Having Idea on electrical faults is essential while studying on electrical engineering. If we can able to identify and understand the type of faults can occur it’s really easy to minimize the hazards of these faults and reduce to risk of it.three common electrical faults mainly can occur are
- Short Circuit Electrical Faults,
- Open Circuit Faults
- Overload Circuit faults
Following are some brief details of these kind of faults under electrical industry.
A short-circuit is an abnormal low-resistance connection between two nodes of an electrical circuit that are meant to be at different voltages.
This results in an excessive electric current .The Short Circuit is a more serious reason for a breaker tripping.
A short is caused when the supply wire touches another supply wire or touches a neutral wire. And there are other condition’s are may also cause to the short-circuit interconnection.
It can also be caused if there is a break in a wire in the circuit.
Shorts are a bit more difficult to diagnose because they can be caused by the wiring in your home or in something you have plugged into an outlet.
Damage form short circuits can be reduced or prevented by employing fuses, circuit breakers, or other overload protection, which disconnect the power in reaction to excessive current.
How to Identify Short Circuit fault
• Confirm that power is off at the outlet into which your device is plugged.
• Inspect your power cords for damage or a melted appearance.
• Check your outlets and plugs for the smell of burning or brown or black discoloration.
• Check the insulation on the wires to make sure it is not cracked and touching a black and white wire together.
• If you do not find the problem, repeat the process for all the outlets in the circuit.
Open Circuit Electrical Faults
A circuit is said to be OPEN when a break exists in a complete conducting pathway. Although an open occurs when a switch is used to de energize a circuit, an open may also develop accidentally.
To restore a circuit to proper operation, the open must be located, its cause determined, and repairs made.
Sometimes an open can be located visually by a close inspection of the circuit components. Defective components, such as burned out resistors, can usually be discovered by this method.
Others, such as a break in wire covered by insulation or the melted element of an enclosed fuse, are not visible to the eye.
Under such conditions, the understanding of the effect an open has on circuit conditions enables a technician to make use of test equipment to locate the open component.
Overloaded Electrical Fault
An overloaded circuit is the primary reason for a breaker tripping and occurs when a circuit is has more connected electrical load than it is supposed to have.
When more current runs through the circuit than the circuit was intended to take, the circuit breaker is designed.
Circuit breakers come in different ratings that determine how much current they will allow to flow through the circuit.
If a 15 Amp circuit breaker is protecting a 15 Amp circuit, and 20 Amps of current start to flow through it because a hair dryer, TV and small personal heater were all connected to the same circuit and were on at the same time then the circuit breaker trips to prevent overheating of the circuit.
How to Fix Overloaded Circuit Trips
• The most probable reason the breaker tripped is that you simply have too much plugged into one outlet or multiple outlets connected to one circuit.
• For example Move lamps, heaters, irons, hair dryers and other heavy power consuming devices to a different circuit not being heavily used so Turn off some of the devices on the circuit to reduce the load.
• Loose connections are another possible but less common cause.
• With power off, check outlets for a loose wire and the electrical service panel supply connected to the circuit breaker to see if it has become loose
• If these suggestions do not solve the problem you may have a more serious problem such as a Short Circuit or Ground Fault.
Hope you have some idea about the types of electrical faults can occur in electrical engineering industry.
A Ground Fault condition exists when the Earth wire touches the ground wire (bare copper) or the side of a metal outlet box (because the metal box is connected to the ground wire. The ground fault is a type of short circuit. This ensures that all exposed conductive surfaces are at the same electrical potential as the surface of the Earth, to avoid the risk of electrical shock if a person touches a device in which an insulation fault has occurred. It ensures that in the case of an insulation fault a very high current flows, which will trigger an over current protection device (fuse, circuit breaker) that disconnects the power supply.
How to Identify Earth Fault
Same as Short Circuit you have to also check that supply is not touching the side of the metal outlet box or the ground wire.
Necessity of Earthing
• To provide safety to personnel and equipment.
• To maintain a voltage in healthy phases in the event of a fault in one phase.
• To protect equipment and buildings from lightning.
• To serve as a return conductor in communication and traction works