Cubicle Boards

All switch boards are manufactured with a combination of 1.6 & 2 MM CRCA sheet steel, free standing, extensible on both sides, totally enclosed, dust tight, vermin-proof cubicle, flush dead front and of modular construction suitable for 3 phase 415V, 4 wire 50 Hertz system. All boards accessible from the front or as shown on drawings and specified in the equipment data sheet, for the maintenance of switch fuses, busbars, cable terminations, meters etc. Cables capable of entering the board both from top as well as bottom. All panels machine pressed with punched openings for meters etc. All sheet steel passed through 7 tank rust removing process of degreasing, acid pickling, phosphating etc. The panels finished with powder coating of approved colour. Engraved plastic labels provided indicating the feeder details, and capacity and danger signs.

The boards shall accommodate air insulated bus bars, air circuit breakers, mccb’s, switch fuse units with HRC fuses, starters, necessary meters, relays, contactors etc. as required and arranged in suitable tiers. All breakers and switch fuses suitably de-rated taking into account specified ambient temperature and ruling temperature inside the cubicle. The switch board fully compartmentalised in vertical tiers housing the feeder switches in totally enclosed independent compartments. Each compartment self sufficient with switch unit, fuses, contactors, relays, indicating lamps and an inter-locked door with facility for padlocking.

Each switch or MCCB or ACB shall have provision for locking in the OFF position for life safety. Each feeder must terminate in an independent labelled terminal block. Strip type terminal block accommodating several feeders together is not acceptable. Pressure clamp type terminals suitable for aluminium wires may be used upto switches of 25A and cable lugs for higher ratings. All terminations shrouded in an approved manner. The entire enclosure shall meet with IS: 2147/1962. Feeder connections of solid insulated copper/aluminium wires or strips with bimetallic clamps wherever required and if insulated, the insulation able to withstand the high temp at the terminals. Internal wiring, bus bar markings etc. shall conform to IS:375/1963. Internal wiring shall have printed ferrules.

Main switch should be at an easily accessible height and the highest switch operating handle should not be over 1.85M from floor level. Cable glands shall form part of the switch board.

Bus bars three phase and neutral and of copper/ Aluminium as specified and shown on drawings and rated for a temperature rise of 35 deg C over the ambient temperature specified, (IS:8084-1976). Neutral bars may be of one half the size of the phase bars or as shown on drawings. The main horizontal bus bars of uniform cross section and rated for the incoming switch. The vertical bus bars for the feeder columns will be rated at 75% of aggregate feeder capacity and uniform in size. Bus bars and interconnections taped with PVC colour coded tape to prevent bar-to bar accidental shorts. Each bus bar directly and easily accessible on removal of the front cover. Bus bars totally enclosed, shrouded and supported on non-hydroscopic insulator blocks to withstand thermal and dynamic overloads during system short circuits.

INTERNAL SEPARATIONS OF ASSEMBLIES (FORM 1, 2, 3 AND 4) :

Switchboard can be provided with partitions according to Form 1 to Form 4. The form of separation according to the latest IEC - 61439 offers an internal protection of minimum IP2X or more.

Wiring:

The entire wiring is done with high grade bright copper annealed standard PVC or FRLS or HR FR insulated flexible wires. Control wiring is carried with minimum 1.5 sqmm Gray wire & CT wiring is done with 2.5 sqmm Gray wires. DC wiring is done with 2.5 / 1.5 sqmm white wire. All doors are earthed with the help of 1.5 sqmm yellow green wire.. Electronic Card signal wiring is done with 1 sqmm Shielded wire.

Cable Chamber:

Cable Chamber of adequate size is provided on the side of Each Vertical with sufficient no of Cable Tie bars. Each Terminal block is provided with the identification markers & feeder designation sticker. Control & Power TB’s are separated from each other.

Earthing:

Protective earthing provided as shown on drawings or as follows:

Phase Conductor	Protective conductor
upto 16 sqmm	equal size
16 to 35 sqmm	16 sqmm
over 35 sqmm	50% of phase conductor

In case of dissimilar materials the Protective Earth Conductor suitably sized for equal conductance.
Protective earthing of each switch connected to the earth bar.

Component Identification:

All the base plates are neatly mounted with necessary electrical components to ease the wire routings & PVC Trufs are provided. The component Identification stickers are provided both on the components & base plates.

Drawings :

Following Drawings are provided to the customer before starting the manufacturing of PCC/MCC of the panels.
a) General Arrangement
b) Single Line Diagram
c) Bill Of Material
d) General Notes/specifications
e) Control Circuits/ schemes

After manufacture & testing of panel as built diagram are provided.

Tests:

Following routine tests can be witnessed by the customer.
a) Dimensional Check
b) Bill of Material Verification
c) Functional Checks
d) Insulation resistance test
e) High Voltage Test 2.5. KV for 1 minute