1.0 SCOPE TABLE OF CONTENTS 2.0 CABLES SPLICES 2.1 Definitions 2.2 Scope of Specifications and Drawings 2.3 General Requirements 2.4 Routing Cables 2.5 Connectors 2.6 Conductor Connections 2.7 Heat Shrinkable Splices - 600 Volts Through 35 kv 2.8 Phasing of Cable Splices 2.9 Cable End Caps 3.0 CABLE TERMINATIONS 3.1 General 3.2 Precautions in Making Cable Terminations 3.3 Locating Cable Terminations 3.4 Grounding of Cable Terminations 3.5 Partial Discharge Measurement 3.6 Elbow Terminations PAGE NO. 2 OF 9
1.0 SCOPE This standard has been prepared as a guide for the splicing & termination of insulated cables with copper or aluminum conductor that will be used for 0.6/1, 11, 13.8, 33, 34.5, 69, 110, 115, 132, 230 and 380 kv underground cables circuits in the system of Saudi Electricity Company (SEC) Saudi Arabia. 1.1 General Requirements 1.1.1 All splices & terminations shall meet the requirements of applicable Saudi Electricity Company Material Standard Specification (12- TMSS-10), IEEE-48, IEEE-404 and in strict compliance with manufacturer s instructions. 1.1.2 The cables shall also meet the standards of SASO, AEIC, ICEA, IEC and/or any other internationally recognized organizations. 1.1.3 The high voltage cable terminations shall be installed in a professional manner with acceptable workmanship. Before commencement of work all cable splicing and terminating personnel shall obtain certification (from manufacturer or SEC) valid for a period of not more than one year from the date of issue stating that the person has been trained and is capable of accomplishing the task. 1.1.4 All GIS terminations shall be done under manufacturer s supervision and instruction, based on GIS termination drawings and installation instructions which shall be submitted to SEC for review and acceptance prior to starting the termination work. Personnel carrying out the terminations shall posses certificate from mother company and/or by an independent agency valid for a period of not more than one year from the date of issue. 1.1.5 The cables splicing and terminating operation shall be performed in a manner to mitigate the adverse effects of the environmental conditions specified in 01-TMSS-01. 2.0 CABLE SPLICES 2.1 Definitions The term "Cable Splice" as used in these specifications refers to all splices, solid taps and branches in insulated power cable as may be made in man holes, hand holes, splice boxes, vaults, tunnels, etc. This term does not apply to splices for pulling into ducts. The various types of cable splices referred to in this section are defined as follows: PAGE NO. 3 OF 9
2.2 Scope Straight Splice:- A splice between two cables having the same number of conductors. "Y" Splice:- A splice for connecting one cable to two cables, all of which have the same number of conductors. This section covers various types of cable splices for all types and sizes of insulated cable commonly used by SEC for high and low voltage power transmission. Cable splices, not covered here shall be made according to the cable manufacturer's recommendations and design. 2.3 General In making cable splices, the the splicer and/or terminator must be certified by manufacturer or SEC or an independent agency and shall specifically follow this section and the manufacturer's recommendations for the particular splice and type of cable being installed. Splicing power cables requires great care in the assimilation of manufacturer's instructions, utilizing prescribed materials with proper tools and above all, observing extreme cleanliness in all phases of the splicing operation. The cutting of the cable for splices also requires the observance of exact dimensions - length and depth in the preparation of the cable for the splicing procedure. The operation should be carried out in a proper dust free tent where humidity and temperature are controlled as per manufacturer's recommendations. The removal of the semi-conducting layers over the conductor and the insulation should be executed in a manner prescribed in the manufacturer's instructions for each splice. Similar recognition should be applied in the removal of the conductor, insulation and jacket. Unless otherwise permitted by SEC, all splicing operations shall be conducted in a double walled tent equipped with a positive pressure type air conditioning unit. The air conditioning unit shall be capable of maintaining the relative humidity below 40%. 2.4 Routing Cables Route the cables into their final positions, avoiding sharp bends and allowing the ends to overlap. The overlap for splicing power cable should equal the length of the completed splice. Also, it is desirable to have at least 150 m of straight cable beyond ends of finished splice. PAGE NO. 4 OF 9
2.5 Connectors Connectors for use in splicing shall be either compression or thermite welded types in accordance with the manufacturer's specific recommendations. 2.5.1 Compression connectors shall be suitable for aluminum or copper conductors. All connectors 35 mm 2 and above shall have tapered ends and metal barriers. Tapered ends will ease tape splicing and alleviate stress points on high voltage splices. 2.5.2 Solder type connectors shall not be used with solid dielectric cables. 2.5.3 When splicing copper to copper conductors, only copper connector shall be used. 2.5.4 When splicing aluminum to aluminum, only copper-aluminum or aluminum rated connectors shall be used. 2.5.5 When splicing copper to aluminum conductors, only copper aluminum rated connectors shall be used. 2.6 Conductor Connections 2.6.1 Preparation of Conductors The normal procedure for cleaning exposed bare conductor ends prior to installing connectors is brushing the surface of the conductor with a steel brush until it is clean and bright. When cleaning aluminum conductor for compression connections, it is necessary to apply an SEC approved inhibitor compound to the exposed conductors immediately after the wire brushings. The inhibitor compound will prevent the formation of a non-conductive film of oxide on the conductor surface, which would otherwise form as a result of the chemical reaction between the aluminum surface and air. 2.6.2 Application of Compression Connectors Care shall be taken always to select the recommended compression die for pressing the joint connector. It shall be installed in strict compliance with manufacturer's instructions for applying compression connectors. 2.6.3 Preparation of Cable Joint Surfaces After the cable joint connector is installed and prior to applying the insulation tape, or heat shrink material, the surfaces of the insulation and insulation shield must be thoroughly cleaned with a SEC approved cleaning fluid. The use of benzine, or gasoline, for this purpose, is not permitted. PAGE NO. 5 OF 9
2.7 Heat Shrinkable Sleeve Heat shrinkable polyethylene provides a recommended method for insulating underground splices for XLPE cables (600 V to 35 kv). If the manufacturer's splice kit does not include a heat shrinkable sleeve to protect the concentric neutral wires against corrosion, then one shall be installed. 2.8 Phasing of Cable Splices When the cable splices are installed for the purpose of circuit expansion or repair, the cables to be spliced shall be identified and labeled to correspond with phase indentification at the source side of the cable termination. Splicing of the cables in accordance with proper phase identification will eliminate the possibility of the splice introducing an out-of-phase condition in the circuit. 2.9 Cable End Caps During the period that cables have been placed in ducts or trenches, and are to be spliced at a later time, the cable ends are to be sealed to eliminate moisture entering and corroding the cable conductor. Heat shrinkable caps, shall be utilized and installed on open ends of the cables in order to maintain the integrity of the cable. 2.10 Partial Discharge Test Partial discharge measurements shall be carried out for high voltage cable 230 kv & 380 kv at site after completion of splicing/jointing of the cable to detect the weak points. The tests shall be carried out preferably during the HV test or immediately thereafter. 3.0 CABLE TERMINATIONS 3.1 General 3.1.1 Definitions The term "Cable Termination" as used in this Section refers to all terminations of insulated power cable in order to effect an electrical connection to the cable conductor. In its simplest form, a cable termination may be formed by attaching a suitable terminal lug to the end of a cable conductor. For insulated power cable, however, it is necessary to remove a section of the outer jacket and shielding (if applicable), to seal the cable end against the entrance of moisture, as well as provide a suitable electrical termination of the cable insulation shield by means of a stress cone. The method of sealing the cable end varies with the style of cable termination. PAGE NO. 6 OF 9
3.1.2 Taped Termination A taped cable termination is one in which the cable end is sealed by the application of suitable insulating tape. Taped terminations of power cables over 5 kv shall require the construction of a stress cone by building up the proper shape through consecutive layers of tape. 3.1.3 Premolded and Molded Terminations A premolded termination may be one of several types of slip on terminations constructed of rubber like synthetic materials or a combination of plastics and polymers. Terminations in this category include skirted one-piece terminations with varying creep distances, or elbow type of separable connections. The application of premolded and molded terminations shall be performed in strict compliance with the manufacturer's installation procedures. 3.1.4 Heat Shrink Terminations Heat shrink irradiated polyethylene is used to control terminal stress and provide a means of terminating 15 kv, 35 kv, 69 kv, 110kV, 115 kv, 132 kv, 230 kv and 380 kv cables, indoor and outdoor. The application of heat shrink irradiated polyethylene shall be performed in strict compliance with the manufacturer's installation procedures. 3.1.5 Porcelain Terminations Indoor and outdoor porcelain terminations are used for 69-380 kv rated cables, and shall be installed in strict compliance with the manufacturer's procedures. 3.1.6 SF6 Gas-Immersed Terminations SF6 Gas-Immersed terminations are used up to 380 kv rated cables, and shall be installed in strict compliance with the manufacturer's procedures. 3.1.7 Terminal Lugs Terminal lugs used for all cable terminations must be selected to insure the compatibility of the metal to metal contact. Where cables with aluminum conductors are to be terminated on copper bus, such as transformers or switchgear or on overhead copper line hardware, the terminal lug shall be rated copperaluminum. An oxide inhibitor PAGE NO. 7 OF 9
shall be applied to the aluminum conductor prior to compressing the terminal lug. 3.1.8 Leakage Distance For outdoor terminations, the leakage distance shall be a minimum of 40 mm/kv line-to-line and 50 mm/kv near the coastel area (preferably with High Voltage Insulator Coating (SYLGARD) for coastal/polluted areas). 3.2 Precautions in Making Cable Terminations In making cable terminations, the splicer and/or terminator must be certified by an independent agency and shall specifically follow the specifications, details, dimensions given on the manufacturer's drawings for the particular termination and type of cable being installed. Extreme care shall be taken in every step from start to finish to keep the cable termination free from moisture, dirt, particles of metal and air pockets. To accomplish this, the technician's hands, tools, containers and supplies must be kept clean, dry and free from foreign matter at all times. Do not expose unpacked premolded insulating materials to the atmosphere for more time than absolutely necessary (as suggested by the manufacturer). After the cable insulation has been exposed by removal of any section of the outer covering, operations should be continued without interruption until the cable termination is complete. Should it be necessary to leave an incomplete cable termination overnight, the exposed cable insulation shall be protected by a carefully applied covering of tape of the final type to be applied to the termination and, in damp locations, this tape shall be covered by a waterproof rubber or plastic tape. Suitable protection (depending on moisture and dirt conditions and the voltage of the termination being made up) shall also be applied to exposed insulation when terminating is interrupted for eating time or for necessary tests. The permanent storage of cable termination shall be strictly as per manufacturer recommendations 3.3 Locating Cable Terminations 3.3.1 Locating Terminations Cable terminations are frequently attached directly to the equipment terminals, buses or other conductors. This application determines to an appreciable extent, the location of the termination. However, there may be some choice with regards to the direction from which the cable approaches the termination. The cable shall be so arranged as to permit locating the last cable support close to the termination. This will avoid putting undue strains on the equipment terminals or the PAGE NO. 8 OF 9
terminal lugs on the cable. Usually, such terminal supports shall be located 600-900 mm from the equipment terminals. Terminal supports shall be so located that no sharp edges are made on the cable and no bend occurs in the taped portion of the cable termination. 3.4 Grounding of Cable Terminations 3.4.1 General Metal parts of terminating devices, concentric neutral copper, tinsel braid or other metallic shielding on stress cones in cable terminations shall be effectively grounded to the system ground. These various components usually are bonded together within the cable termination so that a single grounding connection serves to ground the complete termination. However, precautions must be taken to make sure that all parts of a termination requiring grounding are properly connected together. An exception is when, on occasion, the open end of a single point grounded section of circuit is terminated. Special provisions will be required to isolate the cable shield or concentric neutral from the ground potential of metal parts of the terminating rack or device. 3.5 Partial Discharge Measurement Partial discharge measurements shall be carried out for high voltage cable 230 kv & 380 kv at site after completion of termination of the cable to detect the weak points. The tests shall be carried out preferably during the HV test or immediately thereafter. 3.6 Elbow Terminations 3.6.1 When specified by the Design Engineer, elbow type separable connector terminations may be used to terminate 15 kv and 35 kv rated cables to compartment type padmounted transformer or padmounted switching cubicles. 3.6.2 All elbow terminations shall be rated 200 amperes for load break service and 600 amperes for no-load break services. 3.6.3 The elbow terminations shall be provided with a capacitive test point. 3.6.4 The application of elbow terminations shall be performed in strict accordance with the manufacturer's installation procedures. 3.6.5 All elbows shall comply with IEEE Standard No. 386. PAGE NO. 9 OF 9