Honeywell UDC 3500 Application Note

U U D D C C
U D
C
Controller Failure Symptoms
Introduction
In addition to the error message prompts, there are failure symptoms that can be
identified by noting how the controller displays and indicators are reacting.
Symptoms
Compare your symptoms with those shown in Table-1.
Upper Lower
Display Display
Blank
OK
OK
Displayed
disagrees
with Controller
OK
OK
OK
OK Displayed
disagrees with
First Current
OK Displayed
disagrees with
Second Current
OK Displayed
disagrees with
Third Current
3 3 5 5 0 0 0 0 A A
3 5 0 0 A
Table-1 Controller Failure Symptoms
Indicators
Blank Off
OK
OK
Output
OK
Output
OK
OK OK
OK
Output
Output
OK
Output
Output
OK
Output
Output
Page 1 of 16
p p p p l l i i c c a a t t i i o o
p p l i c a t i o
Controller
Output
None
Controller
Output
disagrees
with Displayed
Time Proportional
Output
External Alarm
function does
not operate
properly
Controller
Current Output
#1 disagrees
with Displayed
First Current
Output
Controller
Second Current
Current Output
#2 disagrees
with Displayed
Second Current
Output
Controller
Output
disagrees with
Displayed Third
Current Output
Revision 1
n n N N o o t t e e
n N o t e
Probable Trouble-
Cause shooting
Procedure
Power Failure
Current
Proportional
Output
Position
Proportional or
TPSC Output
Output
Current/Time
Proportional
Output
Malfunction in
alarm output
First Current
Output
Output
Third Current
Output
0
0
0
0
0
0
0
0
0