Backup Battery; Backup Battery Charging Procedure - Motorola DIMETRA MTS 2 Installation, Configuration And Basic Service Manual

Backup Battery

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Backup Battery
The Power Supply Unit (PSU) handles the automatic switchover to a backup battery in the event
of AC power supply failure. The MTS charges a backup battery during normal AC operation.
The backup battery normally is located near to the cabinet.
This battery is connected to the DC connector on the front panel of the PSU through Junction Panel. Refer to
Chapter 4, "Hardware Installation"

Backup Battery Charging Procedure

The backup battery charging output voltage is 40.5 VDC to 57 VDC and output current 0 to 6 A.
A temperature sensor monitors the backup battery's temperature to ensure optimum charging.
Available charge current is reduced linearly with increasing temperature from 6 A to 0 A when
the PSU input air temperature increases from +30 °C to +60 °C
Charge voltage decreases with increasing battery temperature with the ratio of -72 mV/°C, starting
with 56.88 VDC +/-1% @ -10 °C and ending with 52.56 VDC +/-1% @ +50 °C
The PSU charges the backup batteries on the following conditions
(DC In Status LED is flashing fast (0.5 s) red-green):
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11-4
No Fan 2: Prevents Fan 2 alarm (and associated LED) when no Fan 2 is connected. If the Fan 2
becomes present during operation, the Fan 2 alarm circuit will automatically be reactivated;
No Fan 3: Prevents Fan 3 alarm (and associated LED) when no Fan 3 is connected. If the Fan 3
becomes present during operation, the Fan 3 alarm circuit will automatically be reactivated;
Fan Factor: Fan factor is used to determine automatically calculated Fan supply voltage -
the higher factor is specified the higher voltage is calculated. The Fan Factor range is 0.5 -
2.0 (by default 1.0). In systems with only one BR this factor is typically set to 1.0.
and
The recommended batteries to be used are a Valve Regulated Lead Acid (VRLA) recombination
type, with -48 VDC nominal. Such as Enersys Power safe VFT type.
Selected Operation Mode: AC Operation
Temperature range*: -10 °C to +50 °C
Battery Low Voltage start up: 40 V -5%/+1%
Battery Low Voltage Warning: 43 V ±2%
Chapter 5, "Interconnection and Internal Cabling"
Chapter 11: Power Supply Unit
for more information.
6802800U74-N September 2009