Technical specifications BT3 8.2.2.1. Busbars 8.2.2.1.1. Main Bus Bars

Busbar shall be 230/400 VAC +/-5%, 50Hz (3 phases +N+ PE), nominal current: 250A, Short Circuit Current withstand: 36kA. Busbar material shall be copper tin plated capable of carrying continuously a current of 250A as minimum as per the requirement indicated in Attachment 1 without exceeding the maximum temperature rise specified in the relevant standard. They shall be sheathed in high quality and marked with the phase colours. Busbar shall be completely isolated at the front, top, rear and bottom of the panel and shall have a continuous current rating. The minimum clearance in air between phases, and between phases and earth for the entire run of busbars shall meet the applicable standard. However, for busbars the clearance should be maintained even when the busbars are sleeved or insulated. Phase busbars shall have uniform dimensions without reduction. Neutral bus shall have uniform dimension same as phase busbars. Suitable tappings shall be provided for each outgoing feeder. Flexible bus shall be used for connection of the main circuit breaker to the horizontal busbar if its possible. All bolted bus connections shall be silver or tin plated. All exposed bus shall be insulated or taped. Holes or slots provided in wire ways or other metal members for routing of wires shall be provided with bushings or grommets. The design shall account for predicted thermal expansion and vibration. Connections between busbars and the equipment for a single circuit shall be sized for the highest current rating on the equipment itself. Bolts and clamps shall be provided with antiloosening systems. Busbar supports shall be made of non-combustible material to avoid internal arcs and surface discharges in the event of dust and condensation. All busbar joint shall be adequately protected against oxidation. Connections between bars and clips of circuit breakers parts shall be protected against oxidation by silver plating the clips and shanks of fixed parts. 8.2.2.1.2. Earthing bar

A copper main earth bar of cross section in accordance with the requirements of IEC 60439 shall run the whole length of the PDP-BT3 through the lower part and shall be drilled with holes for earth cable connection at each end. Each sector or compartment of the panel shall be effectively connected to the earth bar. Earth conductors flexible multi-strand shall be provided for the effective earthing of any hinged door to the main structure of the panel. Joints in the main earth bar shall be tinned and bolted with corrosion resistant plated bolts, nuts, and non-loosening washers.

8.2.2.2. Changeover switch

The changeover switch shall be supplied in accordance with IEC 60947-1, IEC 60947- 3, IEC 439-1, IEC 204-1 The changeover switch be equipped with door interlock handle. The changeover switch shall be of compact type, 230/400 VAC, 3 phases + N +PE , 50Hz, 160 A. Change-over manually operated switch shall be suitable for breaking and permutating two low voltage electrical circuits. Change-over switch shall be made by two standard switches mechanically interlocked. The changeover switches shall be mounted one on topofthe other makes this execution particulary compact and easy to connect to cables and busbars. 8.2.2.3. Feeder circuit breakers

Each outgoing feeder shall be protected for over current and short circuit MCCB/MCB. Incoming switch/circuit breaker shall have facility to isolate all three phases and neutral (4 poles). Feeder circuit breakers shall be supplied with thermomagnetic unit trip in accordance with IEC 60947. The short-circuit breaking of all feeder circuit breakers shall be equal to or exceed available short circuit current shown on Attachment 1. The nominal current of all feeder circuit breakers shall be in accordance with details mentioned in Attachment 1. Feeder circuit breaker operating mechanisms shall be designed and constructed as to allow the adjustment of the thermomagnetic trip unit setting. 8.2.2.4. Meters

The PDP-BT3 front door shall be equipped each one with: Three red indication lamps for the voltage presence, On/Off indication lamps, One inversion or absence of phase indication lamp. All the instruments to be assembled on the panel front of the assembly shall be flush mounted with rear connections; the case shall have preferably square or rectangular case and with the possibility of applying seals where necessary. 8.2.2.5. Pilot devices

The PDP-BT3 front shall be equipped with necessary pilot devices such as push buttons, indication lamps that shall be of the single unit, heavy-duty type according to IEC-60073. All pilot devices mounted on the front of the PDP-BT3 shall be labeled. a) Vendor shall provide Voltage Presence Lamp Indication for each phase. Indicating lamps must be adequately ventilated. Lamp holders must be attached to the panel by means other than the bezel. Lamps shall be 23mm LED cluster type and easily removed and replaced from the front of the panel manually not requiring the use of extractors. b) An emergency stop push button shall be provided to trip the main circuit breaker of the panel.

The emergency stop push button should be of the mushroom head latching type, with manual reset c) Vendor shall provide, within the power distribution panel Hand On/Off selector for each lighting circuit. 8.2.2.6. Terminal blocks / Cable entries

Terminal blocks for terminating power and control cables shall be segregated. Cable entry shall be from bottom. The location of cable entries shall be such that cable glands or cables, shall not obstruct access for connections to terminal blocks. Undrilled gland plate at least 3mm thick shall be provided at bottom of panel. Gland plate at bottom of panel shall be removable from top without approach from bottom. Not more than two wires shall be connected to any terminal. Spare terminals equal in number to 30% active terminals shall be furnished. Terminal blocks shall be located to allow easy access. Wiring shall be so arranged that individual wires of an external cable can be connected to consecutive terminals. Minimum size of power and control wiring shall be 2.5 mm. copper. Multi-tranded flexible copper wire shall be used for components mounted on doors. Wires shall be colour coded. Alternatively, PVC sleeves shall be used at both wire ends for identification. The panel shall be complete with power and control wiring up to the terminal block. 8.2.2.7. Wiring

The PDP-BT3 shall be front wired and front connected. The PDP-BT3 shall have a wireway running in adequate plastic ducts. Internal wiring shall conform to IEC 60439-1 standard. All cables within the panel shall be routed in a plastic ducts with covers. All wire connectors, except screw terminals, shall be of the anti-turn solderless type and shall be suitable for copper wire of suitable sizes in accordance with Attachment 1. The internal wiring shall be made with flexible PVC insulated copper cable 0.6/1kV. The minimum section of wiring cables shall be:

2.5 mm for voltage measuring circuits

4 mm for current measuring circuits All wiring shall be protected against contact with any sharp metal edges. Suitably sized cable lugs shall be supplied for termination of cables. All cables shall enter and leave from the bottom through a suitable cable gland mounted on removable gland plates and all terminals shall be clearly labeled.