MRI series

MRI reactors are used to limit the inrush peak current to less than 100 times the rated current of the bank of capacitors. The inrush current peak is due to the transitory phenomena of high amplitude and high frequency that are generated when the bank of capacitors cuts in on the supply network; this peak is considerably accentuated when a bank of capacitors is inserted in parallel with other banks that are already energized.

The reactors are single phase with an air core and copper winding and they are set in series with the bank of capacitors; they can be made for either indoor installation or outdoor installation. The reactors must be installed on post insulators with an insulation class equal to or greater than that of the bank of capacitors, considering the minimum distances for the installation indicated in the catalog.

The reactors must be chosen considering the following main factors:

• the sizing voltage must be equal to or greater than the network voltage;
• the sizing current must take account of the rated current of the bank and the current peaks;
• the reactor must be sized appropriately to withstand the dynamic and thermal stresses caused by the current peaks at the time of inrush;
• the influence of other banks of capacitors on the same network;
• the type of network in which to operate;
• the environmental conditions in which to operate.