Adtran NIU3 User Manual

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4
Issue 1, January 2004
61175043L3-5A
P/N 1200657L2) that has a molded modular connector on one 
end and four soldered wire tips on the other (see Figure 3).
Figure 3.  Cable for the MX2800
Connect the soldered ends of the wires to the modular con-
nector that fits into the chosen power bus using a small slotted 
screwdriver. (The power buses are labeled A and B on the 
rear of the chassis.) Use the following wiring conventions 
(holding the connector as it will be inserted in the chassis):
Secure the ends of the wires and plug the connector into the 
chassis on the desired power bus (A or B). Connect the other 
end to the DC wiring harness of the PSU wiring harness and 
plug the AC plug into the AC power source.
Battery Backup Units
Mounting
When using the PS/BC in conjunction with available 
ADTRAN Battery Backup Units (BBUs), one of the 
following mounting options should be used:
Wallmounting the PS/BC (refer to Wallmounting on 
page 2).
Mounting the PS/BC to the product chassis containing 
the DC power supply.
Mounting the PS/C to the BBU.
Refer to your specific ADTRAN product system 
documentation to determine the optimal mounting solution 
for your system.
GROUNDING INSTRUCTIONS
For complete details on product grounding requirements, re-
fer to the Network Turnup Procedure in your product System 
Manual.
The ground connector on the PS/BC provides an additional 
ground reference (the third prong of the AC plug is also 
grounded) and may be connected to the “ground bus” or 
“ground wire” in a customer equipment room. 18 AWG or 
larger ground wire is recommended.
4. BATTERY BACKUP OPERATION
The following information is applicable when using the
PS/BC with any available ADTRAN BBU.
Alarm and Battery Disconnect Relays
Two relays support Power Supply operation:
Alarm  relay
Battery disconnect relay
Alarm Relay and Alarm Signal
The Alarm relay is provided for customer use. In normal op-
eration the contact alarm relay is open. If an AC power failure 
occurs and the unit defaults to the battery backup, the relay 
will cycle open.closed once per second (that is one second 
open then one second closed). The tolerance on this cycle 
time is 25 percent.
This indicates the battery is discharging in support of the 
load. If battery voltage decreases to 45 V the relay stays 
closed to indicate the battery is becoming depleted. The relay 
will open automatically when normal AC voltage is restored. 
Table 3 summarizes the alarm relay operation.
An alarm signal that cycles synchronously with the alarm 
relay is provided on the output cable. This signal, which is 
open during normal operation, cycles between open and 
ground during battery backup (as described for the alarm 
relay), and is ground when the battery voltage falls below 
45V.
Battery Fail Alarm
For battery backup systems that employ the optional Battery 
Test Assembly an alarm signal is provided to the PS/BC that 
indicates a failed battery (in need of immediate replacement). 
This signal is passed to the Alarm Relay and Output Alarm 
Signal. When a failed battery is detected, it is indicated by the 
Alarm Relay cycling open for 450 ms, then closed for 450 ms. 
Battery failure is also indicated by the output alarm signal 
cycling open to ground at the same rate.
Battery Disconnect Relay
The battery disconnect relay disconnects the battery pack 
from the system if the battery voltage falls below 40 VDC. 
This feature prevents damage tot he batteries. The batteries 
Left
WHITE
Battery Backup Alarm Wire
RED
Negative Terminal Wire
BLACK
Positive (RET) Wire
Right
GREEN
Ground Terminal Wire
GR-1089-CORE Requirement
An equipment grounding conductor that is not smaller 
in size than the ungrounded branch-circuit supply 
conductor is to be installed as part of the circuit that 
supplies the product or system.
Table 3.  Alarm Relay Operation
Condition
Alarm Relay
Normal
Open
AC Power Failure/Battery 
Backup engaged
Cycles open/closed 
once per second
Battery voltage is less than 
40V
Stays closed