Rotating Machines

Partial Discharge (PD) testing and monitoring for stator insulation condition assessment

On-line PD Testing and Monitoring of Rotating Machines

Partial Discharges can occur at various points in the stator winding insulation of motors and generators, and can eventually lead to an insulation failure. Sources of PD include voids, delamination in the main insulation, slot discharges and various types of end-winding discharges. By PD testing and monitoring, the development of underlying defects can be detected and insulation condition of the stator windings assessed.


High voltage coupling capacitor (HVCC) can be permanently installed in the terminal box or high frequency current transformers (HFCT) sensors can be attached to the feeding cables at either the machine or remote end.

Test Equipment

In-depth diagnostic spot testing on in-service assets using the HVPD Kronos® Spot Tester using portable or pre-installed sensors.

Monitoring Systems

Continuous monitoring of complete electrical networks using our HVPD Kronos® On-line PD Monitoring System, and remote monitoring of rotating machines including Ex/ATEX rated motors.

Test Services

Comprehensive range of test services for on-line and off-line condition assessment, including offline turnaround service and reactivation services.