This handbook provides information regarding current Clark Public Utilities standards, diagrams and specifications for approved high voltage contractors

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Table of Contents(PAGE 2) TABLE OF CONTENTS PAGE Trenching 3 Cable Reel Handling & Cable Pulling Requirements 8 Single-Phase Transformer Set 13 Secondary Pedestal 36 Lighting 42 Metering 45 Three-Phase Transformer Set 55 Open Wye-Open Delta Padmount Installation 60 Single-Phase J-Box 62 Three-Phase J-Box 642
Trenching50PAGE 351 50PAGE 451 50PAGE 551 50PAGE 651 50PAGE 7513-7
Cable Reel Handling & Cable Pulling Requirements50PAGE 851 50PAGE 951 50PAGE 1051 50PAGE 1151 50PAGE 1251 50PAGE 13518-13
Single-Phase Transformer Set50PAGE 1451 50PAGE 1551 50PAGE 1651 50PAGE 1751 50PAGE 1851 50PAGE 1951 50PAGE 2051 50PAGE 2151 50PAGE 2251 50PAGE 2351 50PAGE 2451 50PAGE 2551 50PAGE 2651 50PAGE 2751 50PAGE 2851 50PAGE 2951 Clark Public Utilities — Commercial Electric Service Handbook Chapter 3: Commercial Underground Services / January 2011 17 Transformer location and access Underground electrical facilities must be readily accessible by the util ity during construction and for future operation and maintenance. The area around padmounted electrical equipment must provide a clear and level working space and remain free from obstructions such as landscaping, poles, retaining walls, structures, fences, etc. All transformers and padmounted equipment are to be located:  Within 10 feet of a drivable surface but not closer than 5 feet (Figure 3).  With the front of the equipment (door and lock side) facing toward the drivable surface.  With the transformer pad parallel to the edge of the drivable surface.  Allowing 10 feet of clearance in front and 3 feet from the back and side s of the equipment(Figure 3).  At least 2 feet from a sidewalk for pedestrian safety. Figure 3Commercial padmounted transformer location and access drivable surface VIEW FROM ABOVE curb transformer 3 ft. minimum of clear working space from back and sides 5 ft. minimum to 10 ft. maximum of clear working space from drivable surface to front of transformer pad edge of transformer pad position transformer with door and lock facing the drivable surface 2 ft. minimum of clear working space from a sidewalk to front of transformer pad sidewalk door and lock 50PAGE 3051 Clark Public Utilities — Commercial Electric Service Handbook 18Chapter 3: Commercial Underground Services / January 2011 Transformer safety clearances Clearances from padmounted transformers to structures are measured from the nearest metal portion of the transformer to the structure or any overhang. The clearance from a building is 10 feet if the building has combustible walls, and 3 feet if the building has non-combustible walls as shown in Figure 4. Table 4 provides additional safety clearances that apply to any oil-lled electr ical equipment. non-combustible structure and roofcombustible structure and roof 20 ft. 10 ft. 10 ft. minimum operable window or other opening door or other opening gas meter transformer transformer transformer hydrant fuel dispensing facilities fire escape 10 ft. 10 ft. 10 ft. 10 ft.15 ft. 6 ft. fuel storage 3 ft. min. 3 ft. Figure 4Commercial padmounted transformer minimum safety clearances 50PAGE 3151 Clark Public Utilities — Commercial Electric Service Handbook 20Chapter 3: Commercial Underground Services / January 2011  If the distance between the corner posts exceeds 5 feet, a removable center post is required (Figure 5).  If a removable center post is installed, the threaded joint requires treatment with an anti-seizing agent.  Paint exposed section of post “trafc yellow.” Figure 5Guard post (bollard) installation for commercial transformers FRONT VIEW VIEW FROM ABOVE 3 ft. minimum 18 in. minimum on 45° removable center post,as required 2 ft. domed concrete FINAL GRADE 4 in. galvanized/steel pipe, concrete filled 4 in. galvanized/steel pipe, concrete filled concrete fill removable center post, as required coupling do not fill center post with concrete edge of transformer pad commercial transformer door and lock edge of transformer NOTE: Additional guard posts may be required at back and sides of transformer. 50PAGE 3251 50PAGE 3351 50PAGE 3451 50PAGE 355114-35
Secondary Pedestal & BDR50PAGE 3651 50PAGE 3751 50PAGE 3851 50PAGE 395136-41
Lighting50PAGE 4251 50PAGE 4351 50PAGE 445142-44
Metering70'70' 100' 140' 400' 200' 160' 200' 300' 150' #10 W IRE @ .009989 OHM PER 10' 75' 80' 100' 60' 200' 0.5374 0.3386 0.418 0.4974 0.458 0.4206 0.1808 0.2108 0.2208 0.2608 0.461 0.1708 0.1408 0.1808 0.2208 0.243 120' 250' 0.002 0.3786 0.17216 0.2198 0.28332 0.009 0.05 DIS TA NCE CHA RT SOLID STATE METER TO TA L W IR E DIS TA NCE #12 W IRE @ .01588 OHM PER 10' 0.002 < MIS C> ADD ELECTRICAL M E CHA NICA L 150' 0.009 < TE S T S W > 0.132 0.1798 100' 125' 35' 50' 0.01 CT TO METER DIS TA NCE Meter Department Pre-Made Wire Bundles All are solid copper wire 1 ∅ Potentials #14 gauge B lack, G reen, W hite Currents #12 gauge Blue, Yellow, Brown 3∅ Potentials #14 gauge Black, Green, W hite, Orange Currents #12 gauge Blue, Yellow, Brown, Red Note: Maximum distance for #12 current wire is 35 feet one way to meet burden of 0.2 on rating factor 4 C.T.’s. For C.T. conduit run over 35 feet use #10 current wire to a maximum of 60 feet for a burden of 0.2. If a longer conduit run than 60 feet is unavoidable – see meter department for C.T. and burden chart’s and C.T. sizing. 50PAGE 4551 50PAGE 4651 50PAGE 4751 Clark Public Utilities Metering Requirements Commercial Applications Circle AW part numbers are for cross reference only. All Commercial current transformer ca binets shall have hinged doors. CURRENT TRANSFORMER CABINET DIMENSIONS, CT MOUNTING BASE See EUSERC Spec – 328B & 329B Over 800 Amps Switchgear Required Maximum wire size 600 MCM per lug or parallel per EUSERC SPEC. & UL label Rev 4: Changed blocks with a *. Source Voltage Ampacity Reference Circle AW Part Number Meter Diagram Numbers Number of Terminals Bypass Provision Required Test Switch Required 120 Volts 1 ∅ 2 Wire 0-100 Amps U121314* MD01 4 Yes No 120/240Volt 1 ∅ 3Wire 0-200 Amps U264 MD02 4 Yes No 120/240Volt 1 ∅ 3Wire 0-400 Amps 324N, 324NF MD03 4 Yes No 120/240Volt 1 ∅ 3Wire Over 200 Amps 12146 MD10 MD11 6 No Yes 240/480Volt 1 ∅ 3Wire 0-200 Amps 124TB MD02 MD05 Dmd 4 Yes No 240/480Volt 1 ∅ 3Wire Over 200 Amps 12146 MD10 MD11 6 No Yes 120/208Volt 3Wire Network 0-200 Amps 125TB MD04 5 Yes No 120/208Volt 3Wire Network Over 200 Amps 12148 MD12 8 No Yes 240Volt 3 ∅ 3Wire Delta 0-200 Amps 125TB MD06 5 Yes No 120/208Volt 3 ∅ 4Wire Wye 0-200 Amps 127TB MD07 7 Yes No 120/208Volt 3 ∅ 4Wire Wye Over 200 Amps 121413 MD13 13 No Yes 240/120Volt 3 ∅ 4Wire Delta 0-200 Amps 127TB MD08 7 Yes No 240/120Volt 3 ∅ 4Wire Delta Over 200 Amps 121413 MD14 13 No Yes 277/480Volt 3 ∅ 4Wire Wye 0-200 Amps 127TB MD07 7 Yes No 277/480Volt 3 ∅ 4Wire Wye Over 200 Amps 121413 MD13 13 No Yes 480Volt 3 ∅ 3Wire Delta 0-200 Amps 125TB MD06 5 Yes No 480Volt 3 ∅ 3Wire Delta Over 200 Amps 12148 MD12 8 No Yes Amperes Dimensions Circle AW or Equivalent 200 Amps- 400 Amps 1∅ 24” X 30” X 11” 6019-HAL (LUG LUG) 401 Amps- 800 Amps 1∅ 30” X 36” X 11” 6019-HEL (LUG LUG) 200 Amps- 400 Amps 3∅ 30” X 36” X 11” 6019-HAL or 6067-HAL 401 Amps- 800 Amps 3∅ 36” X 48” X 11” 6019-HEL or 6067-HEEL 50PAGE 4851 Clark Public Utilities Metering Requirements Residential Applications Circle AW part numbers are for cross reference only. CURRENT TRANSFORMER CABINET DIMENSIONS, CT MOUNTING BASE * Optional Notes: 1. CT Metering for 200- 400 Amp panels required pre-approval from Clark Public Utilities 2. All CT cans shall be mounted outside. Rev 2: Add optional CT cabinet dimensions and notes. Source Voltage Ampacity Reference Circle AW Part Number Meter Diagram Numbers Number of Terminals Bypass Provision Required Test Switch Required 120 Volts 1 ∅ 2 Wire 0-100 Amps 011 MD01 4 No No 120/240Volt 1 ∅ 3Wire 0-200 Amps 204, U204 MD02 4 No No 120/240Volt 1 ∅ 3Wire 0-400 Amps 324N, 324NF MD03 4 Yes No 120/240Volt 1 ∅ 3Wire Over 400 Amps UO11, 011, 925 or 926 MD09 MD11A 5 or 6 No No Amperes Dimensions Circle AW or Equivalent 200 Amps- 400 Amps 1∅ Window 24”h X 32”w X 9”d PED *401 Amps- 800 Amps 1∅ Buss Mt. 24”h X 30”w X 11”d hinged door 6019-HAL (LUG LUG) 200 Amps- 400 Amps 3 ∅ Window 30”h X 36”w X 11”d PED *401 Amps- 800 Amps 3∅ Buss Mt. 36”h X 48”w X 11”d hinged door 6019-HEL (LUG-LUG) 50PAGE 4951 Clark Public Utilities — Commercial Electric Service HandbookChapter 4: Commercial Metering / January 2011 33 1 in. electrical conduit FINAL GRADE 6 ft. maximum 5 ft. preferred 5 ft. minimum 30 in. wide conduit 35 ft. maximum 11 in. deep 36 in. tall 18 in. minimum hinged door required, hinges on opposite side of CT enclosure from meter socket permanent load and line identifying labels corresponding to appropriate connections ground per NEC ground per NEC Load Line Test Switch CT mounting base Installation requirements for current transformer mounting bases are as follows (Figure 9):  Mounting base is rated for a minimum of 50k amps fault current.  Line and load side terminations require two bolts per connector and two bolts on the neutral bus.  The customer furnishes all lugs and terminates both load and line side conductors to the bus.  A 4-wire delta service requires orange marking of the high leg. Switchboard metering Switchboard metering is required for three-phase services over 800 amps. At the customer’s option, this type of metering may be installed for services sized 201 to 800 amps. The customer-installed equipment must be EUSERC-approved. Figure 8Typical 401–800 amp single-phase current transformer (CT) metering 50PAGE 5051 Clark Public Utilities — Commercial Electric Service Handbook 34Chapter 4: Commercial Metering / January 2011 N CT 7 in. minimum7 in. minimumtwo CT mounting bolts, 6 places typical bus marking “CT” typical 3 locations 10–32 machine screw and washer drilled and tapped into bus insulating support insulating barrier 5 in. minimum 1-1/2 in.7/8 in. 3/4 in. 1-3/8 in. 1-3/8 in. 1/4 in. 8-1/8 in. 3-5/16 in. CT CT All customer-installed switchboards require a:  Current transformer ( CT ) mounting base.  Service section.  Set of bus bars/links.  Panel(s).  Meter base with provisions for a test switch.  Means for locking the meter enclosure with independent 24-hour access to utility personnel.  Concrete mounting pad.  Case ground as required per the NEC. NOTE: Customers requiring more than 480 volts of service will have primary metering. Ownership and maintenance agreements for primary metered servi ces will be mutually agreed upon with Clark Public Utilities. Figure 9Commercial three-phase CT mounting base NOTE: For additional information see EUSERC drawing 329B. 50PAGE 5151 Chapter 4: Commercial Metering / January 201135 Clark Public Utilities — Commercial Electric Service Handbook Multiple metered services Commercial tenant spaces Non-residential multiple meter installations such as ganged, modular and switch- board metering have the following requirements:  Spacing to socket centers a minimum of 3 feet and a maximum of 6 feet ab ove the nished grade or the oor of an approved equipment room (factory-built meter packs require meters installed at least 3 feet above the ground).  Meter packs with more than six meters require a main disconnect per the NEC (Figure 10).  All self-contained meter bases require a safety socket or a manual link bypass.  Each metered service is permanently labeled. (See Multiple meter labeling section for additional information.)  Panel covers must be secured prior to connection of the service. Figure 10Multiple meter socket detail Main disconnect service entrance disconnect required if more than six meters address label with minimum 1 in. letters floor or finished grade 3 ft. min. 6 ft. max. 8-1/2 in. min. 7-1/2 in. min. 6 ft. maximum 5 ft. preferred 5 ft. minimum hard plastic, metal or phenolic block labels with raised or engraved letters meter and corresponding disconnect labeled with unit number using minimum 1/2 in. letters building meter labeled “HOUSE” with minimum 1/2 in. letters Bldg B 123 Clark St 100 100 200 200 300 400 500 600 300 400 500 600 HOUSE NOTE: See page 31 for meter base bypass requirements. 50PAGE 525144-52
Three-Phase Transformer Set50PAGE 5551 50PAGE 5651 50PAGE 5751 50PAGE 5851 50PAGE 595155-59
Open Wye-Open Delta Padmount Installation50PAGE 6051 50PAGE 615160-61
Single-Phase J-Box50PAGE 6251 50PAGE 635162-63
Three-Phase J-Box50PAGE 6451 50PAGE 655164-65
Temporary Electrical Service50PAGE 665166


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