Mobile test system for congested urban cables

Louise Davis

The new Megger Centrix City cable test van has been specifically developed to allow users to take advanced cable testing and diagnostic facilities right into the heart of congested cities, where access may be difficult for larger cable test vehicles. An aid for reducing downtime in low-voltage networks, the Centrix City is based on the Megger Centrix design, which allows all major functions to be accessed through an intuitive single-dial user interface.

Centrix City cable test vans provide single-phase connections for all HV operating modes, and three-phase connections for reflectometer measurements. According to their requirements, users can specify vans with VLF CR 40 or VLF CR 60 test systems, which work with cosine-rectangular test waveforms at a frequency of 0.1 Hz, or they can opt for the TDM 4540 test set that additionally offers sine wave VLF and partial discharge mapping using the damped AC (DAC) testing method. All of the options include extensive safety features that inhibit operation unless all connections, including earth connections, have been made correctly.

The Centrix City is available in three main configurations, fault locating only, testing and diagnostics only, or a combined version. For fault locating the chosen system is complemented by a Teleflex time domain reflectometer (TDR), which supports direct TDR operation as well as arc-reflection (ARM) techniques for accurate and efficient pre-location of a wide range of fault types. To ensure easy operation, even for inexperienced users, Teleflex TDRs provide automatic configuration, automatic cable measurement and automatic fault location. Full manual control is also provided for experienced users.

The results produced by the equipment on board the Centrix City vehicle are automatically loaded into MeggerBook Cable, an intelligent database software package that has been developed specifically for cable management applications. This ensures that valuable information is always securely stored and readily accessible. The results can be printed immediately, or saved in PDF format for subsequent archiving and export.

As well as the on-board test equipment, Centrix City vehicles provide convenient accommodation for connecting cables, which are located on readily accessible reels at the rear of the vehicle. These cables can be supplied in a wide range of configurations to match the user’s exact requirements.