel inexperienced in the work, Bureau personnel prepared a set of inside and outside bend radius templates to check the field bends. No conduits required replacement or shooting after installation. No difficulties were experienced during the swab out of the runs just prior to conductor placement.

With the exception of the two generator neutral grounding cable runs, all of the conduit installed was of galvanized metal conduit, using cast-iron boxes where required. All conduit joints were assembled with extra heavy red-lead paste. All scars in the protective coatings and all cast-iron boxes were given a coat of heavy red glyptal paint.

The generator neutral bus conduit was installed using 3-inch nonmetallic asbestos cement (transite) conduit.

410. Conductors and Cables. All electrical conductors, control cables, power cables, and bare stranded copper grounding cable were furnish and install items. The installation and quality of the conductors and cables are covered in specifications No. DC-5640, and pay schedule items 110 through 132, inclusive.

Individual conductor termination was made by using compression-type terminals on all conductors under No. 8 A. W. G. Above this size solderless terminals were used. Control cables were round packed using a demission fan at the terminal boards. Copious use was made of commercial ties to contain the individual conductors in the packs and cables in groups. All conductors were given a test of resistance to ground and to group conductors prior to final termination.

411. Station Power. The station power installation consisted of a 750-kv. -a. station-service transformer bank (KRB) and a 300-kv. -a. emergency station-service transformer bank (KRC), installed under specifications No. DC-5640, items 150 and 151; the nonsegregated phase busway, installed under schedule No. 1, item 149, of the same specifications; the six alternating-current distribution boards M1A, M2A, MSA, MSB, NSA and LSA and the station switchgear (D1A), installed under the same schedule No. 1, items 140 and 139; and the interconnecting conduits and conductors.

No difficulties were experienced with the installation of major components comprising this system. With the exception of the conduit and conductors, all the components were furnished by the Government under the following purchases:

2/Op. cit. p. 459.

Station-service transformers, invitation No. DS-5579, schedule No. 1, I-T-E Circuit Breaker Co. Nonsegregated phase busways, invitation No. DS-5579, schedule No. 1, H. K. Porter Co.

Six alternating-current distribution boards, invitation No. DS-5644, schedule No. 1, Federal Pacific Electric Co.

Station switchgear, invitation No. DS-5478, Westinghouse Corp.

412. Station Lighting System. The station lighting system, an industrial subdistribution system as the station power system, was installed under specifications No. DC-5640, schedule No. 1, items 155, 156, and 159 through 170, inclusive.

This system consists of the station lighting transformer (KSA), a 112.5-kv. -a. 3-phase 480-208 wye/120volt dry-type distribution transformer, contractor furnished; the LSA distribution board, recessed lighting panels LSA and LSB, and surface-mounted distribution boards LSA and L2A; and the interconnecting conduits and conductors terminating in 282 luminaire units distributed throughout the powerplant interior and transformer deck.

No difficulties were experienced with the installation of the station lighting system.

413. Main Control Boards. These Government-furnished components of the Trinity Powerplant were installed under specifications No. DC-5640, schedule No. 1, and consist of main control board CSA, the unit graphic board CSB, the line graphic board CSC, unit 1 board H1A, unit 2 control board H2A, and the 125-volt direct-current control boards BSA and BSB.

The CSA board required some reconnecting as received, and some repair of damage caused in shipment. In addition, considerable reconnecting of additional equipment installed was required to bring the board into agreement with the latest design drawings.

The unit gage boards H1A and H2A were received with a part of the instruments and relays mounted. The other instruments and relays were furnished by the major equipment suppliers and required installation in the field. Final control design required some modification to these boards.

The governor control cabinet electrical connections were installed as a unit of the unit gage board, as this wiring was interconnected with the H1A and H2A connections.

The main control boards were purchased under the following invitations:

CSA, CSB, CSC, control boards, invitation No. DS-5518, Berry Engineering Co., Long Beach, Miss. H1A, H2A, unit gage boards, invitation No. DS-5697, Wisconsin Electric Mfg. Co., Milwaukee, Wis. A1A, A2A, governor control cabinet, Woodward Governor Co., Rockford, Ill.

BSA, BSB, battery chargers, invitation No. DS-5644, schedule No. 3, A. B. C. Systems, St. Helens, Oreg.

414. Station Battery. The 60-cell 120-volt Gould-type storage battery was installed under specifications No. DC-5640, schedule No. 2. This battery was received several months before its use was required. The battery room and battery charger were available, so the permanent installation was made and the battery was placed on a float charge.

415. Isolated Phase Bus. The Government-furnished isolated phase bus from the two generators to the transformer bank was installed in accordance with specifications No. DC-5640, schedule No. 1, item 148.

The delta-star isolated phase bus assembly, furnished by the H. K. Porter Co., was received in shopassembled grid units, each unit being in the largest size practicable to handle. This permitted the placing of all units exclusive of connections in a period of 8 working days. Only minor difficulties were experienced in the installation. The supply contractor provided an erection engineer for the installation and one Bureau engineer was assigned to inspection of the work. The completed assembly was given a potential test at 37.5 kilovolts prior to connecting to the generators or transformers. The units withstood the high-potential test satisfactorily.

The isolated phase bus was purchased from the H. K. Porter Co. under invitation No. DS-5636.

416. Transformers. The three single-phase, class OA/FOA/FOA, 23, 220/30, 960/38, 700/43,333 kv. -a., 60-cycle transformers, constituting the 230-kilovolt, 13, 200-volt transformer bank at Trinity Powerplant, were installed under specifications No. DC-5640, schedule No. 1.

The transformers were received a year before they were required for installation. The facilities at the Redding, Calif., rail terminal made it impractical to upright the transformers, so they were stored in horizontal position until delivered at the powerplant. Temporary nitrogen gas equipment was installed on the transformers on arrival at Redding, and normal operating gas pressure was maintained on these units until they were placed in position at the powerplant. Weekly readings were taken and a record maintained of the gas pressure throughout the storage period. No damage was indicated; resistance tests of the windings indicated a very high dielectric value.

The detached equipment was stored by the contractor in their Redding storage yard. Parts which were packed in excelsior and paper became water soaked during storage, resulting in damage to the parts. Some required replacement by the contractor; others took extensive cleaning and rehabilitation before they were usable.

The transformers were erected under the direction of the supplier's erection engineer. Other than an unusual cleanup problem, no difficulties were experienced with the installation.

The transformers were placed under vacuum at 27 inches for 36 hours, then filled with transformer oil with a dielectric rating of 25 kilovolts.

These units were purchased under invitation No. DS-5586 from Westinghouse Electric Corp.

417. Switchgear. The two air-blast circuit breakers with the compressor station and piping were installed under specifications No. DC-5640.

The two Canadian-manufactured air-blast circuit breakers and associated air compressors were installed by the contractor under the supervision of the supplier's erection engineer. The units enclosures constructed of welded sheet aluminum were damaged in shipment. The fabricated door hinges had broken requiring replacement by the supplier. Several of the vertical and horizontal welds on the enclosure had cracked, requiring removal and rewelding by the gas arc method. All repairs were made by the supplier, who also replaced some water-damaged parts. After the necessary repairs and replacements, the installation of the two breakers proceeded satisfactorily.

The switchgear was furnished by the Government and purchased under invitation No. DS-5636 from Brown Boveri Corp.

418. Station High-Voltage Strain Bus. The station high-voltage strain bus is used to tie the transformers to the line disconnect. It is relatively small in extent, running from the transformer high-voltage busing to the three-pole manually gang-operated 230-kilovolt disconnect.

This disconnect is equipped with three manually gang-operated line grounding blades and a high-speed manually reset grounding blade on the plan Y side operated by the station differential schemes.

No difficulties or deficiencies were experienced in the installation of this bus.

419. Testing. As wires and cable were installed in the powerplant, they were given a dielectric test with a 1,000-volt megger. The megger readings were taken just prior to the final termination on control circuits and service circuits, including power and lighting, and were rechecked after termination. All readings were taken from conductor to ground and to all other conductors composing the circuit group.

Lighting and power panel circuit breakers were load checked for operation. Control relays were given tests as directed in the Bureau's Power O&M Manual on relay testing and the manufacturer's instruction manual. A copy of these tests is included in the "Final Construction Report. "2/

Regional personnel requested preoperation tests of all relays prior to their being placed in service. A copy of the test schedule is included in the "Final Construction Report. "2/

5. Miscellaneous Mechanical Equipment

420. General. The various mechanical items discussed in the following sections were either furnished and installed by the completion contractor under specifications No. DC-5640 or furnished by the Government and installed by the completion contractor.

421. Turbine Grease System. The centralized lubrication system provided for the turbines was manufactured by Farval Division of Eaton Manufacturing Co. and furnished and installed under specifications No. DC-5640. The centralized lubrication system is provided for lubrication of the wicket gate bushings, gate operating ring, servomotor connections, and gate linkage. The system provided for separate lubrication of the bushings subject to spiral case pressure. This is accomplished by means of directional valves and supply headers. The directional valves divide the supply header from the grease pump into two independent branches for each unit, one branch to supply measured amounts of grease to the bushings subject to spiral case pressure and the other to supply a measured amount of grease to the remaining bushings.

No major problems were encountered during the installation of the lubrication system. After installation, the system was operated through several complete cycles to insure that all component parts operated satisfactorily and all bushings were receiving the proper amount of grease. Several leaks were encountered at the connections to the metering blocks, which were corrected.

422. Sump Pumps. Two electric-motor-driven, vertical-shaft, deep well, turbine-type sump pumps, furnished by the Government, were installed by the completion contractor. These units were manufactured by Layne and Bowler Pump Co. of Los Angeles, Calif. The contractor was allowed to use the sump pumps to unwater the sump and draft tube areas during construction. Subsequently, the contractor used the pumps to unwater the hollow-jet valve stilling basin to permit repairs to the basin.

The tape-operated float switches were adjusted to depress the sump water level to the elevations noted on drawing No. 416-D-835.* Healy-Ruff Co. of St. Paul, Minn. supplied the high-water alarm and sump pump controls. The sump may be dried out for inspection or repair by means of an air-actuated eductor. 2/Op. cit. p. 459.

Not included.

423. Cooling Water Pumps. An automatically controlled cooling water system (sec. 111) is provided for cooling the air in the generator housing. Each unit is provided with a centrifugal pump having a capacity of 1,200 gallons per minute under a 115-foot head. The pump was manufactured by American Marsh, Inc.

The pumps are located in the unwatering gallery and take water from the tailrace through an 8-inch valve and twin strainers. The pumps were furnished by the Government, delivered complete, and were set in place by the completion contractor in December 1963. The pump installation and testing were satisfactory, except that during the operational testing of the generators some difficulty was encountered with the pumps air locking. An investigation revealed that air was being trapped in the return line between the generator air housing and the tailrace elevation, each time the unit was shut down. This problem was overcome by the addition of an air relief valve on each pump.

424. Emergency Cooling Water Pump. One emergency cooling water pump is provided for both units. The emergency pump is provided with manual control only. The pump was manufactured by American Marsh, Inc., supplied by the Government, and installed and tested by the completion contractor. The pump was installed and tested in February 1963. No problems were encountered during the installation or the testing.

425. Diverting Valves. The diverting valves were manufactured by Minneapolis Honeywell Co. and are a three-way, constant-flow, diaphragm-operated type with a pilot control to maintain a nearly constant air temperature in the generator air housing by controlling the amount of water circulated through the cooling system. Installing, adjusting, and testing of the valves was done by the completion contractor. During the testing it was discovered that the flow of water past the valve rotated the adjustment rod. This condition was corrected by the addition of a locking nut. No other problems were encountered.

426. Air Compressors and Receivers. Three air compressors were furnished by the Government and installed by the completion contractor. One 65-c. f. m. and one 375-c. f. m. air compressor (sec. 115), were manufactured by the Pennsylvania Pump and Compressor Co. of Easton, Pa. These two motor-driven compressors supply air to the generator brakes and for general service. A 20-c. f. m. air compressor manufactured by the Gardner-Denver Corp., is used as an auxiliary to the air circuit breaker system. The governor oil tanks are charged with nitrogen. Each compressor was run for over an hour to check the noload operation. The pressure was gradually increased to maximum operating pressure and the units were run until all bearing temperatures leveled off. At this point the manual and automatic control operations were checked and adjusted. The compressors were then ready for operational testing. Operational testing began after the piping was tested on October 1, 1963.

The air receivers were manufactured by Richmond Engineering Co. of Denver, Colo. The compressors and receivers were painted in accordance with specifications No. DC-5640.

427. Fire-Protection System. The fire-protection system at Trinity Powerplant is described in sections 116 through 119. The following additional information is given on the system.

The fixed carbon dioxide system consists of a total of forty-one 75-pound cylinders. Seventeen of these cylinders are spares. Each rack has an overhead beam and trolley from which a scale may be hung to test weigh the cylinders.

The system for the generator air housings consists of 13 cylinders in the first charge and 4 cylinders in the delayed charge. The discharge may be initiated automatically by a temperature-sensitive element in the air housings, manually by an electrical switch on the side of the air housing, or manually at the cylinders without the use of electricity. If the automatic or electrical-manual discharge is activated, the charge is directed to the proper air housing by weight-operated valves released when the circuit is energized. Energizing the circuit starts the timer for release of the delayed charge. When the system is discharged manually at the tanks, the weight-operated valves must first be manually operated to direct the charge to the proper air housing. The delayed charge would also require manual discharge; initially this delay is set

at 45 minutes.

The carbon dioxide charge to the oil purifier room may be actuated automatically after flow through the sprinkler system operates the time delay, by manual-electrical control from a remote switch, or by manual control at the cylinders without electrical current. The fire doors to the oil purifying room will close when the heat melts à fusible link in the weight line holding the door open, or when the electrical circuit is energized to initiate the carbon dioxide discharge.

Three 100-pound wheeled cylinders are provided for local usage. One cylinder is stored on each of the three decks. Five- and fifteen-pound cylinders are provided for hand usage.

428. Piping and Fittings. The pipe installation work performed by the completion contractor began with the lower elevation drains in March of 1962. The progress of installation was generally uneventful.

Several sections of piezometer pipe had to be removed and reinstalled because of unsatisfactory initial installation. The curved sections of cooling water piping in the air housing bases were very difficult to install; and this difficulty was accentuated because of a need to loosen each flange and add a fiber insulator after the original installation was found to be lacking these insulators.

After testing the air piping with water, several valves trapped pockets of water which would not drain and caused difficulty in purging the system of the water. When the hypochlorinator was installed, the air compressor cooling water system became a chlorinated water supply. This caused an unnecessary drain on the chlorine solution.