The wide availability and strong historical performance mean that electrical distribution and safety problems sometimes go unnoticed. Factory managers, however, still need to understand the risks of aging infrastructure and changes in facilities. Increasing this understanding, especially in the area of electrical grounding, is the goal of Geartech BR in this article. Keep reading!
Tension and its impact on security
Voltage and resistance determine the amount of current generated in a circuit. Higher voltage means more current. The chain is the source of damage to people and equipment. Three factors determine the level of damage: amount, path and duration of the current. Although no action can completely eliminate the risks, properly installed and maintained grounding can mitigate them and reduce the potential for injury, damage and expense.
A failed grounding system can be catastrophic at multiple counts, causing, among other things:
- Injury or death.
- Extreme damage to the equipment.
- Legal and financial risks.
How electrical ground fails
Grounding the equipment reduces the stresses induced in the metal parts of nearby power lines and distribution equipment, helping to prevent damage from arcing in buildings / structures. Therefore, any equipment with potential for static buildup requires grounding.
Static build-up develops due to friction from moving material and can occur in tanks, vessels and pipes. Wiring and electrical grounding help drain static electricity charges.
Electrical power systems, such as the secondary winding of a transformer, are grounded to limit lightning-induced voltage, line overvoltages, or unintentional contact with high voltage lines. Secondary lands also stabilize the return path for single-phase loads.
If the contact resistance of an electrode to earth is high, very little fault current can return through this path, and the circuit protection device may not open to eliminate a ground fault. Then, all metallic parts associated with the electrical installation – metallic piping and structural steel for construction – can stay and remain energized.
When plant personnel are evaluating an electrical grounding system, it is important that they remember that safe dissipation paths are determined, in part, by the composition and condition of the soil:
Composition: Clay, sand or stones in the soil increase resistance. Moist and clayey soil decreases. For example, soil that contains a high percentage of clay can be an insulator. Sandy soil is an insulator when dry, and clay soil can be a slightly better insulator.
Condition: Wet and dry cycles can cause shortness of breath in the soil, compromising contact with buried electrodes. Seismic activity, groundwater cycles or equipment vibration can cause conductor breaks or sand migration through the soil, resulting in collection around buried objects and changing contact resistance.
Electrical ground compliance programs
Think of electrical ground compliance as a way to save lives and equipment. Plants must establish grounding compliance programs and apply them with procedures that meet standard work rules, such as:
- Do not work on ungrounded equipment.
- Always work between terrains.
- Report known or suspected problems.
- Remove and reconnect the grounding elements when performing other work in the area.
- Keep proper records, even for portable land.
As with many systems, grounding faults are age related. The longer since an incident, the more likely a failure to occur, possibly leading to injury or death.
Geartech BR is one of the largest importers and traders of films, polyester compounds, papers and insulating tapes in Brazil. Contact us to know more about our services and products! It will be a pleasure for us!