PACKAGE : I Bid Document VOLUME : II - Public Health Engineering

Control at point of entry supply:
There shall be a linked main switch gear with fuse on each live conductor of the
supply mains at the point of entry. The wiring throughout the installation shall be
such that there is no break in the neutral wire except in the form of a linked switch
gear. The neutral shall also be distinctively marked. In this connection rule 33(2) of
the Indian electricity Rules, 1956 shall also be referred.
Installation of main switch gear:
The main switch gear shall be installed as near as practicable to the termination of
service line and shall be easily accessible without the use of any external aid.
Indication identifying earthed neutral conductors:
On the main switch gear, where the conductors include an earthed conductor of a
two wire system or a conductor which is to be connected thereto, an indication of a
permanent nature conductor. In this connection Rules 32(1) of the Indian
Electricity Rules, 1956, shall be referred.
Marking of apparatus:
When a board is connected to voltage higher than 250 volts all the terminals or
loads on the apparatus mounted on it shall be marked in the following colours to
indicate the different poles of phases to which the apparatus or its different
terminals may have been connected.
AC Three Phase : Red, Blue and Yellow
Neutral : Black
When four wire three phase wiring is done, the neutral shall preferably be in one
colour and the other wires in another colour.
Where a board has more than one switch gear, each such switch gear shall be
marked to indicate which section of the installation it controls. The main switch
gear shall be marked as such. Where there is more than one main switch board in
the building, each switch board shall be marked to indicate which section of the
installation and building it controls.
GTS : General Technical Specification. Page 123