Honeywell UDC3500 - Setting Failsafe Mode; Carbon Potential, Oxygen and Dewpoint Algorithms; Table 4-28 Procedure for Setting a Failsafe Mode

Monitoring and Operating the Controller
240 UDC3500 Universal Digital Controller Product Manual 3/07
4.24 Setting Failsafe Mode
Introduction
You can set the Failsafe Mode to be Latching or Non-Latching.
Set Failsafe Mode
Table 4-28 Procedure for Setting a Failsafe Mode
Step Operation Press Result
1
Select Control
Set-up Group
Setup
Until you see:
Upper Display = SET
Lower Display = CONTROL
2
Select Failsafe
Function Prompt
Func
Loop 1/2
You will see:
Upper Display =
LATCH (Controller goes to manual and output goes to
failsafe value)
NoLATCH (Controller mode does not change and output
goes to failsafe value)
Lower Display = FSMODE
3
Select a value
or
To select a failsafe mode in the upper display.
4
Return to Normal
Display
Lower
Display
At power up, the output will go to the value set.
4.25 Carbon Potential, Oxygen and Dewpoint Algorithms
Introduction
Carbon probes can be used to control Carbon Potential, Percent Oxygen or Dewpoint
applications by configuring the Input Algorithm 1 for the desired type.
Most carbon probes consist of a zirconium oxide (ZrO
2
) sensor and a thermocouple (to
measure the temperature at the ZrO
2
sensor). These probes generally have four wires, two
for the ZrO
2
sensor and two for the thermocouple. The ZrO
2
sensor is connected to Input
1 on this controller while the thermocouple is connected to Input 2. Input 1 actuation is
automatically set to Carbon when any Carbon Potential Algorithm is configured, to
Oxygen when the Oxygen Algorithm is configured, and to Carbon when the Dewpoint
Algorithm is configured. The thermocouple in these probes is normally a K, R or S
thermocouple type. However, Input 2 can be configured for any input actuation for
applications where some other temperature sensor is used. PV Source in the Control Set
Up Group should be configured to IN ALG 1.
Instruments with Two Loops may use Loop 1 to control the Carbon/Oxygen/Dewpoint of
the oven while Loop 2 may use the temperature measured by Input 2 to control the
temperature of the oven. For this application, PV Source in the Control Set Up Group