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The electronic temperature control must be set for heating or cooling application by
placement of the mode jumper. Temperature setting is selected based on entering or leaving
fluid temperature control. Differential settings are selected to prevent excessive fan cycling
and fluid temperature swing.
Definitions
Control Functions
The A419 control allows the user to set a variety of functions using the keypad and
jumpers.
parameters, see the Adjustments section.
Keypad Programmable Functions
Setpoint (SP) establishes the temperature at which the equipment is switched on or off,
depending on the user selected mode of operation. Setpoint range is -30 to 212°F (-34 to
100°C). See the Cooling/Heating and Setpoint Modes section on page 22.
If Setpoint mode is set to Cut-in, the setpoint is the temperature at which the control closes
the N.O. contacts. If Setpoint mode is set to Cut-out, the setpoint is the temperature at
which the N.O. contacts open. Refer to Figure 9 and Figure 10.
Differential (dIF) establishes the difference in temperature between Cut-in and Cut-out.
The differential is set relative to Setpoint and may be set from 1 to 30F° or C. Refer to
Figure 9 and Figure 10.
Anti-Short Cycle Delay (ASd) establishes the minimum time that the fan remains off
before restarting again. The anti-short cycle delay is activated when the A419 control has
cycled the fan off. The delay does not allow the fan to be restarted until the programmed
amount of time has elapsed. When the delay is activated, the LCD alternately flashes the
sensor temperature and ASd. The anti-short cycle delay may be programmed for 0 to 12
minutes in 1-minute increments.
For example, if the anti-short cycle delay is programmed for 7 minutes, the control will not
restart the fan until 7 minutes after the equipment was turned off, regardless of the
temperature. During the 7-minute period, if the temperature reaches the cut-in setpoint, the
display alternates between the sensor temperature and ASd to indicate that the on cycle is
being delayed. After the 7-minute delay has elapsed, the fan is turned on, and ASd stops
flashing.
Note: A power interruption to the control will activate the anti-short cycle delay.
Figure 7, Anti-short Cycle Delay
20
•
Cut-in: The temperature at which the N.O. (Normally Open) SPDT (Single-Pole,
Double-Throw) output relay contact closes.
•
Cut-out: The temperature at which the N.O. SPDT output relay contact opens.
These functions are described below.
Direct Drive Fluid Coolers
For instructions on setting function
IOM 1062
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