High voltage refers to an electrical potential large enough to cause sparking, insulation breakdown, or electric shock.
Definition of High Voltage
According to international standards, high voltage is typically defined as:
- Above 1000 V for alternating current (AC)
- Above 1500 V for direct current (DC)
In different industries, the threshold may vary. For example, in power transmission, high voltage is considered 1 kV to 35 kV, while extra-high voltage starts at 110 kV and above.
Where is High Voltage Used?
- Power transmission – Long-distance electricity distribution via high-voltage lines.
- Industrial applications – Operating large motors, transformers, and generators.
- Science and medicine – X-ray machines, particle accelerators.
- Transportation – Electric trains, trams, high-voltage batteries in electric vehicles.
Risks and Safety Measures
High voltage requires strict safety precautions:
- Insulation – Special materials prevent electrical breakdown.
- Grounding – Reduces the risk of electric shock.
- Warning signs – Mark hazardous areas to prevent accidental exposure.
The use of high-voltage networks requires regular maintenance, including high voltage testing. It helps to identify potential malfunctions, checks the insulation and guarantees the safe operation of the equipment. The main methods include dielectric strength tests, insulation resistance tests, and pulse tests. These procedures minimize the risk of accidents and extend the service life of the networks.
High Voltage Testing Equipment:
- Pulse reflectometers (TDR) – detect damage in electrical and fiber optic cables.
- Surge generators – create artificial arc discharges to accurately determine the location of damage.
- Megaohmmeters – measure the insulation resistance of a cable.
- High voltage AC/DC testers – check the cable‘s resistance to operating voltage.
- Thermal imagers – detect overheating and local damage in the connections.
- Diagnostic complexes for partial discharges – record the initial signs of insulation degradation.
