Technical Specification for Main 415V Switchboard 1. GENERAL

1 Annex B1 Technical Specifications Page 1 of 38 Technical Specification for Main 415V Switchboard 1. GENERAL a) The switchboards shall be of the indoor, metal clad, modular type suitable for operation in the switch room as indicated on the drawings. It shall be capable of operating in tropical and humid conditions. b) The switchboards shall be totally enclosed and constructed as described below. They shall comply with the requirements of the latest edition of EN 60439-1. c) The design of the Switchboard shall comply fully with Full type test requirements.

2 D) The switchboards shall be suitable for operation on 415 Volts, 3-Phase, 4-Wire, 50Hz system with solidly earthed neutral. Fault Rating The switchboards shall be designed to withstand a prospective fault level of 75 kA at 415 Volts 3 phase (symmetrical) for 3 seconds in accordance with the test procedures laid down in the EN standards. Construction a) The switchboards shall be naturally cooled, self-contained, metal-enclosed type, floor mounted, flush-fronted and suitable for front and rear access, bottom and top cable entry.

3 B) All structural works shall be adequately protected against corrosion. The basic materials shall be properly pre-treated before the final coats of resistant finishing paint are applied. c) Construction of the switchboards shall be minimally Form 3B separation as per EN 60439-1. d) The degree of protection for the switchboards shall be minimally IP 30 as per EN 60529. The floor shall not be considered as part of the enclosure. e) The partitions or barriers for internal separation of assemblies shall designed to obtain Form 3B separation of compartments shall comply to degree of protection IP 20 as per EN 60529.

4 F) The switchboards shall provide complete with all ACB, MCCB and other electrical components necessary for the correct operation and protection of the installation as described in this Specification and shown on the drawings. g) All operating devices shall be mounted for operation at the front of the Switchboard . Annex B1 Technical Specifications Page 2 of 38 h) The enclosure shall be fabricated from electro galvanized steel sheet with epoxy powder coating. The sheet steel thickness shall not be less than for structural member and for doors.

5 I) The front and rear covers of the Switchboard shall be hinged door type. Doors shall be effectively earthed to the fixed enclosure. All doors to be arranged to open through a minimum of 120 degrees, it must be possible to easily remove the door without disturbing other doors in the module. j) Compartment doors or cover shall be interlocked to prevent opening when the isolating device is in the "ON" position. The isolating device shall only be operable when the door is fully closed.

6 It must be possible to defeat the interlock for testing purposes once the door is open. Busbars and Connections a) The busbars shall be of plain hard-drawn, high conductivity, electrolytic copper bars in accordance with BS EN 13601 and of adequate rectangular cross-section to carry continuously the specified current without overheating and shall be rigidly mounted on non-hygroscopic glass fibre reinforced polyester so as to withstand any mechanical force to which they may be subjected under maximum fault condition.

7 B) All busbars shall be tinned and coloured red, yellow, blue, black and green at appropriate points to distinguish the phases, neutral and earth. No tapes shall be used. The main busbars should be located at the front upper lever in a horizontal plane and equally paced as specified in EN. All busbars system shall have short circuit rating of not less than 75 kA at 415 volts for 3 seconds. c) The busbar system shall be readily accessible for inspection, construction and maintenance duties without the requirement of additional equipment.

8 In case of a busbar short circuit, it shall be possible to clean or to replace the busbars and support system without stripping the assembly. d) In the busbar compartment the phase busbars may not be fully insulated. However, each phase busbar shall be able to withstand at least an applied AC test voltage of kV for a period of 60 seconds. e) The neutral busbar shall be the same size as that of the phase busbar. f) The earth busbar shall be provided internally throughout the full length of each Switchboard and shall be not less than 50mm X 6mm.

9 Secondary Wiring, Core Identification and Termination a) The conductor size shall be minimum with minimum 300V, PVC insulation. b) All control wiring shall be colour coded, carried out in neat, systematic manner and securely fixed by insulated cleats or approved method and arranged such that Annex B1 Technical Specifications Page 3 of 38 access to any apparatus or connection point is not impeded. Where inter-panel wiring passes through panel side sheets etc., the access hole shall be fitted with a suitable grommet.

10 C) Sleeve type identification ferrules shall be fitted on all wires at both ends. The sleeve or ferrules shall be of insulating material, which, except where otherwise specified, shall be white with black lettering and shall have a glossy finish. The sleeve or ferrules shall be unaffected by oil or damp. d) All control wire shall be separately terminated with tinned crimped lugs of approved type suitable for the terminal and wire use. e) Colour coding of secondary wiring shall be in accordance with IEC 446.