Specifications

NLUO PMC CONTRACTOR

SIGNATURE AND SEAL SIGNATURE AND SEAL SIGNATURE AND SEAL

5. INTERCONNECTION B.B.C. & SWITCH FUSE, METERS :

For ratings above 150 Amps these shall consist of insulated copper strips to adequate section. For ratings below 150 Amps

PVC copper cable tails of appropriate size, terminating in tinned copper sockets may be used. The above are to be enclosed

either in sheet metal trunking or conduits so that no part is exposed.

6. DISTRIBUTION BOARDS :

These totally enclosed metal clad type Distribution Boards with hinged lids shall be in accordance with I.S. 2147-1952 and

2675-1966 and B.S. 214 and shall be welded construction and fabricated from rust proofed sheet steel and finished with

anticorrosive stove enamel paint and have provision for fixing on wall and having earthing terminals. Main Power DB shall be

free standing floor mounting type and branch DB shall be wall mounting type.

Power Distribution Boards (400 volts TPN) shall be constructed from 14 SWG sheet steel and Branch Distribution Board (230

volts SPN from 16 SWG sheet steel).

The minimum ratings of phase and neutral bus bars shall be 67% of the total ratings of fuse ways. Above 32 Amps Neutral

Busbars may be half the size of the phase Bus Bars.

The fuses shall be mounted on glazed porcelain supports of proper dielectric and mechanical strength. TPN suits should have

phase separation barriers between fuse N.L.U.Os.

Cables shall be connected to a terminal by crimped lugs.

Where two or more B.D.B.’s feeding low voltage circuits are fed from different phases of a medium voltage supply there

B.D.B.’s shall be installed at least two meters apart.

All three phase power distribution boards shall be properly earthed with two number 10 S.W.G. galvanized iron wires and

provided with suitable Danger Boards. All SPN B.D.B.’s shall be properly earthed with one number 10 SWG galvanized iron

wire each.

Branch DB (LDB) :

• The incomer to the LDB shall be terminated in a suitable rated TB (not directly on ELCB/MCB).

• The size of the DB shall have space for comfortable accommodate all MSBs, ELCB, TB and have space for minimum 2

no’s of spare MCBs.