Latest HV Testing & Maintenance Articles

Dielectric voltage testing verifies insulation strength via hipot, withstand voltage, and leakage current limits, ensuring electrical safety, IEC/IEEE compliance, and quality assurance across power systems, switchgear, transformers, cables, and consumer electronics.   How Dielectric Voltage Testing Works There are two standard methods from ASTM International: D877, Standard Test Method for Dielectric Breakdown Voltage of Insulating Liquids Using Disk Electrodes, and D1816, Standard Test Method for Dielectric Breakdown Voltage of Insulating Oils of Petroleum Origin Using VDE Electrodes.VDE stands for Verband Deutscher Elektrotechniker—the Association for Electrical, Electronic, and Information Technologies— a German standards organization similar in function to the Institute of…

Calibrate test equipment to ensure accuracy, traceability, and compliance in electrical labs using ISO 17025 procedures, NIST standards, and metrology best practices for multimeters, oscilloscopes, power analyzers, and signal generators.   Principles of Calibrating Test Equipment You’re serious about your electrical test instruments. You buy top brands, and you expect them to be accurate. You know some people send their digital instruments to a metrology lab for calibration, and you wonder why. After all, these are all electronic — there’s no meter movement to go out of balance. What do those calibration folks do, anyhow — just change the battery?…

Hipot testing checks electrical insulation strength by applying high voltage to confirm there are no current leaks. It is essential for ensuring safety, detecting faults, and preventing electrical failures in power equipment, cables, transformers, and other high-voltage systems.   Basics of Hipot in Electrical Engineering Also known as dielectric withstand, hipot testing applies high voltage to confirm that insulation can endure operating and surge conditions without breaking down. This test is crucial across various industries, including medical devices, automotive electronics, and aerospace systems, where insulation failure can pose life-threatening hazards. Companies that fail to conduct a proper dielectric strength test…

Circuit breakers are among the most important protective devices in an electrical power system. Their primary responsibility is to safely interrupt fault current, protecting personnel and equipment. Although breakers may remain closed for years, they must operate quickly and reliably when needed. A breaker can carry normal load current without problems, but that does not guarantee successful fault interruption. Mechanical wear, deteriorated contacts, insulation defects, and control circuit failures can develop over time. Testing during commissioning, maintenance, and following significant faults helps identify these conditions. Understanding Circuit Breaker Testing Circuit breaker testing evaluates the contacts, insulation system, operating mechanism, and…

Reclosers play an important role in distribution system reliability by detecting fault conditions, interrupting current, and automatically restoring power when a fault is temporary. Modern recloser controls can include overcurrent protection, automatic reclosing, voltage and frequency protection, cold load pickup, sequence coordination, communications, and other functions. Because of these capabilities, testing a recloser involves much more than simply verifying that it opens and closes. A typical recloser system includes the interrupter or “upper,” current and voltage sensors, control cable, and controller. Testing should consider how these components work together to measure system conditions, apply the programmed protection logic, and issue…

The Dielectric Voltage Withstand Test applies high voltage to verify insulation strength. It ensures transformers, wiring, and switchgear resist breakdown, helping prevent electrical hazards and confirming compliance with essential safety standards.   How the Dielectric Voltage Withstand Test Improves Electrical Safety The Dielectric Voltage Withstand Test is a critical safety procedure that every industrial electrician should be familiar with. This procedure, also known as a hipot test or high potential test, evaluates the effectiveness of electrical insulation in preventing potentially dangerous voltage breakdowns. By understanding the principles and applications of this procedure, industrial electricians can ensure the safety of electrical…