Motorola DIMETRA MTS 2, Installation, Configuration And Basic Service Manual

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MTS 2 and MTS 4 Installation, Con
fi
guration and Basic Service Manual Fans
The PSU stops charging the backup battery on the following conditions:
•
Internal PSU temperature: > 100 °C
•
Battery Temperature*: < -12.5 °C
•
Battery Temperature*: > 53 °C
*When a temperature sensor is connected to the battery and PSU. If the battery sensor is not
connected the battery will be charged with 54.24 ±1% VDC as if the battery temperature was 25
°C. The battery temperature monitored through CAN Bus will show 100 °C.
Fans
The PSU supplies fans, which are located in the fan trays under the module cage. For more
information on fans, see
Chapter 12, "Cooling Fans" . The PSU DC output voltage dedicated for
fans is 12 to 24 VDC and the output current is 1 A for each fan. Three fan connector outputs shall
supply three fan trays with two fans connected in parallel in each fan tray.
Fan supply output voltage can be automatically regulated as a function of PSU internal (ambient)
temperature and its output power. Fan supply output voltage can also be controlled by the CAN Bus in 7
steps from 24 V to 12 V. The highest value wins - automatic control versus CAN control.
At an ambient temperature below -10 °C the fans are stopped and restarted again at -8 °C. The fan
supply ramps up to 24 V output for a few seconds in all start up situations.
Power Supply Unit (PSU) - Indicators, Switches, and
Connectors
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This section lists and describes:
•
"PSU Indicators (LEDs)"
•
"PSU Switch"
•
"PSU Connectors"
Figure 11-2 shows the positions of indicators, switches and connectors on the PSU front panel.
6802800U74-N September 2009
11-5