Instruction manual

Total Access 850 System Manual Section 5 DLP-16

2. Alarm relay contacts are open during normal operation. The alarm relay contacts close in the event of

a local alarm condition or the receipt of an alarm from the T1 Carrier.

3. In a carrier alarm condition such as a Red, Yellow, or Blue (unframed all 1s), various alarm contacts in

the PSU close.

4. Carrier alarm conditions cause the Total Access 850 to initiate trunk processing. The following chain of

events then occur:

• MJ will be directly shorted to MJR.

• MJV will be directly shorted to MJVR.

5. Contacts MJ and MJR can be overridden manually during an alarm condition by pressing the ACO

pushbutton on the PSU faceplate.

6. If the 3-Amp power fuse on the PSU trips, the -48 ALM relay will close, providing a -48 VDC signal on

that pin. This alarm cannot be overridden by the ACO pushbutton. Refer to the table below for alarm

notifications.

Alarm Condition Relays Activated

MJR MJVR -48 ALM

RED ALARM X X

YELLOW ALARM X X

AIS ALARM X X

PSU POWER FUSE FAILS X X X

ALARMS ACO

DEACTIVATES

X X

Note: ACO will not deactivate MJR after a power fuse

failure.