The HV Tester 25 kV is a high-voltage generator with an infinitely variable negative DC output voltage of 0 - 25 kV.

The condition of the test object with regard to electrical strength and insulation quality can be determined on the basis of the unit's readings for output voltage and current.

The HV Tester 25 kV is used for:

Technical Features:

The T 99/1 High Voltage Test Unit is a powerful portable device able to generate a DC voltage of up to 40 kV.

The Test Unit 40 kV T 99/1 is used for:
testing the disruptive strength of cables, cable fittings, equipment and installations with max. 40 kV
locating high-impedance and intermittent cable faults in low and medium voltage systems as per the decay method in conjunction with a time domain reflectometer
converting high-impedance and intermittent cable faults into low-resistance faults (burning)

The shockproof enclosure of all high-voltage parts and the automatic discharging of the test object after shutdown / power failure ensure maximum protection for the operator. The short-circuit proof design and high output current of the T 99/1 40 kV test unit also make it suitable for cable fault location (Decay).

Salient Features of the T 99 / 1:

Sheath Tester MMG 5 is mainly designed for the withstand voltage testing of cable sheaths made of PE or PVC as well as for locating sheath faults on shielded plastic-insulated cables and the detection of earth-leakage faults in plastic-sheathed cables. In conjunction with Sheath Fault Prelocation Device MVG 5, sheath faults can be prelocated.

The following measurements can be taken:

Pin-Pointing is carried out by means of the Line-to-Earth Fault Locating Device ESG 80-2 using the method of measuring the step voltage. Due to the excellent burn down effect achieved by the full-wave rectification, this device is very well suited for converting high-resistance cable faults in low-voltage power cables into low-resistance ones. Moreover our new Sheath Tester MMG 5 has further special features such as:

The Sheath Tester MMG 10 is mainly designed for voltage testing of cable sheaths made of PE or PVC as well as for the location of sheath faults on shielded plastic-insulated cables and the detection of earth-leakage faults in plastic-sheathed cables. In combination with the Sheath Fault Prelocation Device MVG 5, sheath faults can be prelocated.

The following measurements can be taken with the MVG 5:
Sheath fault prelocation on shielded medium-high voltage cables.
Prelocation of line-to-earth faults on plastic-insulated low-voltage cables.

Pin-Pointing is carried out by means of the Line-to-Earth Fault Locating Device ESG 80-2 by measuring the step voltage. Due to the excellent burn down effect achieved by the full-wave rectification, this device is very well suited for converting high-resistance cable faults in low-voltage power cables into low-resistance ones.

Moreover our new Sheath Tester MMG 10 has further special features such as:

The TE PDS provides an inductive and a capacitive sensor for quality assessment on various electrical installations. The most common application for this instrument is to check the quality in terms of PD of joints and terminations immediately after installation. The TE PDS is used exclusively on insulated HV installations.

Detecting possible weakspots is done with the capacitive sensor, which picks up electric field changes due to PD. The intensity of the signal in pico coulomb decreases with increasing distance to the PD source and is immediately transformed into a dB-value and displayed. This change of signal level leads to the exact location of the PD.

The TE PDS is also applicable on shielded joints if the shield is grounded on both sides of the joint. This measurement uses the built-in inductive sensor. The course of the signal level along the joint indicates the exact location where highest level is indicated closest to the PD fault location.

PD pulses at the respective faults are reliabley detected and evaluated by the integrated VHF senors in the frequency range of 100 MHz. A high indication will provide higher reliability and quantification of the weakspot. The signal levels are indicated visually and acoustically.

Features

The oscillating wave test system OWTS is used to identify, evaluate and locate partial discharge (PD) faults in a cable insulation and in joints and terminations. The system can be used for of all types of medium voltage cables. Detailed information of the operational reliability of a cable system can be determined.
The test system can be installed either in a cable test van in combination with a modern, centrally controlled cable test and fault location system (e. g. Compact PD in a 3.5 t vehicle), or can be used as a stand-alone unit.

The cable under test is charged up in a few seconds to a pre selected peak value with a DC voltage. By closing the electronic switch the short circuit of the cable capacitance with the resonant coil leads to a sinusoidal oscillating wave test voltage. Depending on the capacitance of the test object, the oscillating frequency is fixed in a range of 50 Hz up to several 100 Hz.

The voltage level and the test frequency for the cable segment are close to the nominal service conditions, thus all measured PD activities can be effectively evaluated.
The oscillating voltage is only in contact with the test object for a few 100 ms and therefore nearly all long-term influences can be neglected.
Analysing the decrease of the test voltage, the PD extinction voltage can be determined easily. As a result, critical PD levels responsible for the future status of the cable insulation can be evaluated.

The OWTS unit is controlled by an industrial PC with an integrated data and signal storage ability. The system automatically evaluates the measured PD data and gives the user detailed information of the cable under test.

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 diagnosis of PE / XLPE cables applies for evaluation of an IRC measurement a software-module with neuro-fuzzy-extension. The intelligent multi-stage evaluation software take into consideration the special construction criteria of the test object and categorises the condition of the test object, including an anticipated maximum residual voltage level.

The software includes a database with automatic research for calculation of voltage withstand prognosis values according to data material of the standard DIN VDE 0276 as well as the protocolling of the diagnostic results.
The RVM cable evaluation is done using proven standardised factors and threshold values.

The opening of the electric power markets and new forms of asset management lead to the need to increase life cycles of installed energy components and to be more economic regarding existing underground installations. Using integral diagnostics, the cable operator has a valuable tool for non-destructive analysis of the cable network. This condition based maintenance makes planning easier whether to repair or replace an existing cable.