Sparesplanning Page195 of 544
Option11C and 11C Mini TechnicalReference Guide
NTAK75 extended battery back-up unit
The batteries supplied with the NTAK75 have an average useful life of four
years, meaning the batteries are depleted to 80% of capacity, and backup time
is diminished. After this period of time the batteries should be replaced. For
more information refer to Option 11C and 11C Mini Fault Clearing (553-
3011-500). The mean time between failures (MTBF) of the NTAK75 without
batteries is 100 years at 25° C.
Table 6 0
Dimensions of NTAK75 and NTAK76 batteries
Card Length Width Depth
NTAK75 19” (480 mm) 11.5” (290 mm) 11” (280 mm)
NTAK76 12.25” (312 mm) 9.75” (250 mm) 6.25” (160 mm)