Why Does Neutral & Ground Short Together in AC Circuits?

In summary, neutral and ground are shorted together in AC circuits to provide a safe path for excess current to flow, preventing damage to appliances and reducing the risk of electrical shock. This connection also allows for accurate measurement of voltage and helps to improve the overall stability of the electrical system. Shorting neutral and ground together is a standard safety practice that helps to protect both individuals and equipment in AC circuits.
  • #1
monus76
3
0
hi there
need help

i just need to know why ground and neutral ( A.C CIRCUITS) short together on the body of machine chassis or panels.i found this in one oil heating unit ,with high wattage of heating element.

who ever can reply ,highly appreciated

with thanks
 
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  • #2
It depends on when the installation was done. New installations should never have the neutral and ground hooked together except in the main service entrance. Any subpanel, disconnect for a furnace, air conditioner, etc. must keep the neutral and ground seperated. In the past, the neutral and ground were allowed to be shared or connected in subpanels. Search physics forums for this sort of thing. It's been discussed before.
 
  • #3
In low voltage systems, the three main grounding system are used as defined in IEC 60364:

- Exposed-conductive parts connected to neutral -TN-
- Earthed neutral -TT-
- Unearthed (or impedance-earthed) neutral -IT-

The purpose of these three systems is identical as regards protection of persons and property mastery of insulation fault effects. For choosing the best grounding system, it is important to know our requirements and resources.

For more information you can refer to Grounding riddle No.21 in http://electrical-riddles.com
 
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1. Why do neutral and ground short together in AC circuits?

Neutral and ground short together in AC circuits to provide a return path for current. In AC circuits, the neutral wire carries the return current back to the source, while the ground wire is used as a safety measure to prevent electric shock. When neutral and ground are connected, it ensures that any excess current will flow safely to ground instead of causing damage to the circuit or appliances.

2. What happens if neutral and ground are not shorted together in an AC circuit?

If neutral and ground are not shorted together in an AC circuit, it can lead to a dangerous situation known as a "floating ground." This means that the ground wire is not at the same potential as the neutral wire, which can result in electric shock or damage to equipment. It is essential to properly connect neutral and ground in AC circuits to ensure safety and proper functioning of the electrical system.

3. Can neutral and ground be connected at multiple points in an AC circuit?

Yes, neutral and ground can be connected at multiple points in an AC circuit. In fact, it is recommended to have multiple connections to ensure a low resistance path for current to flow to ground. This helps to prevent voltage imbalances and protect against electrical hazards.

4. Are there any exceptions to the rule of connecting neutral and ground in AC circuits?

There are some exceptions to the rule of connecting neutral and ground in AC circuits. For example, in some older homes, the neutral and ground may be connected at the main panel, but not at outlets throughout the house. This is known as a "bootleg ground" and is not considered a safe practice. It is always best to follow the proper wiring guidelines and connect neutral and ground in all AC circuits.

5. Can neutral and ground be connected in DC circuits?

No, neutral and ground should not be connected in DC circuits. Unlike AC circuits, DC circuits do not require a return path for current. Connecting neutral and ground in a DC circuit can create a dangerous situation and should be avoided. It is important to follow proper wiring guidelines for both AC and DC circuits to ensure safety and proper functioning of the electrical system.

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