Centrix City and Centrix City Compact vans are equipped with the latest generation of non-destructive cable diagnostic systems. These include an SPG 40 test set, which is a multi-functional system for testing, prelocation, pinpointing and burning of cable faults in low and medium voltage networks.
In the City van, this is partnered with an Teleflex T 30-E reflectometer, and all functions are easily managed from fully integrated control unit that provides testing, diagnostics and fault location on one screen. In the City Compact van, the SPG 40 test set is used in conjunction with a detachable Teleflex SX reflectometer to provide testing and fault location functionality. Diagnostic functions are provided via a laptop computer.
The systems in both vehicles have been designed to be easy to work with and they follow the Megger easyGO operating philosophy that enables even inexperienced users to efficiently carry out cable checks, fault location and diagnostics. Comprehensive safety features are also incorporated, with all safety-relevant parameters automatically monitored in line with current codes and standards.
Introduction
A great deal of attention is devoted to safe working practices relating to electrical construction, maintenance and repair work. Industry electrical publications regularly report on safety issues, including the use of the proper tools and equipment for energised and de-energised work, as well as using the correct personal protective equipment (PPE) for each workplace situation. However, electrical test instruments are given very little, if any, discussion in safety articles. Even the dangers of using the wrong test instrument or using an instrument improperly, which can have catastrophic results, are rarely mentioned.
Some of the most frequently used test instruments include non-contact voltage testers, multimeters, insulation testers and ground-resistance testers. A big issue with using non-contact or proximity devices, for example, is that to prove a circuit is de-energised it is necessary for that circuit to be tested phase-to-phase and phase-to-ground, which cannot be done using this type of tester.
When electrical safety is discussed, the subjects of shock, arc flash, and arc blast predominate in the discussions. The question is often asked: How do I identify when these hazards are present, or likely to be present, when I am using electrical test instruments on electrical circuits and equipment? This article discusses electrical hazards, along with requirements for assessing the workplace to identify electrical hazards, and also discusses personal protective equipment (PPE) associated with using test instruments.
Winding resistance testing is a very revealing electrical diagnostic test for the routine screening of power transformers to determine their “state of health”. In fact, it’s an essential test when dissolved gas analysis indicates overheating in the oil or of the paper, and no condition assessment is complete without it.
Moreover, if you were to ask experienced substation maintenance engineers for their thoughts about which electrical tests should be done on a routine basis (which is not necessarily the same, of course, as the tests they are actually doing!), the winding resistance test would be likely to take second place only to the transformer turns ratio (TTR) test.
The TTR test typically takes top honours, not necessarily because of its diagnostic capabilities, but because it provides validation and reassurance that the transformer is actually doing what it’s supposed to do - transforming voltage. Nevertheless, the DC winding resistance test would be a very strong contender for the top spot if the list of important transformer tests were ever re-ordered purely on the basis of diagnostic value and screening prowess.
For over 80 years Megger instruments have been sold in New Zealand and led the industry for all it’s testing and application needs. AVO New Zealand is proud to continue this tradition and is supporting the next generation of electrical apprentices.
*Discount from trade price. Full name and EW number of apprentice to be supplied at time of order placement
Nikola Tesla’s name is synonymous with pioneering electrical developments, and he is accepted as the originator of many devices – not the least of which is the AC induction motor – which we now take for granted. His inventions form the basis of much of the technology we currently use and although controversial, his life is now celebrated by engineers and history pundits alike.
