Why do we use double earth for three phase machine and equipment?

The two parallel path is connected to two separate earth points. Thus the equivalent resistance of the two parallel path gets reduced and it offers low resistance path to the fault current. Thus the effective path resistance of the two parallel circuit gets reduced and it provides better reliable protection.

Why is double earthing necessary?

Some of the factories earthing is done with a single core bare copper wire or with an aluminium strip or with a copper strip in single line, but it is necessary to have a double line earthing, as an additional safety, if one wire is open the earthing path will be taken by the other line .

Why the earthing of equipment is necessary?

Earthing is used to protect you from an electric shock. It does this by providing a path (a protective conductor) for a fault current to flow to earth. It also causes the protective device (either a circuit-breaker or fuse) to switch off the electric current to the circuit that has the fault.

Why earthing is needed in welding?

Welding Machine Ground The purpose of connecting the equipment enclosure to ground is to ensure that the metal enclosure of the welding machine and ground is at the same potential. When they are at the same potential, a person will not experience an electrical shock when touching the two points.

What is the equipment earthing?

Equipment earthing is a connection done through a metal link between the body of any electrical appliance, or neutral point, as the case may be, to the deeper ground soil. The metal link is normally of MS flat, CI flat, GI wire which should be penetrated to the ground earth grid.

Can you use two welding machines together?

NO, there is no problem with 2 welders welding on the same piece of steel at the same time.

What is double earthing and why is it done?

The double earthing is done to ensure that at least one earthing will be in operation if the other earthing gets disconnected. The equipment must be earthed at the two distinct positions of the equipment. Also, with the double earthing the effective earthing resistance gets reduced because of the two parallel circuits.

What happens when one phase of a power system becomes earthed?

(iii) In case of one phase becoming earthed the voltages of the remaining two healthy phases to earth rise from their normal phase-to-neural voltage to fall line value (√3 times their normal value). This causes stress on the insulation of all the machines and equipment connected to the system.

What is earthing protection?

To have an earthing intact in case one earthing connection is broken by any unlike event. To have as low an earthing resistance as possible. This is basically to have additional and fail-safe earthing in all eventualities.

What are the two ways in which three phase system can be operated?

There are two ways in which three-phase system can be operated and they are: 1. Isolated Neutral or Ungrounded Systems 2. Grounded Neutral Systems. Way # 1. Isolated Neutral or Ungrounded Systems:

https://www.youtube.com/watch?v=DQw6w0iHVMQ