Vertiv Liebert EXM2 - Number of Batteries; Battery Protection

7.5.2 Number of Batteries
The system battery cell number is 30 by default, and the cell float voltage is 2.27V. The number of batteries, EOD voltage, and
float charging voltage under the 380V/400V/415V voltage system are consistent, as shown in Table 7.2 below.
Pa ram ete r 380V /40 0V /415 V
Number of cells (standard) 180 ~ 264
EOD voltage 1.60Vdc/Cell ~ 1.90Vdc/Cell, 1.63V/cell recommended
Float charging voltage 2.2Vdc/Cell ~ 2.3Vdc/Cell, 2.27V/cell recommended
Table 7.2 R ange of am bient tem perature
7.6 Battery Protection
W A RN IN G! Users m ust choose approp riate sw itching devices to protect the battery from
short circuit an d overload, etc. It is recom m ended to choose the BCB box of Vertiv to provide
a m ore perfect solution.
The battery is connected to the UPS through the BCB. The BCB is manually closed and has electronic tripping device
controlled by UPS control circuit. If the battery adopts rack mounting or is far away from the UPS cabinet, the BCB shall be
installed as close to the battery as possible, and the wiring distance of the power and signal cables connected to the UPS shall
be minimized.
The BCB should provide:
• lsolation
• Short circuit protection
• In case of inverter locked by battery under-voltage, the switch automatically disconnects, avoid the damage of
battery over-discharge
• If equipped with a remote EPO button, can use the EPO button to remotely disconnect the BCB
• Protection of mis-operation
To obtain the required backup time, the batteries may be connected in parallel. In this case, each battery string must be
connected to a separate BCB.
N O T E: O nly properly trained p ersonnel shall maintain or op erate the BC B.
N O T E: B atteries are able to w ithstand an external short circuit under specific conditions and for a
specified duration. Fuses, circuit breakers and cab les m ust be selected in accordance to the battery
characteristics. Please contact Vertiv Technical Support for m ore inform ation.
N O T E: E xternal shorts can lead to irreversible b attery dam age and a reduced b attery service life.
W A RN IN G! In case of m issing or incorrect battery protection extensive dam age to the
batteries, the U PS, and ancillary equipm ent can occur.
7 Battery
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Vertiv™ Liebert® EXM2 UPS User Manual