Electrical Repair and maintenance works at Eklavya Model Residential School Parda Chundawat District Dungarpur

SITC of 11kV 630 Amps 21KA for 3 Sec. SF6 insulated, outdoor duty (IP54) , Extensible / Non extensible type Ring main unit (RMU) manually operated in combination of VCB modules and Load Break switch consisting of Copper busbar in SF6 insulated stainless steel Outdoor enclosure of thickness of 2 mm and tank of stainless steel Outdoor enclosure of thickness 3mm with manometer. The HV switchgear and control gear should be confirming to IEC-62271-100, IEC-62271-200-2003 & IEC-60694-1996. The RMU should be internal arc tested for 21KA for 1Second with IAC-AFL classification for both Cable chamber and gas tank as per IEC 62271-200 and LBS to be rated for class E3 as per IEC 62271 - 103. Vacum Interrupter should be same as used during type test of RMU. Each feeder of RMU should have voltage presence indicator. and VCB feeder should consist of 1 no. microprocessor based Self powered numerical relay with over Current/ earth fault & short circuit protection with each VCB feeder, 3 Nos. Protection CT shall be of Burden 2.5VA, ratio 50/1A, Class of Accuracy class 5P10 for O/C and E/F protection for each VCB. Load break switch feeder shall have Fault Passage indicator, Right angle boots for all the feeder Modules, Remote trip, Emergency Stop, Cable cover interlocking, Trasnformer protection tapo card etc. All the type test certificates as per IEC and CEA from Third party NABL / CPRI / ERDA accrediated lab to be submitted. (Cost of RCC Foundation / Steel Structure to be paid Extra)

Extensible 2 way RMU with 1 no. VCB & 1 No. Load Break Switch

SITC of IP-42 and general construction confirming to IS:8623 : 1993, wall/ free standing floor mounted dust and vermin proof compartmentalised cubical panel as specifications and Other parameters required as per point (a) ,(b), (c),(d), (e), (f), (g), (h) as below:-

(a) Thickness of CRCA sheet shall not be less than 1.6 mm upto 450 mm length/ width of any compartment and be 2.0 mm above 450 mm, load bearing structure shall be 2.0 mm thick sheet supported by base M.S. channel if required, cable alley compartments having concealed hinged type doors with key type lock with / without detachable extension type structure. Removable 3 mm. thick sheet steel gland plates with appropriate size of knockouts for cables shall be provided

(b) complete panel shall undergo a process of degreasing, Water rinsing, Activation, derusting, pickling in acid bath, phosphatising & shall be subjected to nine tank process and then Powder coated with approved shade of minimum 70 microns on both side(Inner & Outer side) of panel. The panel having PE foam/ Neoprene rubber gasket of not less than 3mm thickness ,required hardware , concealed hinged door with key type locking arrangement for equipment/switchgear earthed with 2.5 sq.mm braided copper wire.

[c) Interconnection between bus bar and switchgears /cable shall be rigidly supported and made out by flexible copper wires (up to 63 amp ) and by solid bus bar (>63 amp ) . control wiring will be carried out with 1.5 Sq.mm, Earth wire with 2.5 Sq.mm and CT with 2.5 sq.mm flexible copper wire only. All joints / interconnections of copper bus bar shall be dully tinned . Clearance between main bus bar and risers / metal parts shall be at least 10 mm additional to width of bus bar Bus bar is insulated by Heat Shrinkable sleeves . Earth and Neutral bus bar shall be half of the size of phase bus bar. ( Cost of Bus bar / Flexible wire for Interconnection between Main busbar and Switchgear is to be Paid Extra )

(d) Wiring between components within switchgear and Incoming / outgoing cable shall be done through the terminal block only. Direct connection shall not be permitted. Each terminal block shall be one piece moulded, barrier type, 650 volt grade, complete with washers, heads, studs with two nuts and identification strips and shall have adequate continuous current rating. For tap-offs, adjacent terminals with shorting strips shall be used. 10% Spare terminal blocks shall be provided. Wire identification on marking strip shall correspond to the designation of the wiring diagrams. All wire terminals on the equipment shall also be marked with designation corresponding to those of the wiring diagram.

(e) All wiring shall be enclosed in plastic channels and neatly bunched and closed in metering chamber, Wiring between terminals of various devices shall be ‘point to point’ (no wire splitting or tee connections) with wires neatly trucked along the back of the panels, adequately supported to prevent sagging.

(f) Floor mounted panel shall be mounted on Base frame of ISMC channel size 100 x 50 x 5 mm ( to be paid Extra )

(g) Tests: The insulation resistance (with 1000 V Megger) and High voltage Power frequency test (by applying a voltage of 2.5KV for one minute) shall be measured between phases, between phase and neutral and between phase and earth. both before and after high voltage power frequency test. The insulation resistance shall not be less than three megaohm. CT Secondary current injection test shall also be carried out.