Temporary Overvoltage (TOV) Test Systems

Evaluate surge protective devices under temporary overvoltage conditions.

The HVEX Temporary Overvoltage (TOV) Test System, offered by Atlas Energy, applies controlled overvoltage conditions to assess the withstand capability of surge protective devices (SPDs). Temporary overvoltages can arise from ground faults, load rejection, resonance, ferroresonance, and transformer energization. The system supports laboratory evaluation of how protective devices respond to these conditions.

HVEX engineers the test arrangement to the specified application. The documented configuration is intended for single-phase and three-phase low-voltage SPDs and includes a dedicated TOV test module, supply transformer, and TOV source. Other test configurations are available for engineering review.

Key features

• Dedicated equipment for temporary overvoltage withstand testing.

• Configurable test arrangement based on the device and required test procedure.

• Integrated supply transformer and TOV voltage source.

• Compact laboratory configuration for manufacturers, test laboratories, and research teams.

Documented configuration

• Input supply: 220 V, 60 Hz.

• Supply transformer: three-phase, 12.5 kVA.

• Supply-transformer primary: 220 V, delta connection.

• Supply-transformer secondary: 127/220/380 V, wye connection.

• TOV transformer primary: 73/127/220 V.

• TOV transformer secondary: 1,200 V.

• TOV transformer rating: 5 kVA.

• Test current: specified relative to the SPD rating, with NH fuse limitation at 300 A; the applicable test setting is defined for the device.

• Test specimens: single-phase or three-phase low-voltage SPDs.

Test methods and applications

The manufacturer's datasheet references ABNT NBR IEC 61643-1 for TOV testing of surge protective devices. The required test method, voltage profile, device rating, and system configuration are confirmed during project specification.

Applications include SPD development, electrical withstand evaluation, product qualification, and laboratory investigation of temporary overvoltage response. Contact Atlas Energy with the applicable test procedure and device ratings to configure the system.

Technical documentation

Download HVEX Temporary Overvoltage (TOV) Test System datasheet (English, PDF)