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City of Thorne Bay Utility Renovation Study Electrical System 1984
City of Thorne Bay Utility Renovation Study Electrical Sysiem P.O. BOX 432 THORNE BAY, AK 99950 MARCH 1984 ELECTRICAL SYSTEM I. Introduction A. History B. Objective II. Condition & Analysis Report A. Existing Facilities' Condition Generators Generator Control Generator Building Plant Substation Distribution System Other Utilities on Poles NUFWDH- III. Goals & Recommendations A. Immediate Improvements 1. Pole Replacement 2. Unused Line 3. Distribution Lines 4. Metering 5. Transformer Station Building 6. Operation B. Short Term Improvements 1. Distribution System 2. Generation System C. Long Term Needs 1. Local & Prince of Wales Island 2. Service to South Thorne Bay/Tolsoti Area 3. Distribution System IV. Cost Estimates V. Prioritized Needs A. Immediate Needs B. Short Term Needs C. Long Term Needs Summary Appendix A, Photos Appendix B, Maps Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page ANUUNUY wn WWWND DY nN ~ Nw ooo 9 11 11 12 Soe Ow’ Al B. ELECTRICAL SYSTEM Introduction A. History On August 13, 1982, the State of Alaska approved incorporation of Thorne Bay as a second-class city. This acceptance of Thorne Bay into the com- munity of Alaska cities was the culmination of an orderly and logical chain of events. The City commenced life in 1961 and 1962 as the world's largest logging camp, owned and built by Ketchikan Pulp Com- pany. During the following twenty-odd years, the logging camp began to mature as a transportation, communication, and service center for the eastern side of Prince of Wales Island. Adding to this, the advent of decentralization of the Louisiana-Pacific Corp. logging operation brought the opportunity and need for logical progression into the status of a City of the State of Alaska. As stated above, the City was built and began life in 1961 and 1962 as a logging camp. In addition to the usual bunkhouses and other buildings, homes were built for the salaried employees and permanent work force. Utilities were constructed in the most expeditious manner, i.e. sewer and water service lines and mains often occupied a common trench under the homes and buildings, with power lines being directly over the same buildings. Materials used were often not the best available, and construction was often not to State and federal building codes. So today, a considerable portion of the public utility infrastructure is at, or rapidly approaching, planned obsolescence and unable to ful- fill the needs of a modern Alaskan city. In addition, public safety, health, and welfare is endangered on a daily basis. Objective The City of Thorne Bay has retained the firm of Shaner Engineering to make an independent review and evaluation of the total electric system. Part one of the review will center on the condition, operation, and capacity of the electric system in respect to the City's desire to correct existing deficiencies, improve operations, and meet future growth of the community. The second section of the report will outline the goals of the City in relation to the distribution system and generator system, future growth, and efficient operations. Recommendations will be made on problem areas. The completed study will chart a course for capital works expenditures by the City of Thorne Bay to upgrade the infrastructure in a planned, orderly fashion. Cost estimates will be made, and prioritized needs will be listed to address the most critical issues first. eae LES ELECTRICAL SYSTEM Condition & Analysis Report (As of February 10, 1984) A. Existing Facilities' Condition 1. Ds Generators The powerplant consists of three diesel-fueled Caterpillar engine generator sets, producing 480 volt, three-phase. a. 500KW Generator At the present time, this generator is used as backup/standby. From records furnished by the City, it currently has about 27,000 hours running time; 9,800 hours since last overhauled in July 1980. b. 300KW Generator This generator is the one currently being used to provide power for the entire system. Records show about 9,624 hours since the last rebuild, for a total of 31,300 hours running time. The rebuild took place on August 7, 1982, which involved reboring. From information received from Mr. Fox, the maintenance con- tractor, this engine burns oil, and some seals and the injectors leak. To make any repairs would require shutdown. c. 150KW Generator This generator is currently being used for emergency standy, and has approximtaely 18,000 hours running time. Generator Control It appears that all starting and control is now manual, and that startup after a power failure requires considerable time, and at least two people. To run more than one generator at one time is difficult from the standpoint of balancing, phasing, and voltage regulation. Instantaneous metering appears to be adequate to show total and City consumption. Generator Building The structure consists of a wood-frame building on a concrete slab, with no interior finish. It is poorly lighted, and although the working space in front of the panels is above minimum of the National Electric Safety Code (NES), the adjacent generators cause congestion during maintenance. The building contains air compres- sors not being used by the City, requiring access for other than authorized City personnel. Il. ELECTRICAL SYSTEM Condition & Analysis Report A. Existing Facilities' Condition (cont'd. ) 4. 5. Plant Substation The facility consists of three PCB oil-filled 200KVA, single-phase, 480V primary to 2300V secondary transformers, pad mount, connected delta-delta. They are fed from the generator bus with 3/500mcm conductors in each of two 3" conduits. The primary bbus is fused at 50 amps feeding the City. Also connected to the primary is an underground line to the Forest Service. Connected ahead of the substation at the 480V bus is an underground line to the L-P shops. Distribution System a. 2300 Volt System Overhead three-phase line from the plant substation to the City substation consists of three #2/0 aluminum conductors at the top of the poles. It terminates in the City substation building feeding from an overhead open-wire bus to six 100KVA 2300 volt primary, 480 volt secondary, single-phase PCB oil-filled trans- formers. Primary fusing and disconnecting means is provided at the plant substation. b. 480 Volt System Eight different services in the City substation building feeds the overhead 480 volt distribution lines that services all of the City. These lines consist of various sizes of aluminum con- ductors, both three-phase and single-phase. The various homes and commercial users are serviced from the overhead lines with service drops fed from pole-mounted 480-120/240 volt dry-type transformers. c. Condition 1. Poles Many of the poles are the original system which apparently have been in place for over 20 years. They are untreated native cedar, and are showing considerable rot, checking, and weathering--both underground and overhead. Some are located such that they cannot be reached by aerial ladder, and are in such poor condition that it makes climbing ex- tremely dangerous, and a violation of NES Code Rule 236. The separation between conductors of different systems on the poles in general violate Rule 235. Many of the cross- arms have deteriorated to the extent that they, too, should be replaced. Il. ELECTRICAL SYSTEM Condition & Analysis Report A. Existing Facilities' Condition Se c. 2s 9 4. Distribution System Condition (cont'd. ) Distribution Lines Both 2300 volt and 480 volt systems are aluminum conductors with numerous splices and connections made with hand- tightened connectors, making solid continuity difficult, which could result in line loss. The size of conductors at all locations may not be adequate to service the loads that are presently connected. Many of the lines between poles, as well as service drops, pass over, or are too close, to buildings--which is a violation of Rule 234 of the NES Code. A minimum of 8' clearance over buildings for voltage up to 60 volts should be maintained. The best practice is to avoid passing over buildings. The original layout of housing and streets virtually precludes uses of overhead systems in the older sections of town. Generator Building The lighting is a safety hazard and below the minimums of the NES Code Rule 111. The control and electric panels should be in a separate room, secured, away from the generators to isolate from the noise and vibration, and prevent access by unauthorized personnel. Foregin piping and equipment not necessary for the operation of the gener- ating equipment should be removed. The batteries present hazards to personnel, and are in voilation of Section 14 of the NES Code with regard to location, racks, illumination, and service. Transformer Station Building This entire facility should be eliminated as soon as it is practical. The transformers are PCB oil-filled, the clearances between wires, and in and around equipment are in violation of both the NES Code, and the National Electric Code. To gain access and work on some of the 480 volt equipment, it is necessary to go through, and be too close to, the 2300 volt wires. The lighting is inadequate and servicing is up through the 480 and 2300 volt wires. ELECTRICAL SYSTEM II. Condition & Analysis Report A. Existing Facilities' Condition (cont'd. ) 6. Other Utilities on Poles Located on the above pole line are conductors for telephone, tele- vision, intercom, and fire alarm--some of which are no longer in use. At many of the poles, the number of terminations make it very difficult to climb through, or get to the power distribution system. III. Goals & Recommendations A. Immediate Improvements 1. 4. Pole Replacement Survey and test all poles for rot, checking, size and location. Replace and/or relocate with new poles. Replace any arms and hard- ware that are inadequate or unsafe. Unused Line Remove any wires or cables of other utilities that are no longer in use. Relocate others, if necessary, to provide adequate climbing space. Distribution Lines Survey and size all overhead lines. Replace all split bolt-type connections with compression type of correct size, and installed with proper tools. Check service drops from poles to customer and replace and/or re-terminate as necessary. Metering It appears that there are losses, and becuase of incomplete metering, it is difficult to tell the source. Currently, Thorne Bay generates about 7.5KWH (Kilowatt Hours) per gallon of diesel fuel. The figure should be in the range of 9 to 12KWH per gallon. However, the figure has improved from 3.5KWH in early 1982. a. Plant Power Output Install recording wattthour meter to measure total output of generating equipment. This will allow for verification of power production and comparison with fuel consumption as well as with total individual customer usage. Mig III. A. ELECTRICAL SYSTEM Goals & Recommendations Immediate Improvements 4. a 6. Metering (cont'd.) b. Customer Consumption Continue to install individual watthour meters at all services to all customers. City street lights that are on fixture photo- electric eye control can be estimated. c. Demand Metering For customers who may have a significant amount of large motors, or other loads, it may be desirable to install demand meters, because of the added cost of providing larger lines, trans- formers, and services. d. Reactive Metering For customers who may have a significant amount of inductive (motor) loads, it may be desirable to install additional reactive meters to measure this power consumption. e. Heat Loss The heat loss from the generators is being recaptured and used for heating the LPK shops. This energy should be metered and sold to the user. Transformer Station Building The eventual conversion to a system distribution voltage of 12.47KV will eliminate the need of this facility. In the meantime, the facility should be made safer for personnel by installing guards and protection around live conductors and equipment, relocate some equipment to make it more accessible, and revise lighting to meet codes. Operation An electric utility is a very technical business and very costly to operate and maintain. Trained and certified operators and mainte- nance men are needed for the continuous operation for the diesel generators, the control room, and the distribution system. Due to the dangerous nature of electrical work, it is assumed that the City has both a good general liability insurance policy, as well as workmen's compensation insurance coverage for all electrical and other utility workers. It is in the City's interest to have trained, certified, and adequately compensated operators and main- tenance workers (or contractors) handling the electric system. Z6= Ill. B. 1. ELECTRICAL SYSTEM Goals & Recommendations Short Term Improvements Distribution System A more common and practical distribution voltage is 12.47KV. This will require the installation of new transformers at the generation facilities, which will eliminate the need of the substation in the building on the hill (i.e. Section A, Paragraph 5 above). Although more technically qualified personnel are required for installation and servicing, the advantages of less voltage drop, fewer problems, and greater flexibility should over-shadow any disadvantages. Com- bined purchasing sharing of emergency supplies with other utilities at 12.47KV would keep costs down, and help eliminate down time in emergencies. The relative merits of overhead and underground dis- tributions are discussed here, with the financial aspect covered in Section IV, Analysis. a. Overhead The advantages of the overhead system is primarily one of construction cost. Much of the newer overhead lines and poles are usable in the 12.47KV system, with changes in insulators, clearances, and conductor sizes. All of the old, untreated poles should be replaced as well as relocating any line that passes over buildings or any poles that are inaccessible. b. Underground The underground system is more costly to install initially, but is less expensive in maintenance, servicing, and upkeep. The first phase of installation could be in the Rainy Lane area, with the duct bank being installed in conjunction with, and as a part of, the sewer and water project. Four inch duct is a recommended size. Generation System Common generation voltages are 480V, 2300V, and 4160V. Since the existing generators are 480V, it is recommended to stay with this voltage for additional generators. a. Judging fromthe projected growth over the next five years, an additional 450KW generator should be installed immediately to parallel with the existing, and another 450KW should be installed for backup and standby. b. Automatic Switching To improve system reliability, and reduce emergency service costs, each generator should be provided with its individual switching, metering, and monitoring cubicle that will control Ug TT. ELECTRICAL SYSTEM Goals & Recommendations B. Short Term Improvements 2. Generation System b. Automatic Switching (cont'd. ) the use of the generator. Additionally, a "demand" section should be installed to sense the changes in load demands, and to cause the starting or stopping of a generator efficiently as the load changes. Also, centralized control of load shedding, as well as startup after an outage, will improve efficiency, reduce down time, and cut service costs. This could be handled initially on a manual basis, converting later to automatic operation. C. Long Term Needs Ais Local & Prince of Wales Island The long term goal should be efficient and safe production and delivery of power to fill the needs of the residents, businesses, and public bodies in the City of Thorne Bay. It may be that the Alaska Power Authority's Black Bear hydroelectric project will, in time, be available to fill the long term need. Or perhaps another form of power may grid Prince of Wales Island, and serve the various communities. Service to South Thorne Bay/Tolstoi Area Service to South Thorne Bay and the Tolstoi Bay area must be ad- dressed shortly. With the advent of a road connection to these areas this year, demands for all power will follow immediately. A power line from the existing City of Thorne Bay generating plant to above-mentioned newly opening subdivisions should be designed and constructed. Power transmission and distribution must be a part of any comprehensive study and planning effort for the Tolstoi port project. Distribution System The distribution and transmission systems for the remainder of Thorne Bay proper should be placed underground or overhead where feasible. These sytems shouls be placed permanently for safety, efficiency, and aesthetic values. At such time that the water and sewer utility sytems in the newer sections of town approach the end of their useful life. Conversion to an underground electrical util- ity should normally be completed as part of the overall system. Iv.- ELECTRICAL SYSTEM Cost Estimates A. Design & Contruct Distribution System $150,000.00 Emergency B. Generation (2) 200,000.00 F. Distribution System, Remainder of Thorne Bay C. Design & Construct Generator ] Building ] ]To Be Determined D. 12.47KV Transmission Lines (Including ] Transformers, Controls, etc.) ] In Phases III ] E. Rainy Lane Distribution System ] & IV Of This (Permanent Underground) ] ] Contract ] J Proper (Permanent Underground) Prioritized Needs A. Immediate Needs hs Distribution System Emergency Existing hazards in the poles and pole lines in the Rainy Lane neighborhood, and Spruce Lane/Hemlock Loop neighborhood neces- sitate immediate replacement and/or repair. A design and construct costs of $150,000.00 is estimated, to include: schematic design, approximately 25 new poles, down guys and anchors, relocated service drops, new conductors and connectors where needed, and removal of existing poles and equipment that are replaced. This is based on utilizing the City's existing "pole yard" of native cedar trees, and other materials that might be available for the Rainy Lane area. The Spruce Lane/Hemlock Loop area would get new treated poles and better materials. This does not replace all of the power lines in the two areas--only those that are in the worst condition. Hope- fully, this would extend the system life for two to five years in the Rainy Lane area, and ten to fifteen years in the Spruce Lane/ Hemlock Loop area. This does not include costs of moving or improving other systems (like telephone) that are on the City poles. Generation (Alternate 1, Existing Building) Proceed with the design, bidding, purchasing, and installation of at least one more generator, to be connected to the existing sub- station and distribution system. It is important that this be done with some long term planning in mind. One alternative would be as shown in the floor plan sketch of Figure 1. New generators would be installed in the building attached to the present generator loca- -9- V. A. 2. ELECTRICAL SYSTEM Prioritized Needs Immediate Needs Generation (Alternative 1, Existing Building [cont'd.]) tion, allowing continuous operation. The new control panels would be located in the existing building where the battery chargers are now located. The battery chargers would be relocated as shown and a new room built to house the batteries to conform to NES Cade, Section 14. Fuel storage could be where the existing tank is, in the area designated "Future Expansion." Another recommendation is that fuel should be piped directly (and metered) from the fuel farm. When the generators are tested and ready for use, they could be phased in and assume the load, allowing for the removal of the worn out 5SOOKW and 300KW sets, at such time they are "run out." The 150KW generator could be moved to the new generator room for standby use, or it could be traded in. With complete removal of all equip- ment from the existing generator building, it would then be ready for use as a Control Room, and a place for future 12.47KV trans- formers. A cost of $65,000.00 is estimated to include: move radi- ators and fuel tanks from building, pour new slab and generator foundation, sheetrock interior, connect power to existing bus, building battery room and control room, ecisting equipment, including schematic design. (This does not include engineering management, inspection and supervision, nor does it include trans- formers, generators, control panels, or centralized or automatic control.) It is estimated that the 450KW generators and control panels will cost approximately $100,000.00 each. Generation (Alternative 2, Using LPK Shop Building) At the time of writing this study, it appears that the adjacent Louisiana-Pacific metal shop building, 40 feet x 140 feet, may come under City ownership. Therefore, under direction of the Utility Renovation Committee, a proposed power plant facility schematic design was prepared (see Alternate #2, page 10c).- The building will need extensive foundation, siding, and roof repair, plus installation of a concrete floor (25% of the existing floor is concrete). However, the building appears structurally sound, and is well-sited. Most of the above repairs could be done by local Thorne Bay contractors. The larger building would give ample room for future expansion, and could be made a safe, spacious, power generating facility. If the building becomes available, it is recommended that a realistic cost appraisal be made. -10= Al | COMPA. WASH. PANELS S00KN 480. 3500 KW/ OLD WASHII/G TOA CONTROL PAWELS GENERATOR “S £lee TRUCE EXISTING POWER PLANT FACILITY V7! OF THORNE GA! ALASKA SCALE: ("10 FF AIMALCH, 1984 -Page 10a- 12.47 kV FEED Foarr S FOOT UE ‘eI EX PAMS(OM $50 (50, 1&4 GEW. GEN. | - | \ 2 24 [Nw J PROPOSED POONER PLANT FACILITY OV7Y OF THORNE BAK MMLASKA SCALE: (1° *104£7- AIP CCH, (IBF -Page 10b- Zot GAL Overhead 77 + ¥ Concres Ne “we 9 Remote Kad ator fS5OKW 450 KW Ger. Gert. ae . -_ EXISAG seis Lovicrere- 4foor Work Shep | Control Koom \ | Spare ¥l Barkels %| | . ee | a \ satire Expa7so—_. w Sa teAgear y) a J “a ——— + ——— — 8/2 -page LO. 0 > V. ELECTRICAL SYSTEM Prioritized Needs A. Cs Immediate Needs (cont'd. ) 4. Operation Review training and certification of operating and maintenance workers and contractors. Ensure that State laws and regulations are met. Ensure that adequate insurance (i.e. general liability and workmen's compensation) is in force, and that reasonable length employments contracts are made. Short Term Needs a Distribution In the Rainy Lane neighborhood, and Spruce Lane/Hemlock Loop neigh- borhood, take from the emergency repaired schedule status to perma- nent underground status in Rainy Lane neighborhood, and a perma- nent overhead line status in the Spruce Lane/Hemlock Loop neighbor- hood. Generator Automatic control is desirable at some future date. We have decided to go manual at this time. Long Term Needs 1. Plan service to South Thorne Bay, LPK Sort Yard, and the Tolstoi Bay areas. Cooperate with Alaska Power Authority's Black Bear hydroelectric project. Distribution system and transmission systems placed underground. mas ELECTRICAL SYSTEM Summary As this report is being written, two 450KW generators are being purchased to replace the existing, worn out 5OOKW and 300KW generators. The generator building and control facilities' problems should be concurrently met so as to ensure proper installation and use of these new generators. The distribution system emergency that exists in the Rainy Lane neighborhood, and the Spruce Lane/Hemlock Loop neighborhood must be addressed immediately because of the potential, to both citizens and the line maintenance workers, of fatal hazards. The City has a very high liability here. Arrangements must be made for training/hiring a generator operator, and a backup operator. A proper maintenance schedule for both generator facilities and distribution systems must be made. For the continued health and welfare of the citizens of the City of Thorne Bay, the electrical system needs, as expressed in this report, must be met. To date, by dint of sweat and devotion to the aging plant and distribution lines, the system has been kept in operation. With the purchase of the two new generators, some emergency line repairs, proper generator control features, attention to the personnel needs, and commencing needed capital improvements, the older portions of the system will begin to take on a new life. The newer parts of the electrical system should continue giving good service for many years. = 2 ELECTRICAL SYSTEM APPENDIX A POLE #42, RAINY LANE AREA HAZARDS: VIOLATIONS: Restricted Climbing 1. Climbing Space Space 2. Separations & Spacings Rotten 3. Isolation & Overload Poor Wire Condition Protection ELECTRICAL (STEM APPENDIX A POWER HOUSE--CONTROL EQUIPMENT Control panels & breaker cabinet of old generator not being used, and exposed 480 Volt wiring. Limited access & work area. ELECTRICAL SYSTEM APPENDIX A 2300 VOLT SERVICE POLE AND LINE Connections at wire bus should be replaced with com- pression type. Wires between cutouts and top line are too close together without support and could cause outage by swinging together. Aerial line deadened with single arm. It should be double arm to provide more strength. No anchor on pole could cause too much strain. ELECTRICAL SYSTEM APPENDIX A 2300 VOLT SUBSTATION 1. PCB oil-filled transformers should be replaced. 2. Conduit, cutout and wire system feeding Forest Service could be source of problems in providing continuous ser- vice. 3. Platform adjacent to transformers should be replaced. ve «a Ne ELECTRICAL SYSTEM APPENDIX A 2300-480 VOLT TRANSFORMER BUILDING PCB oil-filled transformers should be replaced. ELECTRICAL SYSTEM APPENDIX A 2300-480 VOLT TRANSFORMER BUILDENG Overhead wires at both 2300 Volt and 480 Volt are within 6 1/2 feet from floor. Working space around 2300 Volt conductors is below mini- mum code. Wooden Supports of open conductors may not be adequate for weight. Open wires not suitably protected. ELECTRICAL SYSTEM APPENDIX A POWER HOUSE-- BATTERIES Located between generators, restricting service. Battery cables on floor and subject to damage. Batteries located too close to generator, subject to extreme vibration. Water Treatment Plant = 100 ° 200 400 ee Scale I = 200' is c f & Shop 8 a Gp f 3 \ o ¢ j \ t Tr = S z . / cat - Se fs & ; ' re a Sec % £ is ae sone al oy poe} %, ‘ re © ef + pL | oa U.S. Forest Service Admirfstrative Area ~“_, 7 oa oe Z , > oe - : . . L_ / Administration Office <}49 1a a ae: = ~~“ Bio ae —— Tata | 8 y Set ns ale ol-— s wo ale ee 983 - one" "dergroung) —. S [mm .- Cn. ISS fre = Cs Generato »/ ~ /~™ / / ae iff : SQ 4 / Louisana 7 Shops Area / Up lo | @ a 480V, 1962 School __ Generating I~ Building THOR fe BAY LEGEND Existing power lines, overhead unless otherwise noted, _ Indicating voltage and date of construction. Proposed power conduit (Underground ) 4 Proposed power {Overhead} == Bap en ee ee ee Te es een B ELECTRICAL Ne LISTAIBUTION SVSTEN \ CU7t OF THORME BAK, ALASKA BY: SHAME. LVGIMEER IG PO BOK F352 THORME BA LASKA ATALEL, / 9EF. SHEET. Te