Instruction manual

UNDERSTANDING UPS OPERATION
Eaton
®
9390 UPS (20–80 kVA) and 9390IT (20-40 kVA) Installation and Operation Manual S 164201603 Rev 4 www.eaton.com/powerquality
7-15
An ABM charge cycle is initiated whenever one of these four conditions occurs since
the last charge cycle:
S The batteries have rested over the maximum rest time of 672 hours.
S Accumulated discharge time is over a maximum battery discharge time of
20 seconds.
S Battery voltage is under the opportunity charge level of 2.1 volts/cell and the
cabinet has been in rest mode for longer than 240 hours.
S An XCP command Initiate Battery Test is received.
7.3.4 Bypass
The bypass has a continuous-duty fully-rated SCR switch in the bypass circuit and a
contactor in the inverter leg. In Normal mode, the contactor connects the inverter to
the output. A backfeed contactor is also provided.
7.3.5 Batteries
The UPS operates from battery strings from 192 cells (384V nominal) to 240 cells
(380V/400V/415V/480V nominal).