TABLE OF CONTENTS 1.0 PURPOSE 2.0 SCOPE 3.0 CODES, STANDARDS AND REFERENCES 4.0 ORDER OF PRECEDENCE 5.0 SYSTEM PARAMETERS 5.1 Frequency 5.2 System Voltage 5.3 Short Circuit Rating 5.4 Insulation Levels 6.0 DEVIATIONS PAGE NO. 2 OF 6
1.0 PURPOSE This chapter of the U/G Power Cable Transmission Engineering Standards (TES-P-104) is an introductory chapter to (TES-P-104). It provides general information applicable to underground cables and their applications to the system of Transmission Business Unit (TBU) of Saudi Electricity Company (SEC), Kingdom of Saudi Arabia. Chapters of TES-P-104 and the references therein serve as a guide to the Design Engineer. 2.0 SCOPE The U/G Power Cable Transmission Engineering Standards (TES-P-104): 2.1 Covers the following cable nominal voltage ratings: 2.1.1 Service (Low Voltage) Cables: 0.6/1 kv. 2.1.2 Distribution (Medium Voltage) Cables: 13.8 kv or 34.5 kv. 2.1.3 Transmission (High Voltage) Cables: 69 kv, 110 kv, 115 kv, 132 kv, 230 kv or 380 kv. 2.2 Reflects the use of the following types of cables and their applications: 2.2.1 Cross-Linked Polyethylene Cable (XLPE). 2.2.2 Low Pressure Oil-Filled Cable (LPOF). 2.3 Intended to help the Design Engineer in selection of the appropriate type and size of the power cable. 2.4 Contains the type of installation and the installation requirements in details. These are developed to govern the practices and procedures which shall be adopted by the Design Engineer for the design of underground cable systems. 2.5 Covers the drawings and ampacity tables in different installations cases and their requirements in details, which shall enable the engineers to design and install the power cables within the specified parameters. 2.6 Shows the various types and requirements of splicing and terminations of XLPE and LPOF power cables. However, it shall not cover the requirements for LPOF or XLPE cable termination at GIS cable boxes or at oil boxes at power transformers. 2.7 Serves as a guideline in selection of the single core power cable sheath bonding and grounding method of insulated metallic sheath of power cables. 2.8 The technical data provided in this standard (TES-P-104) for 0.6/1 kv, 13.8 kv or 34.5 kv are intended for general information. PAGE NO. 3 OF 6
2.9 In case of additional technical requirements, details or information not contained in this standard, the Design Engineer is responsible to have the cable system accurately designed. 3.0 CODES, STANDARDS AND REFERENCES 3.1 Items not specifically covered in this standard (TES-P-104) shall be in accordance with the latest revisions of the referenced Industry Codes and Standards. 3.2 It shall be the responsibility of the Design Engineer preparing the base design or detailed design to be or become knowledgeable of the requirements of the latest Industry Codes and Standards referred in TES-P-104. He shall bring to the attention of TBU of SEC, any latest revisions of these Codes and Standards which may have an impact on the technical requirements of TES-P-104. 3.3 Whenever different Codes and Standards are used, TBU of SEC approval to the same shall be obtained before proceeding with design. These Codes and Standards shall be equal to or better than those specified in TES-P-104. 4.0 ORDER OF PRECEDENCE In case of any conflict between various documents and standards or specifications for U/G power cable projects, the order of precedence shall be as follows: 4.1 The Scope of Work and Technical Specifications (SOW/TS) for the project. 4.2 Transmission Materials Standard Specifications (TMSS). 4.3 This standard (TES-P-104). 4.4 Other applicable Transmission Engineering Standards (TES). 4.5 Applicable Industry Codes and Standards. 5.0 SYSTEM PARAMETERS 5.1 Frequency The nominal frequency for SEC system is 60 Hz and the permissible operating frequency range is between 59.9 Hz and 60.1 Hz. The transient frequency variations shall be between 58.5 Hz and 61.5 Hz. 5.2 System Voltage The standard nominal system voltages adopted by SEC are listed in Table 01-1. The permissible operating voltage range is ± 5% under normal operating conditions and PAGE NO. 4 OF 6
± 10%, for 30 minutes, under emergency operating conditions. These are detailed in Table 01-1. Table 01-1: System Voltages Nominal System Voltage Voltage Range (Normal Operating Condition, ±5%) Voltage Range (Single Contingency Emergency Operating condition for 30 minutes, ±10%) (kvrms) (kvrms) (kvrms) 11 10.5-11.6 10-12.1 13.8 13.1-14.5 12.4-15.2 33 31.4-34.7 30-36.3 34.5 32.8-36.2 31.1-38 69 65.6-72.5 62.1-75.9 110 104.5-115.5 99-121 115 109.3-121 104-127 132 125.4-139 119-145.2 230 219-242 207-253 380 361-399 342-418 5.3 Short Circuit Rating The 3φ symmetrical interrupting (short circuit) current ratings of the various underground cables shall be as specified in Table 01-2. Table 01-2: 3φ Symmetrical Interrupting Short Circuit Current Ratings for Various Underground Cables Underground Cable Nominal 3φ Symmetrical Interrupting Voltage Rating Current (kv) (ka rms) 380 50/63* 230 50/63* 132 40 115 40 110 40 69 31.5/40* * It shall be specified by the design engineer. PAGE NO. 5 OF 6
5.0 Insulation Levels The insulation levels for all U/G cables shall not be less than the values specified in Table 01-3. For installations at an altitude higher than 1000 m, the insulation requirements shall be calculated by multiplying the insulation value indicated in the Table 01-3 below by the altitude correction factor as specified in IEC 60694 & IEC 60071-1. Basic lightning impulse insulation levels (BIL) are specified with respect to a standard 1.2/50 μs wave shape and the basic switching impulse insulation level (BSL) is specified for a 250/2500 μs impulse. Nominal System Voltage Table 01-3: Insulation Levels Basic Insulation Level (BIL) Power Frequency Withstand Votage *Dry/Wet Basic Switching Impulse Level (BSL) (Kv rms ) (Kv Peak) (Kv rms ) (Kv rms) 69 350 160/140-110/115 650 275/275-132 750 325/325-230 1050 460/460-380 1425 620/620 1050 *Dry for 1 minute, wet for 10 seconds 6.0 DEVIATIONS 6.1 The Design Engineer who prepares the SOW/TS for the U/G power cable project is responsible to obtain an appropriate waiver from TS&SD for any specific deviation from this Standard (TES-P-104). This waiver shall be taken for over-specification as well as under-specification. 6.2 In case of any deviations from this Standard (TES-P-104) during the Base Design and detailed design of any U/G power cable project, it is the responsibility of the engineer preparing the base design or detailed design to obtain appropriate waiver from TS&SD before finalizing the design. 6.3 Any cases of conflicts or deviations which cannot be resolved shall be referred to TS&SD who will be the final authority for correct interpretation of the standards and associated documents, as applicable. PAGE NO. 6 OF 6