SCOPE OF WORK (ELECTRICAL) - CIDCO Maharashtra Ltd.

CIDCO OF MAHARASHTRA LTD
C.A.No.03/CIDCO/EE(Elect)/2011-12 Sr. Page No.
4.3 All earth electrodes shall be tested for earth resistance by means of
standard earth test meter. The tests shall take place in dry months,
preferably after a protracted dry spell. If necessary, a number of
electrodes shall be connected in parallel to reduce the earth resistance.
In such a case the distance between two electrodes shall not be less than
twice the length of electrode.
4.4 The electrodes shall have a clean surface, not covered by paint, enamel,
grease or other materials of poor conductivity.
4.5 The exact location and number of earth electrodes required at each
location shall be determined in the field in consultation with the
owner/Engineer-in-charge, depending on the soil strata and resistivity, to
meet the ohmic values prescribed in clause 4.3.
4.6 The disconnect facility shall be provided for the individual earth pits to
check their earth resistance periodically.
5.0 CONNECTION :
5.1 All electrical equipment is to be doubly earthed by connecting two points
on equipment to main earthing ring. The earthing ring will be connected
via links to several earth electrodes. The cable armour will be earthed
through the cable glands.
5.2 The following shall be earthed.
1. Transformer neutrals (Double Earthing).
2. Transformer Housing.
3. All switchgear and their earth buses.