Installation
Redundant Mode of Operation
In the Redundant mode of operation, both power modules share the load (that is, both modules supply power to all slots in the carrier). If one power module fails, the remaining power module assumes the full load of the carrier. Operation of the CO Power Unit continues, but it is recommended that you replace the failed power module as soon as possible. Do not remove a failed power module until a replacement is available. For instructions on how to replace a power module, see the Power Module Replacement Instructions section in Chapter 3 of this guide.
When the power modules are configured for Redundant mode of operation, up to four carriers can be mounted in a cabinet and meet the stated maximum temperature operating limits of 50°C. The reduction of carriers per cabinet is necessary to compensate for the loss of cooling capability if one of the power modules fails. If the operating temperature limit in the room is less than
45°C, then up to five carriers can be mounted in a cabinet. If the operating temperature limit in the room is less than 40°C, then up to six carriers can be mounted in a cabinet.
The ± 48 Vdc input can be provided in one of three power options:
•Using one ± 48 Vdc power source and one fused input power cable.
•Using one ± 48 Vdc power source and two fused input power cables.
•Using two separate ± 48 Vdc power sources and two fused input power cables.
The second power option is more reliable than the first power option because it protects the CO Power Unit against a short circuit failure in the input circuit of one power module from interrupting the power source to the other power module. However, the third power option is the most reliable for the Redundant mode of operation because it protects against short circuit and input power failures. For more information on these powering options, see the Providing Power to a CO Power Unit section. To change the mode of operation, see the Setting the Option Straps section.
Alarm Forwarding to a 6800 Series NMS
In order to send power module failure and fan failure alarm signals to a 6800 Series NMS, you must have a Modular 3611 DSU (configured to forward alarms to a 6800 Series NMS) and an NMS adapter cable.
(Model 3151 CSUs and Model 3161 DSU/CSUs do not support this feature.) When these components are properly configured and alarm conditions occur, alarm signals are sent to the 3611 DSU and then routed to the 6800 Series NMS where an alarm event is reported to the NMS operator. (Remember, you can also use a nonmodular Model 3611 DSU, but you must build your own adapter cable to connect Pin 9 of the EIA
Pin 19 of the EIA
For the Basic or Independent mode of operation, the Modular 3611 DSU (configured for alarm forwarding) must be installed in a different carrier in the cabinet (that is, a carrier in the cabinet other than the one you want to manage). This arrangement enables you to send alarms to the 6800 Series NMS even if one of the CO Power Unit's power modules fails. If the Modular 3611 DSU is installed in the same carrier, a power module failure will disrupt alarm forwarding to the 6800 Series NMS. In the Independent mode of operation, a power module failure disrupts service to
NOTE
In the Redundant mode of operation, you may want to install the Modular 3611 DSU (configured for alarm forwarding) in a different carrier in the cabinet in the unlikely event of a double power module failure.
For information on connecting the CO Power Unit to a 6800 Series NMS, see the Connecting the Alarm Contacts to a 6800 Series NMS section.
May 1998 |
