Earthing DC Point

1. Instrument earth. Safety earth is just that, in the event the box get charged it has a path to ground and trips the breaker.

2. The maximum current of the supply will dictate the earth wire gauge to the ground bar.

2. The maximum current of the supply will dictate the earth wire gauge to the ground bar.

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3. Also the length of the earth wire, it's material construction & it's route (I.E. in the ground, through conduit or strapped to cable tray) will determin its gauge, in an ideal situation you should keep the distance from earthing ground bar to panel as short as possible & make sure you have good clean & tight connections.

1) Please do not get distracted with the terminology, you have to connect the negative wire strictly in accordance with the wiring diagram provided by the equipment manufacturer, dedicated terminal block and respective terminal number are there in the diagram as well as in the equipment manual.

2) As a safe consideration take fault duration to be one second, accordingly minimum crossectional area of conductor in mm square can be obtained by dividing system fault current with 214 in case of copper conductor or 160 in case of alluminium conductor.

as per NEC

ground wire size is dictated according to amp draw on either the load or service

<...2) Also how we calculate the size of Safety Earth wire ( From Panel to ground bar)...>

One uses British Standard 7671.