Airgap Flux Probe detecting Short Circuit Inter-turn of Rotor

Airgap Flux Probe detecting Short Circuit Inter-turn of Rotor of Turbo Generator

Sparks Instruments SA, MC-monitoring SA , Switzerland

For Hydro Generators, Turbo Generator, Wind turbine, industrial Motors

airgap flux probe

The airgap search coil designed and manufactured by Sparks Instruments SA and is used to detect faults in the rotor winding insulation of turbo generators. The body is made from fiber glass and the sensing element is encapsulated within high temperature epoxy resin. AS many machine designs are different, the ASC sensor is typically designed especially for each type of the machine.

airgap flux probe

The probe is installed on the wedge within the airgap between rotor and stator and the integrated small high temperature cable allows and easy routing outside of the machine. The open wires allows to lay also the cable through the ventilation holes instead passing it through the endwinding section. The probe measure the variation of the magnetic flux created from each rotor coil. It withstand up to 2 Tesla and is designed to operate for more than 155 degree C. The high temperature signal cable can be permanently used for upt o 155 degree C. If longer signal cables than 10m are required, the probe is delivered with a signal driver.

Flux Probe Installation 1

flux Sensor Glued On The generator stator Wedge

sensor Cable Through Air Duct


The acquisition and monitoring unit UDL-8000 is to monitor the high voltage insulation systems. It is a multi-modular system wuth central CPU controller, arious different signal conditioning modules and sensor interfaces (upto 8 modules per controller) and application specific software package. They are used for acquisition, evaluation and monitoring of the rotor flux of turbo generators.

The rotor flux is measured by the ASC-2000 series flux sensor installed within the airgap of the generator. The Flux sensor are connected to this UDL-8000 unit. The module offers the interface for the reference sensor or reference source. Two flux sensors and five 4-20mA analogue inputs for the acquisition of the machine operation condition.

The system using the signal response of each rotor coil and compare it with the coil response of the coil from the opposite pole a partial short turn or complete short turn can be detected

Flux Probe Acquisition Unit


 The sytem can be integrated in one system and communicated to all the condition monitoring devices.

Flux Probe System Integration


Please see on the menu for Online Partial Discharge Minitoring System for further protection of your generator and motors. There is also the information on Insulation and Condition monitoring of High Voltage equipments