repair maintenance of various electrical installations and mechanical equipments at kgit dtte bte at pitampura delhi sh replacement and retrofitting of breakers in existing sub station panel board.-supplying, replacement, installation, testing and commissioning of following capacity acb with pre fabricated factory made tested with suitable busbar, ics=icu=icw= 50ka for 1 sec, edo type microprocessorbased protection release with lcd 4 line display, frontoperated acb suitable for 415v and designed at 690vac supply system, adjustable over current, adjustableshort circuit, adjustable earth fault instantaneous protection and over temperature protection feature, the breaker shall have min breaking capacity of 50ka, 4no / 4nc auxillary contacts, ready to close contact, zone selective interlocking, double isolation feature, confirming to iec 60947 / is 13947, part-ii / 1993 protection release shall be self powered no additional power required for protection function, breaker shall have last 20 tripping detail memory with related accessories for each acb in case power failure operator can check cause of fault data on lcd display with date and time by connecting the battery module, new door as per new acbs also to be mount as existing panel breaking should have electrical interlocking ( incomer and bus coupler ) through under voltage release with proper wiring, retrofitting to match the acb with existing panel i / c buyback of burnt / worn out acb etc. complete as required at site. a ) 1000 a, 3 pole , 50 ka