Poor grounding not only causes unnecessary downtime, but it is also dangerous and increases the risk of equipment failure. Without an effective grounding system, we risk electric shock, not to mention instrumentation errors, harmonic distortion issues, power factor issues, and a slew of other potential intermittent issues.
If fault currents cannot find their way to the ground via a properly designed and maintained grounding system, they will take unintended paths, which may include people.
To ensure safety, the following organisations have recommendations and/or standards for grounding:
#OSHA (Occupational Safety and Health Administration)
#NFPA (National Fire Protection Association)
#ANSI/ISA (American National Standards Institute and Instrument Society of America) (American National Standards Institute and Instrument Society of America)
#TIA (Telecommunications Industry Association)
#IEC (International Electrotechnical Commission)
#CENELEC (European Committee for Electrotechnical Standardization)
#IEEE (Institute of Electrical and Electronics Engineers)
However, good grounding is used for more than just safety; it is also used to protect industrial plants and equipment. A good grounding system will improve equipment reliability and reduce the possibility of damage from lightning or fault currents. Electrical fires cost billions of dollars each year in the workplace. This does not include the costs of related litigation or the loss of personal and corporate productivity.
Grounding in substations serves several important purposes:
1. Safety: Grounding helps protect people and equipment from electrical faults by providing a low-resistance path for fault currents to flow safely into the earth, preventing electric shock hazards and minimizing damage.
2. Stability: Grounding assists in stabilizing the system during faults. It helps to maintain system voltage levels and reduce the risk of voltage fluctuations that could lead to widespread outages.
3. Fault Detection: Grounding facilitates the detection of faults by creating a reference point for detecting abnormal currents. If a fault occurs, the imbalance in current can be detected, allowing for quicker isolation and repair.
4. Lightning Protection: Substations are vulnerable to lightning strikes due to their exposed equipment. Proper grounding provides a path for lightning discharge, minimizing damage to equipment and reducing the risk of fires.
5. Electromagnetic Interference (EMI) Mitigation: Grounding helps control electromagnetic interference, reducing the impact of electrical noise on sensitive equipment and communication systems.
6. Static Discharge: Grounding prevents the buildup of static charges on equipment, which could lead to dangerous discharges.
Overall, grounding is an essential safety and operational measure in substations, helping to maintain the reliability of power systems and protect both people and equipment from the potential hazards of electricity.