Regardless of the type of building you are in, electrical accidents are quite common at both offices and homes. Through electrocution, these catastrophic incidents cause hundreds of deaths and injuries in the United States. Fortunately, these unwanted encounters can be easily prevented by proper ground fault protection.
When the electricity in a live electrical circuit gets redirected to the ground instead of returning to the panel, a ground fault occurs. If someone comes into contact with ‘live’ exposed electrical wires or other exposed metal pieces linked to high-voltage equipment and appliances, he or she may get electrocuted. Hence, it is imperative to take proper measures and precautions to protect oneself from ground faults.
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Why Is It Important to Install GFI or GFCI Outlets?
To disconnect automatically in any occurrence of excessive currents, most electrical devices are fitted with fuses. However, this does not provide any protection when a normal current passes through an exposed metal piece or wire.
Electrical appliances use “earth” or “ground” cables instead. It is the third wire adjacent to the neutral and live wires in your standard cord that connects the exposed metal section of the device to the earth through a home wiring or a metal pipe.
In case of an exposed live wire coming in contact with any metallic parts, the current will be safely transferred to the earth via the ground cable. However, if the ground cable gets cut or damaged, there is a high probability of electrocution or other electrical hazards. The wires getting exposed is one of the most common electrical problems people often face, especially in old houses.
Therefore, as precautions, the electrical contractor uses protective components like ground fault circuit interrupters (GFCI) or ground fault interrupters (GFI) or residual current devices (RCDs). These devices stop any stray current automatically before they cause any accidents like electric fires. It is best to consult with your electrical contractor to decide between GFI Vs GFCI Outlets.
How Do GFCIs Work?
GFCIs or GFIs protect you against electric faults regardless of the wire being grounded or not. When a current leakage in the region of 4 to 6 milliamps is detected, they trip within 1/40th of a second, preventing electrocution.
It is recommended to hire a certified electrical contractor to install GFCIs and breakers on outlets in wet locations such as kitchens, bathrooms, and outdoor spaces like pools and hot tubs. The GFCI should also be installed in the garage, basement, and outdoor outlets, as well as other damp places where the outlet is placed 4-6 feet away from the sink.
The amount of current going through a device and returning along the electrical channel is continually monitored and compared by GFCIs. It trips as soon as a 5 milliamp difference is detected, functioning as fast-acting circuit breakers. The system can turn off electricity in 1/40th of a second, protecting you from electrocution.
How to Obtain GFCI Protection?
In a properly grounded electrical system, a ground fault will make the current flow back to the source through the equipment grounding conductor such as the metallic raceway that houses the circuit wires. It also causes the current to return to the source through the grounded metal pipes, structural steel, or other routes.
The impedance between the ground return path distribution system and other parallel pathways determines how much current is routed through the ground fault prevention system. Usually, ground fault protection is integrated into GFCI receptacles or GFCI circuit breakers for distribution system installation. However, there are some portable GFCIs that provide on-the-spot ground fault protection when it is not implanted on the circuit.
GFCI receptacles typically have a flat front with little black and red buttons between the plug slots. The receptacle can be configured to protect either a single receptacle or itself as well as additional receptacles and devices on the same circuit. On the other hand, GFCI breakers protect all receptacles and devices connected to the circuit against ground fault.
Optimization of Your Ground Fault Protection
You must remember that electrical grounding and GFCI protection are different from one another. GFCI does not require to be installed in a grounded circuit to function properly. A GFCI installed on a non-grounded circuit will not offer equipment ground or a genuine ground. As a result, this prevents surge protectors that require ground from functioning properly. On an ungrounded circuit, any receptacles or devices with GFCI protection must have a visible label indicating that the equipment has no ground. The labels are applied to new GFCI receptacles as stickers.
Ungrounded circuits are at risk of transient overvoltage as compared to grounded electrical systems. Intermittent or arcing ground faults might induce voltage buildup on the system, generating stress and insulation damage that might eventually lead to a voltages surge up to six times the normal equipment voltage.
Ungrounded circuits also make it difficult to find a ground fault because they do not allow ground-fault currents to pass through on the initial fault. Instead, they aim to keep the voltage on the faulted phase as low as possible throughout the distribution system.
Current-based ground-fault relays can pinpoint the exact location of the fault in grounded systems. These are in the following forms:
Phase to phase faults
These are short circuits that arise within the device as a result of burned wires caused by excess electrical current.
Three-phase faults
Three-phase faults are extremely uncommon, occurring in about 1% of incidents.
Ground faults
These make up 95% of all electrical faults.
Since currents must go back to their source, ground-fault relays can check phase conductors for any anomalies or read the current between the transformer neutral and ground for any inconsistencies. There are times when your ground-fault relay will trip by mistake.
This happens when the GFCI detects inaccurate fault current caused by harmonics and higher-frequency electrical noise, which is related to the usage of variable frequency drives, LED lights, inverters, and battery storage. Fortunately, accidental tripping can be avoided by selecting a high-quality ground-fault relay that can separate harmonic frequencies and other forms of noise from its current readings.
Final Words
Ensuring ground protection is one of the important electrical factors to consider when you are moving to a new site or building a new structure. Doing so will reduce the risk of severe shocks, electrocution, or fires. Install the appropriate GFCIs and make your surroundings safe.
