Security providers face significant challenges when installing security equipment in high-voltage environments. Since utilities make up only a small segment of the security solutions market, many providers are not trained in appropriate installation practices in these areas. Consequently, they may inadvertently install security systems too close to electrical equipment, which can lead to high-voltage induction issues that cause harmful shocks to technicians and premature system failure.
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What is High-Voltage Induction?
High-voltage induction refers to a phenomenon where electrical voltages jump the air gap between high-voltage electrical equipment and other nearby objects, such as security equipment. It occurs when there is a difference in voltage potential between two conductive objects that are not electrically connected but are close enough together to allow for the flow of electric current through the air.
Though high-voltage induction anomalies are rare, they are typically seen at locations that are 230 kV or higher voltage. Known consequences of high-voltage induction issues include shocks from touching conductive surfaces, equipment failing prematurely and devices shorting out and catching fire.
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Why is it Happening?
Unless they are specialists, security system installers do not receive the same type of training as substation engineers, so they are often not aware of the nuanced best practices for substation environments. Currently there are no industry standards or factory specified guidelines in the security industry that address high-voltage interactions.
When setting up security equipment, an installer will often choose the shortest pathway to the end device location or the lowest cost pathway. However, this can lead to situations where security equipment is installed too close or parallel to high-voltage equipment, resulting in high-voltage induction.
As the experts in these environments, electrical and substation engineers should advise security installations to prevent high-voltage induction incidents.
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What Can Be Done?
There are a variety of ways to mitigate high-voltage induction issues, but the best option will depend largely on the location of the incident and the time and cost constraints of the utility. Below are a few potential solutions.
- Rethink cable routing, raceway path planning and conductive cable proximity
- Add current carrying isolators to the circuits
- Try shielding, grounding and isolation techniques
- Consider uninterruptible power supply systems, surge protection and voltage regulation mechanisms
- Choose field devices that are fed by fiber optic cables (nonconductive)
- Relocate the end device placement to a more suitable location away from high-side bus work
- Run a conductive conduit that is properly bonded to the station ground grid
- Install isolation surge suppressors on both ends of the conductive path
- Design pathways where the longest distance to device location is perpendicular to high-side bus work
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Looking Ahead
Don’t be shocked when it comes to high-voltage induction anomalies. As the electric utility industry applies more standards to increase security at substations, this phenomenon will become more prevalent. Educate yourself so that you can practice safe installation during your substation upgrade projects.
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Article originally published on the POWER Engineers website.Â