Second input check 84, Heater current monitor check 84, Second analog input check 84 – Red Lion TCU User Manual
Page 92: Valve positioner check 84, Calibration 84
![background image](/manuals/409018/92/background.png)
Second Input Check
The Second Input Check applies to those models that have the Second
Analog Input (Remote Setpoint), Heater Current Monitor and Valve
Positioner options. Different signals are required for each option.
Heater Current Monitor Check
1. Apply signals over the range of 0 to 100 mA AC, 60 Hz to the terminals
labeled CT. The tolerance is 1% of full scale
±
1 LSD (10 to 100% of
range).
2. Calibrate the Heater Current Monitor if out of tolerance.
Second Analog Input Check
1. Apply signals over the range of 0 to 20 mA DC to the terminals labeled
Second Input, 4-20 mA+ and 4-20 mA-. The tolerance is 0.2% of full scale
±
1 LSD.
2. Calibrate the Second Analog Input if out of tolerance.
Valve Positioner Check
1. Apply signals derived from the resistor string as described in Valve
Positioner Calibration. The tolerance is 0.2% of full scale
±
1 LSD.
2. Calibrate the Second Analog Input if out of tolerance.
Calibration
When re-calibration is required (generally every two years), this procedure
should be performed by qualified technicians using appropriate equipment.
Equipment source accuracy of 0.01% or better is required.
The procedure consists of: applying accurate mV signals, setting the
thermocouple cold junction temperature, applying precision resistance and
measuring accurate mA currents, among others. Allow a 30 minute warm-up
period before starting this procedure. Do not use thermocouple wire at any
stage of calibration.
This procedure may be aborted by disconnecting power to the controller
before exiting the configuration mode. The existing calibration settings
remain in affect.
Note: After completing any of the calibration sequences, the controller defaults
the input sensor type to thermocouple type “J” (tc-j). Be sure to set input
sensor for proper type.
Configure Step 9 - Factory Service Operations (9-Fs)
Display
Parameter
Description/Comments
Code
Enter factor service
function code
48
Calibrate instrument
CAL
Millivolt Calibration
yes/no
Calibration required for both
RTD and TC input. If this
procedure is performed, the
cold junction temp and RTD
ohms calibration procedures in
turn must be completed.
CJC
Thermocouple cold
junction temperature
calibration
yes/no
Not required if only using RTD
input. This procedure can only
be performed AFTER an
accurate millivolt calibration.
rtd
RTD Resistance
Calibration
yes/no
Not required if only using TC
input. This procedure can only
be performed AFTER an
accurate mV calibration.
ANCL
Analog Output
yes/no
This parameter will not appear
if analog output option is not
installed.
2CAL
Second Analog Input
Calibration
yes/no
This parameter will not appear
if second analog input is not
installed.
84