167 of 222 pages
Operating and service manual
952
Power ref HI
Warning
Description
Controller Internal Voltage Reference Fault
Cause
Indication of controller internal voltage reference fault
Trouble
shooting
Possible causes:
•
Defect power supply for controller PCB.
•
Defect controller PCB.
Accompanied alarms:
•
There may be sensor alarms.
•
AL 801 will be activated during FT- or PTI test.
Trouble shooting:
1) Check if there are other active (sensor) alarms. Clear these alarms first
using their trouble shooting.
2) Check voltage level of 24V DC and 5V signals to see if power supply has
an open circuit or other damages. If voltages are ok, the controller PCB is
defect. Replace controller door.
Criteria
Reference ref below 2.75V DC
Controller
action
None
Log
X
Alarm
Alarm light
Off
Consequence
Elimination
Log data
Parm 1
Parm 2
Parm 3
Parm 4
Parm 5
Active/Inactive Low limit High limit
Actual value A/D channel
The measured voltage is internal on the controller PCB and cannot easily be measured