Psu (Power Supply Unit); Figure 2.1.14-1 Psu Front & Rear Panels - LG-Nortel ipecs Installation Manual

IPECS Release 5
Hardware Description & Installation

2.1.14 PSU (Power Supply Unit)

The Power Supply Unit (PSU) converts 100-240 VAC @ 50/60 Hz to -48V and 5V DC. The DC
voltages are connected to the back plane for distribution to modules installed in the Enhanced
Main Cabinet. Power is connected via the back plane connector on the PSU and individual
modules.
In most configurations, the PSU is capable of supplying power to a full cabinet of nine (9) modules.
However, current draw for the different modules varies greatly; PSTN, ISDN and some other
modules require about 5 watts each while a POE8 driving power to 8 phones requires 40 watts.
Designing a power source to deliver the maximum power to nine POE8 modules would create cost
penalty for most configurations. A simple rule of thumb is to limit the number the number of WTIM8,
WTIM8 and POE8 modules to 5 per cabinet. To calculate the precise current draw of any cabinet
configuration, use the Power draw chart in section 3.1.3.2. The total current required must be less
than the PSU capacity, 5.3 amps. If more than the PSU capacity, reconfigure the cabinet modules
or install some of the modules in a second cabinet with a separate PSU.
The PSU includes a DB9 connector for RS-232 communication with gateway modules for alarm
notifications.
As shown in Figure 2.1.14-1, the front panel of the PSU has:
•
Six (6) Status LEDs,
•
Alarm Switch – to activate local audio alarm via the buzzer,
•
Buzzer for local audio indication of alarm condition,
•
DB-9 RS-232 connector,
•
Power Switch,
•
AC Power Input,
•
Fuse.
On the rear panel, the PSU has:
•
a thirty-two (32)-pin back plane connector.
Figure 2.1.14-1 PSU Front & Rear Panels
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