Marine Institute of Memorial University of Newfoundland Electrical Installation Booklet Shipyard Standards Marine Engineering Systems Design Department Revision 0
List of Revisions Revision Description Date 0 INITIAL ISSUE SEPT/08/2010 Page 2 of 81
Abstract The standards described in this document are primarily intended for Marine Engineering Systems Design students enrolled in the three year Diploma of Technology program. Introducing design standards to the classroom at the Marine Institute serves two purposes. First, it makes students aware such standards exist and familiarizes them with the format and use of such standards as found in the shipbuilding industry. Secondly, design standards will allow a class of students to work to the same standard and therefore produce similar quality drawings as would be expected by industry drawing offices. This standard can be used as a constant source of reference by all students. It should be noted that most engineering and design offices employ their own standards to which all engineers and designers must adhere. The primary purpose of the standard is to allow the designer to reference a particular standard detail on a working drawing and thereby not have to draw this detail. In the classroom at the Marine Institute, this is not the case; standards used by the student are expected to be drawn and fully detailed. Instructors may deviate from this standard depending on the type of lab/drawing work being done. Page 3 of 81
Index List of Revisions...2 Abstract...3 Index...4 General Notes:...5 Section 1: Cable Hangers / Supports and Accessories...13 Section 2: Cable Penetrations...30 Section 3: Mounting for Boxes, Panels, etc...48 Section 4: Lighting Fixture Mounting Supports & Brackets...53 Section 5: Stuffing Tubes & Multi-Cable Transits Packing...59 Section 6: Cable Entrance into Equipment...68 Section 7: Grounding of Electrical Equipment...71 Section 8: Cable Penetration and Repair...80 Page 4 of 81
General Notes: 1. Cable type letters and size designations: Cables are identified by type and size designations which consists of letters indicating the construction, followed by numerals indicating size. The type letters used in describing the construction of the cable are as shown in the following legend: Cable Type Insulation Jacket Armor S Single Conductor Distribution E Ethylene Propylene Rubber I Moisture Resistant Jacket, Type T, CP, or N A Aluminum D Double Conductor Distribution X Cross-Linked Polyethylene B Bronze T Three Conductor Distribution GVT Impregnated Glass Varnished Cloth C Control M Mineral TP Signal (twisted pair) S Silicone TPS Shielded Signal (twisted pair, shielded) T Polyvinyl Chloride T/N LSE LSX PVC/Polyamide, 75 degree C cable LSEPR, Low Smoke Ethylene Proplene Rubber LSXLPE, Low Smoke Cross Linked Polyethylene, 90-deg C cable P XPLO Cross Linked Polyolefin Example: Type TXIA = Three conductor, cross-linked, polyethylene insulated, jacketed, aluminum armor. (IEEE 45) The size designation relates to the conductors and may indicate one or more of the following: ( A ) Size of Conductor Example: The conductor are of type TXIA-66 is approximately 66,000 CM (exactly 66,400 CM). ( B ) Number of Conductor Example: C14TIA-14 contains fourteen insulated conductors 4,410 CM each. Page 5 of 81
( C ) Number of Twisted Pairs Example: TIPIA-16 contains 16 twisted pairs, or 32 conductors, each 1,119 CM. ( D ) All armored cable installed in the weather shall be impervious sheath, with bronze armor. Legend for low smoke cable is in MIL-HDBK-299 (SH), Paragraph 5.1. 2. Cable identification: All permanently installed cable shall be identified with its circuit designation embossed on soft aluminum tape 1/2" wide min. as close as practicable to each point of connection for cables not exposed to the weather. Nylon cable tags shall be used for tagging cable on weather decks. Brady PVC polyvinyl chloride sleeve markers or equivalent may also be used to identify circuit designation if installed on a ty-wrap around the cable and the cable is not exposed to the weather. Cables shall be tagged in readily accessible positions where they can be read without danger. to personnel, at cable, ends only if both ends of a cable can be seen only one tag is needed at either end. Special precautions need not be taken to prevent paint from covering the cable tags. Medium voltage (4160) cables shall be identified with a red tag at cable ends. 3. Conductor Identification: All conductors shall be provided with wire markers or tags at each end by one of the following methods: ( A ). Synthetic resin tubing or approved plastic wire markers. ( B ). Heat shrink tubing. ( C ), Brady vinyl cloth wire markers, self-sticking. Where separate markers are used, they shall be attached as near as possible to the terminals marked so as to preclude faulty identification. Page 6 of 81
4. Conductor Phase Identification: To facilitate identification of conductors and correct connection of phases, the individual conductors of two, three, and four conductor distribution cables shall be color coded as follows: Two conductor cable black, red or white Three conductor cable black, blue, red Four conductor cable black, red, blue, orange or white In three phase circuits the colors shall identify the phases as follows: Black - phase A White or blue - phase B Red - phase C The connection of single phase. two conductor cables to three phase circuits shall be as follows: Phase AB, black " A ", white or red " B " Phase BC, white or red " B ", black " C " Phase CA, white or red " C ", black " A " Phase rotation or sequence for all three-phase systems shall be in the following order: AB, BC, CA. The order of the phases in wiring boxes, distribution panels, switchboards, etc. shall be A, B, C from left to right, top to bottom, front to back as viewed from the front of the equipment. 5. Cable Lug Terminals: All cable connections shall be made by solder less type lugs of an approved clamp or compression type, adjustable within reasonable limits for various conductor diameters terminal lugs for interior communication or radio cables or for # 16 AWG or smaller internal control wiring on panels, etc. may be of the soldered or crimped type, or may have the wire formed into an eye, and solder-dipped. Terminal lugs shall be of the two-hole type, or for terminals where it is impracticable to use two fastening bolts, a locking feature shall be used to prevent the one-hole lug from turning in any direction after fastening. All lugs and terminals shall be made from high-conductivity copper, UL approved, tin plated. All bolts, screws, nuts and washers-shall be made of non-corrosive material or of material rendered adequately corrosion resistant and be of adequate size for their function. Page 7 of 81
6. Wire nuts: Approved twist-on pressure type connectors (wire nuts) may be used for connecting conductors up through no. 10 AWG in 120 and 450 volt power circuits, in lighting circuits, small appliances and in fractional horsepower motors. Wire nuts shall not be used in I.C. telephone or electronics systems. 7. Cable location: Except where unavoidable, cables shall not be installed in the following locations and hazardous conditions: 1. spaces where excessive heat may be encountered. 2. spaces where inflammable or explosive gases may be present. 3. exposed side of deckhouse. 4, spaces which may subject cable to oil damage. 5. behind or embedded in structural heat insulation. 6. inaccessible spaces. 7. spaces where excessive moisture is encountered. 8. areas where cable would be subjected to mechanical damage. 9. bilges. Cables shall be run so as to prevent harborage of rats. The running of cables on weather decks shall be avoided as far as practical. Wherever practical, cables to weather deck mounted fixtures shall be run on the inside surface of the structure supporting such fixtures. Cables for weather deck fixtures shall be installed on the inside surface of house structures supporting such fixtures. At each end of each of these cables, a length of excess cable in the form of a free loop equal to the length of cable exposed to the weather shall be included. 8. Cable protection: All electrical cable to open deck-mounted equipment shall be adequately guarded with pipe or other substantial protection. During the course of the work, all new and existing cable ends are to be protected from the entrance of moisture. All electrical systems, cable and equipment shall be megger tested prior to energizing. 9. Cable bends: All cables shall lie outside a radius which is 8 times the diameter of the largest cable in a run. Coaxial cable which is not repeatedly flexed shall lie outside a radius which is 12 times the diameter of the largest cable in the run (10 times is minimum). Coaxial cable which is repeatedly flexed shall lie outside a radius which is at least 20 times the diameter of the largest cable in the run. Page 8 of 81
10. Cable supports on decks and bulkheads: Cables in detailed wire ways shall be strapped in position at every hanger on vertical runs and on horizontal runs at every fourth hanger in straight sections and every hanger at turns and at break-outs. 11. Cable penetrations through decks and bulkheads: Where cables pass through watertight bulkheads, a watertight stuffing tube assembly shall be employed except that multi-cable transits may be used for groups of cables. Where cables pass through watertight decks, a watertight stuffing tube assembly shall be used, except that watertight riser boxes or multi-cable transits may be used. For groups of cable, where cables pass through non-watertight bulkheads, beams, or similar structural parts, where the bearing surface is less than 1/4 inch, the holes shall be fitted with bushings having rounded edges and a bearing surface for the cable of at least 1/4 inch in length. Where cables pass through non-watertight bulkheads, beams, or similar structural parts, where the bearing surface is 1/4 inch or greater in length, all burrs shall be removed in way of the hole, and sharp edges shall be eliminated. 12. Stuffing and terminal tube application: Steel stuffing tube assemblies or multi-cable transit devices shall be used for cable penetrations of watertight decks and bulkheads. Nylon terminal tubes can be used for cable entrance into brass, sheet steel and aluminum enclosures when located in the interior of the ship. Where space limits the use of nylon terminal tubes, metal terminal tubes may be substituted. Where brass enclosures are located in the weather, brass terminal tubes shall be used. 13. Location of connection boxes: To the extent possible, all terminal and connection boxes shall be i n a position of maximum accessibility. Provide access, identified by nameplates, to all connection and terminal boxes in finished areas. In general, such locations shall be in wardrobes where possible. Page 9 of 81
14. Identification of emergency lighting fixtures: All emergency lights shall be marked with the letter "e" that is at least one inch high and red in color. 15. Drip pans and shields: Where electrical equipment i s exposed to injury or damage caused by leakage of oil, water, steam, etc., or excessive heat, suitable drip pans or shields shall be installed. 16. Painting electrical equipment: Electrical equipment shall be protected from painting where necessary. 17. Painting ship structure in way of equipment: The surfaces of ship structure, foundations, and mounting brackets in way of electrical equipment shall be painted before installation of the equipment. 18. Grounding of electrical equipment and cable: All paint, dirt and rust shall be removed from faying surfaces of equipment feet and foundation before mounting equipment. The frames or casings of all permanently installed generators, motors, controllers, instruments and similar equipment, for which the arrangement and method of installation does not insure positive grounding, shall be permanently grounded through separate straps or cable, securely attached and protected against damage. All portable equipment energized by a portable cord and plug shall have all exposed metal parts grounded by the third (green) conductor in the portable cable and grounding device in the receptacle and plug. For cable provided with a metallic sheath or armor, the sheath shall be continuous from outlet to outlet and shall be grounded at each end except that for final subcircuits the sheath may be grounded at the supply end only. Page 10 of 81
19. Cable slack requirements: Cables shall be installed so that sufficient slack exists to allow for deflection of bulkheads. Where cables spread out to enter bulkhead-stuffing tubes, bends shall have liberal sweep to provide as much flexibility as practicable. Cables having only a minimum spread where they pass through bulkhead stuffing tubes shall have enough slack to give them the same flexibility as other cables in the group. Cables from switchboards, or other electrical equipment, shall enter wire ways in a curve of sufficient radius to prevent transmitting stresses to the equipment during severe wire way deflections. 20. Cables entering motors and control equipment:: Where possible, cables entering motors and control equipment should enter-from the bottom. 21. Cable bunching and double banking: Cable bunching shall be restricted to a maximum of 6 cables. Double banking of power cables will not be allowed without prior approval from engineering. Cables serving systems above IKV are not to be bunched with cables serving systems of IKV and below. Except for fiber optic cables, non-shielded signal cables for automation and control systems, essential for the safe 0peration of the vessel which may be affected by electromagnetic interference are not to be run in the same bunch with power or lighting cables. 22. Electrical installation methods: Methods shown on body of wire way plans are typical and not necessarily actual. Page 11 of 81
23. Conductor repair of cable: Should the insulation of an individual conductor be damaged, it shall be immediately brought to the attention of the attending ABS surveyor. Inspection by the surveyor is needed to establish the location and extent of the damage and determination of whether a splice, junction box, or replacement of the cable in its entirety is needed. If the cable is repaired, the insulation repair is equivalent to the splice and is to be to the satisfaction of the surveyor. Damaged propulsion cables, cables for repeated flexing service, and cables in hazardous locations are not to be repaired. Junction box and splice locations are to be shown on the vessel s Electrical Equipment Arrangement drawing. 24. Ty-wrapping of cables: Ty-wraps may be used to band cables 1/2" dia. Or less. In vertical runs, all cable sizes may be ty-wrapped. In horizontal runs only where cable will not fall if the retention fails. Page 12 of 81
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Section 2: Cable Penetrations Page 30 of 81
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Section 3: Mounting for Boxes, Panels, etc Page 48 of 81
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Section 4: Lighting Fixture Mounting Supports & Brackets Page 53 of 81
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Section 5: Stuffing Tubes & Multi-Cable Transits Packing Page 59 of 81
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Section 6: Cable Entrance into Equipment Page 68 of 81
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Section 7: Grounding of Electrical Equipment Page 71 of 81
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Section 8: Cable Penetration and Repair Page 80 of 81
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