Procedure #8 - Analog Input; Table 7-12 Troubleshooting An Analog Input Failure - Honeywell UDC3500 Product Manual

7.7.8 Procedure #8 – Analog Input
Table 7-12 explains how to troubleshoot an Analog Input failure
Step
1 Check Input Configuration.
Check input wiring and external
2
resistor assemblies.
3 Check interconnection wiring
Check Input Signals.
4
Change the Input Type in order
5
to restore Factory Calibration.
Replace Input Board.
6
Replace Controller.
7
3/07

Table 7-12 Troubleshooting an Analog Input Failure

What to do
UDC3500 Universal Digital Controller Product Manual
How to do it
Check if the input configurations are correctly
set for the kind of sensor attached to the input
terminals. See Section 3.15 (Input 1) through
Section 3.19 (Input 5).
See the Input Wiring Diagrams in Section 2.7
and confirm that the instrument is properly
connected to the sensor.
Thermocouple, Milliamp, 0 to 10 Volt and –1 to
1 Volt input types all require that external
resistor assemblies be connected to the input
terminals. These are provided with your
instrument based upon the Model Number
ordered. See the Input Wiring Diagrams in
Section 2.7 for installation information.
If the actual sensor does not come directly to
the controller but is instead connected via one
or more intermediate junction panels, which in
turn are connected to the controller, then
check the continuity of the sensor to the
controller. Check the tightness of the screws
or connectors at the junction panels.
Turn off power to the instrument (more than
one switch may be necessary). Using a
multimeter, measure the actual signal present
at the rear terminals to ensure that it is within
the allowed input range as shown in Section
5.2.
See Section 5.6.
Installation instructions provided with new
board.
Troubleshooting/Service
327