OVERCURRENT RELAYS MCGG, 22, 52, 62, 82 ALSTOM

Section 1. DESCRIPTION The MCGG 22, 42, 52, 62 and 82 are single, two, three or four pole overcurrent relays, with separate measuring boards for each phase or earth fault input. The MCGG 53 and 63 are three pole versions, having their phase inputs combined onto one measuring board. Each pole of the relay provides a choice of four IDMT characteristics and three definite time characteristics. Additionally, each pole is provided with an instantaneous high-set element which can be disabled if not required. The seven versions of the relay covered by this manual are as follows : MCGG 22 Single phase with instantaneous element MCGG 42* Two phase with instantaneous elements MCGG 52* Two phase plus earth fault with instantaneous element MCGG 53 Two phase ( with polyphase measurement) plus earth fault with instantaneous elements MCGG 62* Three phase with instantaneous elements MCGG 63 Three phase ( with polyphase measurement) with instantaneous element MCGG 82* Three phase plus earth fault with instantaneous elements The rated current of the relay ( In) is either 1A or 5A and appears on the module rating label. The relay comprises a case and single plug-in module, which utilises either one or two 28 way terminal blocks. The module is designed with ease of assembly and maintenance in mind, with a switch mode dc-dc converter on a mother-board at the back of the module. This board carries connectors so that printed circuit boards carrying timing/ measuring circuitry which can derive IDMT and definite time characteristics can be plugged in. * Refer to AREVA T& D for manual applicable to MCGG 42, 52, 62 and 82 relays with the last four model number digits 0501, 0751 or 1001.