SOLUTION

Following materials are required for plate earthing

(i) GI earthing plate – 60 cm × 60 cm × 6.35mm

(ii) Copper earthing plate 60cm × 60cm × 3.18mm

(iii) Earthing copper wire = 105 SWG or

(iv) Earthing GI. wire =8 SWG

(v) Earthing GI. pipe 12.7 mm dia (to take earth wire)

(vi) GL Pipe 19.5mm (to pour water around plate amp)

(vii) Salt and wooden charcoal (for moisture)

(viii) Funnel-To pour water

(ix) Nut and bolt-50 mm × 8mm (copper nut bolt for copper plate and GI nut bolt for GI plate)

(x) Cast iron cover 30 cm × 30 cm (to cover from top)

Alternate layers of charcoal and salt are used around the plate. The layers of charcoal shall be placed immediately over the plate, and thereafter, successive layers of salt and charcoal are laid to keep the surroundings sufficiently moist.