Sterlco M2B+ Controller - Manual (Page 42)

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5-11 Setting the Approach Rate
The controller is provided with a selectable up and down ramp to setpoint feature, located in
the secure menu. The time base is in minutes and is adjustable from off to 99 minutes in 1
minute increments.
Use the following procedure to enable the approach rate feature:
1. Press the Index button three times to access the Secure menu.
2. Press the Enter button.
3. Press the Index button until the display reads “Approach Rate.”
4. Use the Up and Down buttons to select the time period in minutes.
5. Press the Enter button to accept the value.
6. Press the Alarm Silence button to return to Running mode.
5-12 Level Input Operation (Water Units)
All level inputs have a three-second input suppression timer to prevent false input signals
caused by turbulent fluid. The level input has a menu selection for CONTROL or ALARM in
the Secure menu.
When the machine is started, the controller will determine if a high- or low-level condition is
present. If the water level is below the low-level mark, the fill solenoid is enabled, filling the
tank. Once the water level is above the high-level mark, filling stops, and the pump, cooling,
and heating outputs are enabled.
As the process fluid is circulated through the system, the fluid level may fall. The control
system will continue to function without interruption. If a low-level condition exists for more
than three seconds, the pump, cooling, and heating outputs are disabled while the fill solenoid
re-fills the tank.
The controller has a Water Fill Timer, which can be set in the Secondary menu. The timer
can be set to “OFF” or from 1 to 180 minutes. When it is set to off, there is no time limit for
the fill solenoid. When it is set to on, and the low level does not clear in the preset time, the
fill solenoid valve will turn off.
5-13 Adjusting the LCD Display Contrast
Potentiometer R82, on the controller main PC board, is used to adjust the contrast of the
LCD. The range of adjustment varies from completely off, where nothing is displayed on the
LCD, to fully on, where the display “blooms” and may not be readable. Adjust the
potentiometer to achieve an acceptable viewing condition somewhere between the two
extremes.
5-14 Adjusting the Auto Shutdown Temperature Setpoint
The controller is provided with an adjustable shutdown setpoint. The range is 90°F to 180°F
(32°C to 82°C). Use the following procedure to change the shutdown temperature:
1. Press the Index button three times to access the Secure menu.
2. Press the Enter button
3. Press the Index button until the display reads shut down temp.
4. Press the Up or Down buttons to select the new temperature.
5. Press the Enter button to accept the value
6. Press the Alarm silence button to return to the Running mode.