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The purpose of this paper is to investigate a reliable evaluator of arc re-ignition and to develop a numerical tool for accurate prediction of arc behaviour of low-voltage switching devices (LVSDs) prior to empirical laboratory testing of real products.

Two types of interruption tests have been carried out in the investigation of re-ignition evaluators. Arc modelling tool coupled with the load circuit has been developed to predict arc characteristics based on conventional magnetohydrodynamics theory, with special attention given to Lorentz force acting on the arc column and surface phenomena on the splitter plate. The model assumptions have been validated by experimental observation of arc motion and current and voltage waveforms.

It is found that the exit-voltage across the switching device and the ratio of system to exit-voltage at the current zero point are reliable evaluators for prediction of re-ignition. Where the voltage ratio is positive, instantaneous re-ignition does not occur. Further, the probability of re-ignition is very low if the voltage ratio is in the rage of −1.3 to 0.

It is observed that the voltage ratio can be considered as a reliable global evaluator of re-ignition, which can be used for various types of LVSD test conditions. In addition, it is shown that arc modelling allows a good prediction of the current and voltage waveforms, arc motion as well as the exit-voltage, which can be used to obtain the evaluator of re-ignition.

This paper describes a method of removing noise from time series data records whilst preserving salient features of short duration, such as sharp transitions and significant peaks. A practical example is drawn from fault‐current testing of circuit breakers, for which the scheme was originally designed. It is demonstrated that the clarity of signal traces can be improved while preserving important transient features. However, the approach is generic and based upon the entropy gradient detection method used in image processing. Local entropy is used as a criterion for selecting the degree of smoothing required, so that features of interest can be preserved. Algorithm modularity allows ready adaptation for specific needs.

TODAY's high‐grade foams provide airport fire‐fighting crews with the capability to rapidly knockdown and extinguish fires as a result of aircraft crashes or engine failure. Furthermore, the ability of foams to bring fires quickly under control ensures that the damage done to the local environment by harmful fumes is kept to a minimum. Here, Michael Clarke, of 3M Industrial Chemicals Group outlines the development of fire fighting foams and their applications, and discusses the merits of the US Military Specification, contrasting it with the recent International Civil Aviation Organisation's specification.

Teramel is the name given to a new synthetic‐enamelled winding wire which British Insulated Callender's Cables Ltd. have recently developed to solve problems set by a variety of electrical equipment.

These articles have been written with the primary object of fighting fires in Power Stations and mainly those that can occur due to outbreaks from leaking lubricating oil systems and transformer and switch gear units. But the methods and equipment outlined are similarly applicable to all oil fires and will be of interest to all industrial bulk users of lubricating and electrical oils. In this part, the author covers automatic methods and describes the “Mulsifyre” system in detail. In the second part, in our next issue, he will deal with Fire Pumps, Portable Appliances, and Extinguishing Methods using Carbon Dioxide, Foam, and Dry Chemicals.

This paper aims to present and define a factor to assess the severity supported along transformer windings when the transformer is subjected to a transient voltage waveform due a switching operation of a vacuum circuit breaker (VCB). This factor is identified as time domain severity factor (TDSF).

Since each of switching waveforms depend on the electrical interaction between transformer and the VCB, it implies that each of those combinations is characterized by a TDSF. To obtain the TDSF implies to manage two different models of the transformer under consideration. Firstly, a terminal model (black box model) of the transformer is built to compute the switching waveform at transformer terminals during VCB operation. Then, a detailed model (white box model) of the transformer is used to compute the internal transient voltage distribution along transformer windings.

A practical application of a power system consisting of a real transformer connected to a VCB is performed to show the sensibility of the TDSF coefficient.

Previous works found in the literature already consider the evaluation of the overvoltages in transformer associated to switching transient by coefficients, such as the frequency domain severity factor (FDSF). But this factor, as a global coefficient, could not assess the severity along windings to localize dielectrically weak points. Therefore, this paper overcomes this limitation proposing an alternative coefficient identified as time domain severity factor (TDSF).

To highlight the key‐role of macroeconomic management in a dysfunctional emerging market economy.

The analysis – focused on the particular case of Romania, where the transition to market economy is underway – relies on two basic hypotheses. According to the former, the reform programs implemented during the 1990s failed to take into account some fundamental correlations such as the one between reform measures and the real state of the economy (more specifically, the presence or absence of distortions). Another important correlation must exist between various types of macroeconomic policies, whether designed to trigger changes in the real economy (e.g. transfer of ownership, etc.) or aimed at securing macro‐stabilization. According to the latter hypothesis, overlooking such correlations will jeopardize both macroeconomic equilibrium and the soundness of future growth.

The data illustrating the evolution of Romania's economy during 1995‐2003 confirm the aforementioned hypotheses. Although the economy started growing at a fairly‐high rate after 1999, growth has been mostly immiserizing and hardly sustainable since. This outcome can be illustrated by using well‐known models such as Bhagwati's generalized theory of distortions and welfare and Mundell's approach of macroeconomic policies under imperfect capital mobility.

The use of the “immiserizing growth” concept in depicting Romania's economic evolution after 2000 is most likely an element of originality. The paper might be valuable for emphasizing the imperfections of the Romanian “government‐central bank” tandem.