Grounding vs. Earthing vs. Neutral

Hello

Here are two important things,

1-Neutral is the return cable for the current, (marked blue). In a one phase system, the current throw this is the same as in the phase leader. In a 3-phase system the current is the algebraic sum of the current in the phases. In a symmetrical load, the current is zero and the neutral is not needed.

The potential of the neutral is normally zero, but can differ some volts. It depends of the voltage drop in the cable between the fuse panel and the load.

2- 3- Ground and Earth, I think it is two names of the same thing. This is the safety cable for the equipment, (marked green or green-yellow). It is connected between the metallic part of the engine and the ground in the fuse panel. Normally no current will flow through it. But if there is an insulating fault, the current will flow through this cable to ground, not through your body if you touch it.

In to the fuse panel you have phase cables and neutral. In the fuse panel, the incoming neutral is splitted in neutral (N) and protected earth (PE). To the N-rail all N cables are connected and to the PE-rail all ground cables are connected. Between N-rail and PE-rail is a screw for connecting them together.

For measuring a insulating faulty, you loose the screw and measure the resistance between N and PE. Normally it should bee very high, several Mohms or infinite.

'Tis my understanding that neutral is white in North America.

The idea is that the best balance between safety and economics was to supply houses with 220 volts with a centre tap. Most things run off the 110 between one or the other sides and the centre tap. Then for added safety, the centre tap is connected to the buildings metal water intake or to a copper rod drive into the earth. (In north America we say that is the 'ground' rod, in England they use the term 'earth'.)

For high power consuming appliances like dryers and electric ranges, the heating elements can use the 220, otherwise the current would double and the wire gauge would be large (low number, big wire). Not only does the big wire cost more, but installing really fat wires is a pain and would not be fun in a house.

I have some confusion after reading some posts.

What should be the parameters to be measured b/w Neutral & Ground and what should be the ideal values:

- Should the resistance be very high (or infinite) b/w Neutral & Ground?

- Should the voltage be very low (or zero) b/w Neutral & Ground?

Thanks!

CORNSTOVES

IT SHOULD BE 6 FEET DEEP FOR PROPER GROUNDING.

THANKS

YEEEESSSSS Six feet deep minimum for earth ground. I agree. = Unfortunately some professional utility installations are not even close to six feet deep. Also check the screwed connection to be clean, tight, clear of corrosion and dirt.

Just to clear something up:

In the U.S. (except possibly in very rural areas) any grounding of the electric service to a grounding rod and/or water pipe is a redundant ground for safety purposes. The main ground for the service entrance panel is from the utility via their ground referenced neutral. The redundant grounds zero out any small potentials that arise in the utility neutral/ground from unbalanced loads in a single phase 3 wire 220-240 service or just from loads in the now very rare 110-120 service. The utility maintains the neutral at ground potential by grounding it at multiple points, all along the transmission path, on both sides of all transformers, right on back to the generators, but small (typically on the order of a volt or two) potentials would still exist at the end user due to the resistance paths to ground from that user's current sources, in spite of the fact that they use a much larger conductor than the redundant grounds.

If you are relying solely on a water pipe (water service or well) or grounding rod for your grounding, something is wrong and it can be very dangerous.

The main thing to remember is this:

Neutral - is a current carrying wire meant for the return path of the circuit.

Grounding - 1) For equipment bonding so that all pieces of the equipment have the same "lower" or "zero" potential.

Grounding - 2) Same as earth ground (see below.)

Earth ground - is non-current carrying wire use in case there is a break in the neutral wire. (it's use is primarily for safety.)

MidniteFighter

so u say earth and ground r same and no current pass through it . then why they give earthing wire to remove left remaining current from a transformer.

Quote "you say earth and ground r same and no current pass through it . then why they give earthing wire to remove left remaining current from a transformer."

I am having trouble understanding what you are asking. Can you re-state it? When you remove the voltage from a transformer there is no remaining current. It is gone. Could you be referring to capacitors?

Pl. refer the below link

http://cr4.globalspec.com/comment/449592