P/N 1200657L2) that has a molded modular connector on one end and four soldered wire tips on the other (see Figure 3).
“ground wire” in a customer equipment room. 18 AWG or larger ground wire is recommended.
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):
Left | WHITE | Battery Backup Alarm Wire |
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| RED | Negative Terminal Wire |
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| BLACK | Positive (RET) Wire |
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Right | GREEN | Ground Terminal Wire |
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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.
An equipment grounding conductor that is not smaller in size than the ungrounded
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
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.
Table 3. Alarm Relay Operation
Condition | Alarm Relay |
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Normal | Open |
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AC Power Failure/Battery | Cycles open/closed |
Backup engaged | once per second |
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Battery voltage is less than | Stays closed |
40V |
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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
4 | Issue 1, January 2004 |
