Detail 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
MCGG 62* Three phase with instantaneous elements
MCGG 63 Three phase ( with polyphase measurement) with instantaneous
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
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.