HV Testing

The HV test – commonly referred to as high-voltage testing and, in normative terms, part of electrical safety testing – is one of the most frequently implemented test tasks. It applies to practically every electrical product: PCBs and assemblies, power supplies and chargers, motors, transformers and coils, household appliances and power tools, luminaires, medical devices, control cabinets and switchgear, cable sets and connectors, as well as battery systems, inverters and electric drives. The required test is determined by the protective measure, not simply by the product’s voltage class.

The applicable product standard specifies the required test steps; MCF adopts the test voltages, limits and dwell times from the customer’s test plan. Typical steps include continuity and protective-earth testing with a high test current, high-voltage dielectric-strength testing against breakdown (AC or DC), insulation-resistance measurement, and touch-current and leakage-current measurement. Depending on the product, partial-discharge measurement, impulse-voltage and winding-short tests, or residual-voltage and discharge-time checks may also be required.

In series production, safety testing rarely stands alone. The high-voltage and insulation test is generally followed by the assembly’s electrical functional test (EOL test). MCF assesses case by case whether both can be combined on one test system, because test voltages, contacting, the safety concept and cycle time must be compatible. Where possible, one fixture, one test sequence and one shared report reduce the need for a second station and additional handling. Where combining the tests is not technically appropriate, they remain separate and their evidence is consolidated in the test database.

The safety concept forms the framework: a safety enclosure with monitored interlocking, dual-channel safety technology with an assessed performance level, safe shutdown and discharge, touch-safe contacting, unambiguous status indication, and clear separation of the test and operator areas. This enables high test voltages to be used at production cycle times without endangering the operator.