Liebert Himod Operation & Maintenance Manual page 19

Analog Setup
For installation of analog sensors, see 4.5.1 - Connecting the Analog Sensors.
After selecting a compatible sensor and properly wiring it to the terminals, set up the control to mon-
itor the sensor as follows:
Slope. The slope is a multiplier used to scale the input signal. The slope can be positive (rising) or
negative (falling) and can range from 0 (resulting in a horizontal line) to ±999. The slope for a 0-5 volt
input is per 1 volt input, for 0-10 volt input is per 2 volt input, and for 4-20 mA is per 4 mA input. For
example, assuming an intercept of 0, for a 0-10 volt sensor input with a slope of 50, an input of 1 volt
would be displayed as 25: (1x(50/2)); 2 volts would be 50: (2x(50/2)); 3 volts would be 75: (3x(50/2)); etc.
Intercept. The intercept is an offset from point 0 corresponding to 0 volts or 0 mA input. The intercept
can be positive or negative and can be a point from 0 to ±999.
Adding an intercept of 100 to the slope example above, 1 volt would be 125: 100 + (1x[50/2]); 2 volts
would be 150: 100 + (2x[50/2]); 3 volts would be 175: 100 + (3x[50/2]); etc.
NOTE
For a 4-20 mA input sensor, if the desired reading at 4 mA input is 0, then an intercept of
-1 x slope would be required. For example, assuming a slope of 50, the formula would be
([-1 x 50] + 4 x [50/4]) = 0. The intercept is -50.
Text. You may enter a custom label for each analog input. The text label can be 20 characters in
length including any of the following: ABCDEFGHIJKLMNOPQRSTUVWXYZ#%*-0123456789, or
space.
Set Status Display
The Status Display can be set to display the return air temperature and humidity SENSOR READ-
INGS or the temperature and humidity control SETPOINTS through this selection. When SET-
POINTS is selected, the status display indicates so by displaying "SETPTS". If SENSOR READINGS
is selected, the Status Display will show the return air sensor readings.
Calibrate Actuator
For systems that use a valve actuator for chilled water dual cooling or GLYCOOL cooling, the actua-
tor timing may be calibrated or adjusted. This is the time it takes for the valve to travel from full
closed to full open. It is programmable from 0 to 255 seconds. The factory default time is 165 seconds
and should not be changed unless the actual valve travel time is not correct. The full valve travel time
is used by the control to determine the appropriate valve position. For example, if the valve travel
time is 165 seconds and 50% cooling is being called for, the valve will open for 83 seconds to acheive
50% open. To change the valve travel time, first enter the "CALIBRATE ACTUATOR" screen. The
display will show the present period used by the control for valve actuator full travel. Press ENTER
and adjust the time using the UP/DOWN arrows. When the correct time is displayed, press ENTER to
store the new time to memory.
Operation with Advanced Microprocessor Controls 11