ENGINEERING DESIGN STANDARD

ELECTRICAL ENGINEERING DESIGN STANDARD FOR CABLE INSTALLATION NOTES AND DETAILS Page 1 of 37 TABLE OF CONTENTS Page LIST OF NOTES 3 LIST OF FIGURES 5 1.0 PURPOSE 7 2.0 CODES, STANDARDS AND REFERENCE DOCUMENTS 7 3.0 PROCEDURE 7 4.0 CABLE INSTALLATION GUIDELINES 8 4.1 Receiving, Handling, and Storage 8 4.2 Cable Pulling Tensions 8 4.3 Minimum Bending Radius 9 4.4 Cable Pulling Devices 9 4.5 Cable Termination 10 LIST OF NOTES 1. The routing for all scheduled cables is given in the circuit Schedule and deviations from these routings are not permitted without prior approval from Engineering. Routing of non-scheduled cable is by Construction. 2. Cables shall be installed without splices. Splices, when required, shall be made in manholes or pull boxes. Splices shall not be pulled into raceways. Splices shall not be made in any cable unless shown on the design drawings or by prior written approval from Engineering. 3. As a rule, cables shall not be installed in partially completed raceways. When field conditions dictate that cable must be partially in partially completed raceway, the responsible field electrical engineer shall determine that completion of the raceways will not result in any damage to the installed cables. 4. Cable shall be formed to avoid sharp bends over edges of conduit bushings upon entering or leaving boxes or cabinets, and to avoid bearing against the edges of cable tray or enclosure and supports when entering or leaving tray or enclosures. 5. Where maintained spacing of cables in a tray is required, tie cable to the tray bottom at approximately 6 feet intervals. 6. Cables shall be secured to the cable tray with cable ties at a maximum spacing of 5 feet on vertical cable tray runs. 7. Cables shall not be tied down in random filled horizontal trays, except at fittings (elbows, tee's etc.). 8. Cable installed in vertical conduit runs shall have one cable support (Hubbell Kellems Grip, OZ type or equal) provided at the top of the vertical conduit, or as close to the top as practical, and an additional support each interval of spacing as indicated on Table 1. LIST OF TABLES TABLE 1 Cable Support Spacing Requirement for Vertical Installation TABLE 2 Cable Bending Requirement TABLE 3 Dynamometer Multipliers TABLE 4 Clamping Bolt Tightening Torque LIST OF FIGURES FIGURE 1 Proper Stripping Length FIGURE 2 Thermocouple Terminations FIGURE 3 Cable Drain Wire Termination FIGURE 4 Terminal Bending Limit FIGURE 5 Low Voltage (1000V or Less) In-Line Splice (Non-Class 1E) FIGURE 6 Low Voltage (600V) Stub-Type and In-Line Motor Connection (Non-Class 1E) FIGURE 7 Medium Voltage (5-8 kV) In-Line Splice for Solid Dielectric Single Conductor Cable (Non-Class 1E) FIGURE 8 Medium Voltage (15 kV) In-Line Splice for Solid Dielectric Single Conductor Cable (Non-Class 1E) FIGURE 9 Medium Voltage (5-15 kV) Shielded Cable Termination for Non-Class 1E Applications and Class 1E Application Outside Containment FIGURE 10 Low Voltage (1000V or Less) In-Line Butt Splice and Bolted Connection for Nuclear (LOCA) Qualified Applications (Class 1E) FIGURE 11 Low Voltage (1000V or Less) Control Cable In-Line Splice for Nuclear (LOCA) Qualified Application (Class 1E) FIGURE 12 Low Voltage (1000V or Less) Control Cable Transition Splice to 1/c Wires (Penetration Leads) for Nuclear (LOCA) Qualified Applications (Class 1E) FIGURE 13 Low Voltage (1000V or Less) Instrumentation Cable In-Line Splice for Nuclear (LOCA) Qualified Applications (Class 1E) FIGURE 14 Low Voltage (1000V or Less) Instrumentation Cable Transition Splice to 1/c Wires (Penetration Leads) for Nuclear (LOCA) Qualified Applications (Class 1E) FIGURE 15 Low Voltage (1000V or Less) Multiconductor Cable Breakout for Nuclear (LOCA) Qualified Application (Class 1E) LIST OF FIGURES (continued) FIGURE 16 Low Voltage (1000V or Less) Stub-Type Motor Connection for Nuclear (LOCA) Qualified Applications (Class 1E) FIGURE 17 Low Voltage (1000V or Less) Stub-Type Control and Instrument Connection for Nuclear (LOCA) Qualified Application (Class 1E) FIGURE 18 Medium Voltage (5-8 kV) In-Line Motor Connection for Nuclear (LOCA) Qualified Applications (Class 1E) 1.0 PURPOSE The purpose of this document is to provide a standard guidance to construction for the installation of electrical cable. 2.0 CODES, STANDARDS AND REFERENCE DOCUMENTS a) National Electrical Code (NEC) b) Institute of Electrical and Electronic Engineers - Standard 383 c) American Petroleum Institute - RP 540 Recommended Practice for Electrical Installations in Petroleum Processing Plants d) Underwriters' Laboratories (UL) e) IEEE Standard No. 48 "IEEE Standard Test Procedures and Requirements for High Voltage Alternating Current Cable Terminations." f) IEEE Standard No. 422 "IEEE Guide for the Design and Installation of Cable Systems in Power Generating Stations." 3.0 PROCEDURE The standard notes and details shown herein shall be issued for each project. The notes in this document are used to define some degree of responsibility and construction practices. Additional notes maybe added as required to meet specific installation requirements during engineering and construction phases of the project. The details provide some typical examples of cable installations. Implementing these details will be the responsibility of the project engineering. Calculations to support cable installations and special conditions will be performed by the project engineering group or the responsible field engineer as required. Additional details maybe added to meet specific installation requirements during engineering and construction phases of the project. 4.0 CABLE INSTALLATION GUIDELINES 4.1 RECEIVING, HANDLING, AND STORAGE a) In fossil plants the field shall receive, unload and store cable and associated material in accordance with the manufacturer's instructions. b) In nuclear plants the level of storage and protection, as described in ANSI N45.2.2, required for the material covered by this standard is as follows: 1. Indoor Storage (Level C) (a) Cable terminals (b) Cable termination/splice material (c) Insulation for busbar connections (d) Cable ties (e) Cable marking inks (f) Instrumentation cable 2. Outdoor Storage (Level D) (a) Power and control cable c) The field shall perform and document receiving inspections. Verify that the voltage, type of installation, size and reel marking are correct for the type of cable received. d) During storage, the ends of the cables shall be effectively sealed to protect against the absorption of moisture. e) The Field shall review the cable manufacturers' temperature limits prior to handling or pulling cables during extreme cold temperatures. 4.2 CABLE PULLING TENSIONS a) Field Engineering shall compare the actual routing of conduit or duct with that shown on the design drawings for all critical runs. If any deviation in the design configuration of the routing is found which field engineering feels is pertinent to the pulling tension, the cable's expected pulling tension and maximum allowable pulling tension shall be recalculated by Field Engineering. b) Field Engineering shall ensure that the expected pulling tension and maximum allowable pulling tension on all cables scheduled for installation in exposed conduits is within acceptable limits. c) All cables shall be installed in raceway systems having suitable pull points (pull boxes, manholes, etc.) to avoid overtensioning the cable during installation. 4.3 MINIMUM BENDING RADIUS a) To avoid damage to the cable sheathing, jacketing and/or insulation, the cable bending radius shall be as large as installation conditions permit. b) If not specified by Project Engineering, the following shall be the minimum bending radii for installation and training of cable. R = D x M Where: R = Minimum Bending Radius D = Overall Diameter of Cable M = Multiplier (refer to Table 2) 4.4 CABLE PULLING DEVICES a) Cable may be pulled with a pulling grip attached directly to the conductors or by a basket grip over the sheathing, jacketing and/or insulation. b) The maximum tension on each basket grip shall not exceed 2000 lbs when pulling non shielded cable. The maximum tension on each basket grip shall not exceed 100 lbs when pulling shielded cable. c) Bare wire rope or plastic coated wire rope shall not be used for pulling cable. d) Lubricating compounds shall be used in pulling cable into conduit, when required, to prevent excessive pulling tensions. Only pulling compounds compatible with the cable jacket (Polywater J or equal) shall be used. Do not use pulling compounds that set up in the conduit. Caution should be exercised when pulling cables through totally enclosed raceways (conduit) entering electrical equipment enclosures, where the possibility of cable lubricants migrating onto exposed electrical equipment exists. Conduits shall be sealed in such cases to prevent migration of cable lubricant. e) Installation tensions of critical cable pulls (as defined by Project Engineering and the Field) shall be monitored using a dynamometer or tensionometer. The Field shall document all dynamometer / tensionometer readings. f) A tensionometer placed in the pulling line will indicate directly the actual cable tension while a dynamometer will require a reading correction for the incidence angle of the pulling lines. Table 3 lists the dynamometer multipliers for angles from 0 to 90. g) If the maximum allowable pulling tension of a cable is exceeded during installation, the Field shall, immediately upon completion of the installation of the cable, test the cable in accordance with Section 6.8 herein. The results of all tests shall be submitted to Project Engineering. h) Second or third pulls (or more) of cable through occupied conduit -or duct (pull-by) shall be avoided. When necessary, the pull-by shall be authorized and supervised by the field electrical engineer. 4.5 CABLE TERMINATION a) General Termination Information 1. Cables pulled into cabinets and panels shall have sufficient cable length left for connections. Separation requirements within nuclear project panels shall follow IEEE 384 and NRC R.G. 1.75 prior to terminating conductors. 2. Compression type terminals shall be attached to the cable conductor with a crimping tool approved by the connector manufacturer for the type and size of conductor. 3. The crimping tool for cable sizes larger than #4/0 AWG shall be hydraulically operated. 4. The Field shall install the permanent cable marker at each end of the cable after the cable is terminated. 5. All motor terminations inside nuclear reactor containments subjected to LOCA environmental conditions shall be terminated with Raychem Type-N termination kits, or Project Engineering approval equal. See figures. b) Control and Instrumentation Cable Terminals for low level signals for control and instrumentation cables (No. 22 to 10 AWG) and for 600 V power cable #8 AWG and smaller shall be ring tongue or locking fork insulated type using material other than PVC for the insulation. The terminal shall be applied with a crimping tool approved by the manufacturer of the lugs. 1. The cable jacket of multi-conductor cables inside equipment shall be maintained intact as close as reasonably possible to the conductor termination. 2. Only two field terminations shall be permitted at any outgoing terminal block point. 3. When two terminals are located on the same terminal block point, the bottom terminal should be installed upside down. 4. Shielded Cable (a) Shield tapes or drain wires should be insulated from all other shield taps or drain wires with insulation tubing or heat shrinkable tubing to prevent short circuits and circulating currents. Solid drain wires should be terminated to the termination point without using a compression terminal. The wire should be formed into a hook and secured by the terminal screw. Stranded drain wires and shields should be terminated using a properly sized terminal. (b) If the drain wire is carried through the terminating point ungrounded then it must be insulated from ground and other drain wires. An example of this would be the electrical containment penetrations in a nuclear plant. (c) If the drain wire is being grounded at a terminating point then the drain wire does not have to be insulated at the location. (d) If the drain wire at a terminating point is the floating end then it must be insulated from ground. An example of this is the RTD cable that is grounded at the equipment end. (e) If a cable has multiple drain wires that are to be floated then they can be cut back but each must be insulated from each other as well as from ground. c) Thermocouple Extension Cable 1. When terminating two solid thermocouple wires of the same conductor metal, the insulation of the wires should be stripped back approximately 1 inch and the conductors twisted tightly together. The twisted wires should then be formed into hook to fit the screw shaft of the block point closely and fastened into place by tightening the screw. 2. Stranded thermocouple wire should be terminated or spliced using a terminal recommended by the cable manufacturer. d) Coaxial, Triaxial, and Other Specialty Cable 1. Care should be exercised to ensure that only lug types specifically approved by the able manufacturer are used. An important responsibility of the Installer is to ensure compatibility between cable, cable termination device, and the mating connector elements provided in the equipment. e) Power Cable Terminations - 600 Volts and Below 1. Power cable terminations for #6 AWG and larger conductor sizes shall utilize crimp type lugs sealed at the tongue end to prevent entry of moisture. The lug shall be applied with a crimping tool approved by the manufacturer of the lug. Manually operated crimping tools shall be designed so that after a compression stroke has been started, opening of the tool handle is prevented until full crimping action is completed. The cable lugs and tools shall be coded to ensure the proper crimping die has been used. 2. Conductors of dissimilar metals shall not be placed in physical contact with each other. Where dissimilar conductors are to be electrically connected, use only special connectors intended for this specific purpose and condition of use. When aluminum conductors are to be connected onto copper terminals or copper conductors on aluminum terminals, a special (Cu-Al) lug, compatible with both metals, shall be used. 3. Bi-metallic stranded pin connectors (T&B 61905 series, Homac type BMS or equal) shall be used when mechanical lugs are used to terminate aluminum cable. Pin terminators and butt-splice reducers should only be used where necessary. Their use shall have prior approval of Project Engineering. 4. An oxide inhibiting compound shall be used when ever unplated aluminum must make electrical contact with another metallic surface. All copper and aluminum lugs shall be tin plated. 5. For conductor sizes #2/0 AWG and larger, a minimum of two bolt holes per lug contact pad shall be used. Number, size, and arrangement of multiple bolt holes shall comply with NEMA standards. 6. Plated steel bolts or high strength silicon bronze bolts shall be used for all bolted lug connections. Flat washers and lock washers shall be used to bolt aluminum to aluminum or aluminum to copper connections. Bolted connections shall be torqued in accordance with Table 4. 7. Where connections are made which are not structurally supported by the equipment to maintain adequate flashover distance (such as in many motor terminal boxes), the entire connection must be properly insulated. The preferred method of doing this is by use of appropriate heat-shrinkable polyolefin tubing (Raychem type MCK, 3M PST-Prestretched Tubing or equal). Proper taping by hand is an acceptable alternative (3M-Scotchfil Putty and Scotch 33 + tape). f) Power Cable Terminations - Medium Voltage 1. Specific approval of the cable manufacturer should be obtained for the devices, methods, and materials to be used in making terminations. 2. Equipment rated at voltages above 600 volts shall have buses and other energized parts in the terminal compartment protected by an insulation covering. In every case, each entire connection shall be completely enclosed with insulation suitable to the voltage class involved. 3. For requirements of lug installation and connection see Section 4.5.e. 4. The rubber tape shall be an EPR base type specifically intended for high voltage cable. An alternative method (which is qualified by the manufacturer to IEEE Standard 383 for nuclear Class 1E applications) is Raychem heat-shrinkable polyolefin tubing type HVBC and NHVBC. A third method is to utilize split premolded high voltage boots of an approved type which snap in place to cover exposed energized parts. The latter two methods can be applied directly over the lug and terminal. Where hand taping is used, an approved cable insulating putty should first be applied to smooth over the irregular surfaces of bolts, nuts, etc., protecting the tape from cut-through. (Note: most duct sealing material is NOT approved for this application.) 5. When a shielded cable is to be terminated, the insulation shield (which normally should be at ground potential) must be removed from the end of the cable for a length sufficient to prevent flashover from the exposed conductor to the shield. The line, encircling the cable, beyond which the insulation shield has been removed, marks a vicinity of high concentration of dielectric stress on the cable insulation. To prevent almost certain failure of the cable at this point, stress must be relieved. Three different methods are approved for indoor installations; hand-taping, preformed or premolded "stress cone" devices, stress-grading heat-shrinkable tubing, or porcelain potheads. 6. Preformed terminations and heat-shrinkable types are suitable for nominal phase-to-phase voltage classes through 35 kV. Above this level, potheads must be used. g) Prefabricated Cable Assemblies 1. Prefabricated cable assemblies supplied by the associated equipment vendor or the cable assembly vendor will be identified. 2. The vendor will provide pre-cut cable lengths for individual cables. These lengths will be supplied by engineering. A connector will be installed on one end of each cable length and will be tagged. Where the vendor is supplying connectors for both ends of the cable assembly, the connector not installed by the vendor will be bagged, identified and supplied with the corresponding cable assembly. Care must be taken when pulling these cable assemblies to ensure that the vendor installed connector end of the cable assembly is at the correct location. 3. The prefabricated cable assemblies shall not be pulled with any gripping device attached at the connector end of the cable assembly unless approved by engineering. 4. Protective caps for connectors (where provided) shall be kept in place during cable pulling operations and until the cable is actually terminated. h) Tests 1. After terminations are installed but before cables are connected to equipment at either end, the integrity of all medium voltage cable and terminations shall be verified by means of Hi-pot dc testing. These tests should be in accordance with IEEE Standard No. 48. i) Documentation (Nuclear) 1. All Class 1E cable terminating material shall be qualified for operation in accordance with IEEE 383. 2. With consideration to the Service Conditions defined above, certified test results shall be provided of all prototype tests required by IEEE 383. The Supplier shall certify that the test results submitted are from tests made on samples identical in construction, materials, and processing methods as those furnished for use. Certified test results, as required by IEEE 383, are not required for cable ties which require a Certificate of Conformance to show their suitability for the intended service environment only. 3. The Supplier shall provide certified tests reports for all production tests. j) Tools and dies 1. The tools and dies provided to crimp the connectors shall be constructed to assure uniform, quality-assurable compression terminations. The tools shall be constructed in such a way to prevent under-crimping and over-crimping. The dies of all application tooling shall provide integrity coding for quality control verification. The tools shall be easily identified by permanent markings. The identification shall, as a minimum, show: (a) Manufacturer's name and equipment number. (b) Size of wire or range of wires that the tool is designed for. (c) Serial number unique to that individual tool. 2. A program shall be provided by the Field to periodically verify the tools and dies for proper crimping of conductor terminals. 3. All tools utilized for crimping of terminations shall be recommended or approved for use by the connector Supplier. 4. Where terminations are provided by the equipment Supplier, the tools used for crimping shall be compatible with the provided termination. TABLE 1 CABLE SUPPORT SPACING REQUIREMENT FOR VERTICAL INSTALLATION Cable Size Max. Support Spacing # 18 AWG to # 1/0 AWG 100 feet # 2/0 AWG to # 4/0 AWG 80 feet 220 kcmil to 350 kcmil 60 feet 350 kcmil to 500 kcmil 50 feet 500 kcmil to 750 kcmil 40 feet Above 750 kcmil 35 feet TABLE 2 CABLE BENDING REQUIREMENT Minimum Bend Minimum Bend Radii for Radii for Installation Training of of Cable Cable Type of Cable Multiplier (M) Multiplier (M) Medium Voltage Power Cable 5 to 15 kV shielded tape or braid 12 12 5 to 15 kv shielded drain wire type 8 8 Lower Voltage Power 1/C or multi-conductor 2 kV and below, larger than 500 kcmil 6 5 2 kv and below, 500 kcmil and smaller 5 4 Control Cable 600 V and below 4 3 Instrumentation Cable Multi-conductor 4 3 Coaxial/Triaxial * - Per cable manufacturers recommendations. TABLE 3 DYNAMOMETER MULTIPLIERS ANGLE MULTIPLIER ANGLE MULTIPLIER (DEGREES) (DEGREES) 0 0.50 50 0.552 5 0.50 55 0.564 10 0.501 60 0.577 15 0.504 65 0.593 20 0.508 70 0.610 25 0.512 75 0.630 30 0.518 80 0.653 35 0.524 85 0.678 40 0.532 90 0.707 45 0.541 TABLE 4 CLAMPING BOLT TIGHTENING TORQUE Bolt Size (inches) Inch-Pounds Foot-Pound 5/16 180 15 3/8 240 20 13/32 288 24 7/16 360 30 1/2 480 40 9/16 576 48 5/8 660 55 3/4 840 70