Cable Testing Equipment
The unique combination system for cable testing and cable diagnosis
Network operators can now get faster and significantly more reliable information about the quality and the condition of their cables. This is made possible thanks to the brand-new 50 Hz Slope Technology.
For the first time, it has become possible to immediately locate faults in underground cables during the actual PD measurement.
With the 50 Hz Slope Technology for the first time worldwide a withstand test with VLF cosine-rectangular voltage (VLF CR) and PD diagnosis with damped alternating voltage (DAC) is combined in one unit.
This allows an efficient and integrated solution for precise inventory of the network infrastructure. The important fact here is that the PD measurement data, gained with the VLF CR or with the DAC test voltage, can be compared directly with the 50 / 60 Hz network voltage.
Designed for the non-destructive testing of HV cables, these HV DAC systems use damped a.c. voltages to locate partial discharge faults in all types of power cables. The HV DAC offers advanced PD detection, site localisation and integrated dielectric loss (tan ∂) measurement as well as real-time analysis and reporting using Explorer software. The modular design of the HV DAC systems makes them relatively portable.
The PD level is measured in accordance with IEC 60270, there are adjustment features to optimise detection sensitivity and an automatic calibration mode with a joint location feature.
The control unit, a notebook, is menu driven, and the HV coil unit HV divider and PD analyser come in separate units while the HV source and switch are combined in the 150 kV unit and separated in the 250 kV unit.
The storage, analysis and evaluation of the PD signals takes place in the notebook and can be done either on site or in the office. The PD fault location is based on the time domain reflection method. For the PD diagnosis the test object is charged to the preselected peak value by a HV source within a couple of seconds and afterwards shorted with an electronic 150 kV, 200 kV and 270 kV switch via a resonance coil. Thus a sinusoidal damping AC voltage with low damping is created (DAC). Depending on the capacitance of the test object the AC frequency varies in the range from tens to hundreds of Hz. HVDAC series delivers state of the art PD measurement technology: live evaluation, localization and display of results.
Integral cable diagnosis for PE/XLPE/Paper
The portable combined CDS is used as universal dielectric diagnostic system on PE / XLPE insulated cables as well as paper insulated cables worldwide. It combines the known methods of Isothermal Relaxation Current measurement (IRC-Analysis) and Voltage Return Method (RVM-Analysis) for aging and deterioration diagnostics. Due to the low charging voltage of the measurement the CDS works absolutely non-destructive.
The PD Surveyor Air™ handheld PD surveying tool is the 'first-line of defence' for the detection of PD activity in medium voltage (MV) power cables and plant in the voltage range 6.6kV to 45kV. The robust test unit, incorporated with a digital TEV-dB display and external acoustic probes, enables the user to carry out rapid, "look-see" insulation condition testing through the unique combination of three PD measurement technologies: HFCT, TEV and Airborne Acoustic.
Optional accessories are available to improve both the flexibility and range of detection of the PD Surveyor Air™ unit. With help from the optional available outdoor acoustic parabolic receiver (incl. laser pointer) it is possible to detect and locate Surface and Corona discharges on e.g. insulators or outdoor terminations.
The Net Impedance Meter NIM 1000 is used for impedance measurements of LV distribution networks. At the connection point, the network is tested for its ampacity under real life conditions with currents up to 1000 A. Potential weak spots are made visible.
The NIM 1000 can be used for event-based actions (e.g. to determine the cause of unstable power conditions) or for preventive purposes (e.g. control measurements before or after net restructuring).
The Overhead Line Testing System has the purpose, to visualize impedance changes on overhead lines of any voltage level. Impedance changes can be short circuits, interrupts and their intermediate conditions, excessive tree growth etc. The overhead line must be de-energised and grounded for the measurement. During the measurement, the system ensures that all dangerous voltages and currents are safely discharged, without interfering with the measurement.
