Controller Failure Symptoms - Honeywell UDC2800 Product Manual

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 below.
Table 8-4: Controller Failure Symptoms
Upper Lower
Display Display
Blank Blank
OK Displayed
Output
disagrees
with
OK
Controller
Output
OK
OK OK
OK Displayed
Output
disagrees
with
Controller
Output
Display does not change when a key is pressed
Controller
Indicators
Output
Off None
OK Controller
Output
disagrees
with
OK
Displayed
Output
OK
OK External
Alarm
function
does not
operate
properly
OK Controller
Output
disagrees
with
Displayed
Output
Chapter 8 - Troubleshooting/Service
Troubleshooting
Probable Cause
Procedure
Power Failure 1
Current 2
Proportional
Output
Time Proportional 3
Output
Current / Time 4
Proportional
Output
Malfunction in 5
alarm output
Position 6
Proportional or
TPSC Output
Keyboard 7
Malfunction
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