Question { National Engineering Industries, 22774 }
How would we calculate the no of earthing pits required
for motor /panel
Answer
18. The GI conductor sizes shall be as listed below.
(1). HT switchgear, structures, cable trays & fence, rails,
gate and steel column
50 X 6 mm
(2). PCC & MCC EARTH PITS
50 X 6 mm
(3). DB
25 X 6 mm
(4). Motor rated above 55 KW & above
50 X 6 mm
(5). Motor rated above 22 KW & up to 55 KW
40 X 6 mm
(6). Motor rated above 5.5KW & up to 55KW
25 X 6 mm
(7). Motor rated up to 5.5 KW
8 SWG. GI wire
(8). Lighting panels & local panel
25 X 6 mm
(9). Control & relay panel
25 X 6 mm
(10). DG frame, excites
50 X 6 mm
(11). DG & TX’mer neutral
50 X 6 mm cu flat
(12). TX’mer body
50 X 6 mm
(13). Push button station
8 SWG. GI wire
(14). Receptacles & welding outlets
8 SWG. GI wire
(15). Lightning Arrestor
25 X 3 mm copper
(16). PLC & WF panels
25 X 3 mm copper