Long Life LL-M Mixed Dielectric Series

NEPTUNE-DUCATI Double Metalized Paper and Polypropylene technology (Mixed Dielectric) series LL-M for use in the power factor correction of Industrial & Office electrical networks is a series of quality products which has been designed to cater to the most demanding users where operating conditions are particularly critical and where reliability is of prime importance. The Long Life range also satisfies the demand for a product with durability features that are far superior to those provided by the usual metallized polypropylene technology presently in the market.

The capacitors used are characterized by the dielectric impregnated with a biodegradable synthetic oil. In this respect they differ from metallized polypropylene capacitors in which during operation, the air contained between the plates leads to the production of partial discharge which in turn cause the dielectric to age rapidly. Impregnation with oil as well as the total lack of air between the capacitor plates ensures that the dielectric-and hence the capacitor too-lasts a long time.

The dielectric consists of films of polypropylene and paper. The function of the paper is conduct the oil inwards to ensure that the dielectric is perfectly impregnated. Following a long period at a high temperature and in a vacuum, the impregnation treatment takes place in an autoclave. This ensures the elimination of all traces of humidity as well as the total absence of air between the capacitor plates thereby putting the dielectric in optimal conditions and granting the capacitor the longest possible life.

The capacitor are of the self-healing type with a very low loss dielectric. They combine these high-tech advantages with the safety and reliability of the traditional technology of impregnation used for Medium Voltage Capacitors. The capacitive elements are housed in a cylindrical container made of aluminium, equipped with an individual over pressure protection device

All of the materials employed are non-toxic and biodegradable. Thanks to the above characteristics, the capacitor has an expected life which greatly exceeds 2,00,000 hours. It is characterized by the capability of bearing high harmonic components up to R.M.S. Current level in excess of 4 In

LL- M Applications

In last few years there has been increase of non-linear loads like variable speed drives, UPS and computers in many industrial and Office electrical network. These non-linear loads generate current and voltage harmonics. P.F. improvement in these conditions become difficult as capacitors get overloaded because of harmonics and their application also may result in resonance conditions, making the condition further worse.

There is often felt a need of a very reliable P.F. correction capacitor which shall not only withstand high RMS current but also offer long operational life under sustained harmonics overloads. The LL-M modular series is best suited for this application.

It is recommended to used oversized capacitors in terms of Voltage in presence of a moderate Harmonic loads. Capacitor voltage to be selected for use in detuned filter circuits depends upon filtering factor of Reactors.

General Characteristics – LL-M Series