Power Supply Unit (Psu) - Theory Of Operation; Psu - Can Bus Monitoring, Alarms, And Controls - Motorola DIMETRA MTS 2 Installation, Configuration And Basic Service Manual

Power Supply Unit (PSU) - Theory of Operation

Power Supply Unit (PSU) - Theory of Operation
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Dependent on its configuration the MTS is equipped with one or two high efficiency switch mode Power
Supply Units (PSU). The PSU has a nominal AC input of 110 VAC/240 VAC (45-66 Hz) as well as a DC input
of –48 VDC. The PSU also has the capability to charge a 48 V backup battery during AC operation mode.
The PSU provides several DC output voltages to supply Base Radios, Site Controller, ATCC and Fans.
The PSU complies with the appropriate CE marking, EMC, EMI and safety requirements.
There is an ON/OFF switch on the front panel of the PSU module which con-
nects/disconnects DC output voltages.
The PSU operates in the following modes:
•
•
•
The MTS cabinet itself is wired to positive ground earth. The Power Supply Unit
has a floating DC ground concept.
For more information on PSU technical specifications please refer to
Specifications"

PSU - CAN Bus Monitoring, Alarms, and Controls

The PSU is monitored and controlled by the Site Controller. All monitoring outputs, alarm outputs,
PSU ID number and control inputs are available through a CAN Bus. It is also possible to update
the PSU firmware through the CAN Bus while the PSU is operational.
A unique identification of up to 4 PSUs is achieved by means of software. The assigned
ID is used to identify the PSU on the CAN Bus for commands and alarms. For more
information on CAN Bus, see
11-2
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DC only operation at -48 VDC (within -41 VDC to -60 VDC).
DC operation mode does not allow any battery controlling.
AC only operation at 110/240 VAC (within 90 VAC to 270 VAC) without battery charging.
AC operation (within 90 VAC to 270 VAC) and automatic switch over to DC
backup battery operation when AC fails.
Input Reverse Voltage Protection:
The PSU is protected from damage due to a reverse polarity input connection. If
the input polarity is reversed, the "DC In Status" LED will be solid red.
in Chapter 14, "Technical
Chapter 8, "Site
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Specifications".
Controller".
Chapter 11: Power Supply Unit
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"Power Supply Unit
6802800U74-N September 2009