
COMSPHERE ±48 Vdc Central Office Power Unit
CO Alarm System Outputs
Both major (power) and minor (fan) alarms can be sent to the CO alarm system via the Alarm A and Alarm B output connectors. Figure 
The CO alarm system outputs are relay contact closures. Table 
| 
 | Table  | 
| Pin Assignments for the | |
| CO Alarm System Outputs | |
| 
 | 
 | 
| Pin Number | Assigned To ... | 
| 
 | 
 | 
| 1 | Major Alarm (power failure) | 
| 
 | 
 | 
| 2 | Major Alarm (power failure) | 
| 
 | 
 | 
| 3 | No Connection | 
| 
 | 
 | 
| 4 | Minor Alarm (fan failure) | 
| 
 | 
 | 
| 5 | Minor Alarm (fan failure) | 
| 
 | 
 | 
A contact closure is provided between Pin Numbers 1 and 2 to indicate a power failure. A contact closure is provided between Pin Numbers 4 and 5 to indicate a fan failure. Note that a major alarm signal is sent to a CO alarm system upon a failure in either the ± 48V input or low voltage output circuits, and that a minor alarm signal is sent if the fan speed falls below 1900 rpm.
CAUTION
The relay contacts on the CO Power Unit for the CO alarm system have a rating of
0.1amp maximum at 70 Vdc maximum.
| May 1998 |