SECTION  3 
TROUBLE  CONDITIONS 
INTRODUCTION 
NOTE: 
Refer  to  Figure  3 for  locations  of  Operator  interface  Panel  LEDs  and  keys. 
When  a System  Trouble  Condition  is detected  by  the  NDU,  the  condition  is indicated  by the  following: 
l 
Yellow  ‘SYSTEM  TROUBLE”  LED  on  the  interface  panel  is flashing 
l 
Tone-alert  is ON  steady 
l 
Annunciator  LEDs  may  illuminate  (if installed) 
l 
Alphanumeric  display  on  the  interface  panel  shows  the  following  message. 
I 
**TROUBLE** 
Press  <ACK>  to  review. 
ALARMS  =  0 
SUPERVISORY  =  0 
TROUBLE  =  1 
I 
The  interface  panel  has  a yellow  SYSTEM  TROUBLE  LED  which  lights  whenever  a trouble  is present  in the  system. 
When  a trouble  occurs,  the  LED  flashes,  the  tone-alert  sounds  steady,  and  a trouble  message  is  displayed  on  the 
alphanumeric  display.  The  trouble  LED  glows  steady  and  the  tone-alert  is  silenced  when  the  cTBL  ACK>  key  is 
pressed. 
When  Global  Acknowledge  is used,  and  the trouble  clears,  the  system  automatically  clears  without  user  intervention. 
After  approximately  60  seconds,  the  NDU  alphanumeric  display  should  indicate  a  normal  system,  as  shown  below. 
I 
1 
I 
SYSTEM  IS  NORMAL 
8:32:45  MON  7  DEC  92 
I 
When  individual  Acknowledge  is  used,  the  tone-alert  “re-sounds”  when  the  condition  clears.  The  cTBL  ACK>  key 
must  be  pressed 
twice 
(once  to  change  from  Alarm  Summary  to  actual  point,  and  once  to  acknowledge  the 
condition).  After  a delay,  the  system  alphanumeric  display  should  indicate  a  normal  system. 
GLOBAL  ACKNOWLEDGE  PANEL  OPERATION  DURING  TROUBLE  CONDITIONS 
l 
‘TROUBLE’” 
Press  (ACK)  to  review. 
ALARMS  =  0 
SUPERVISORY  =  0 
TROUBLE  =  1 
SYSTEM 
SUPERVISORY  SYSTEM 
POWER 
0  0 
ALARM 
SERVICE 
-  ACKNOWLEDGE 
ALPHANUMERIC 
DISPLAY 
YELLOW 
LED  (FLASHING) 
ACKNOWLEDGE 
KEY 
Figure  3 
Operator  Interface  Panel  Showing  Trouble  Condition 
15