18
The A419 control functions
Set point (SP)
establishes the temperature value at which the equipment is switched on or
off, depending on the user selected mode of operation. Set point range is -30 to 212˚F or -34 to
100˚C (in 1-degree increments).
If Set point mode is set to cut-in, set point is the temperature value at which the control closes
the Normally Open (N.O.) contacts. If Set point mode is set to cutout, set point is the temperature at
which the N.O. contacts open.
Differential (DIF
) established the difference in temperature between the cut-in value and
cutout value. The differential is set relative to Set point and may be set from 1 to 30 F˚ or C˚ (in 1 –
degree increments).
Anti-Short Cycle Delay (ASD)
established the minimum time that the outplay relay remains
de-energized before the next on-cycle. The
ASD
does not allow the output relay to re-energize until
the programmed time delay has elapsed. The delay is activated when the control is first turned on
and every time an on-cycle ends. When the delay is activated, the LCD alternately flashed the senor
temperature and
ASD
. The anti-short Cycle Delay range is 0 to 12 minutes (in 1-minute increments).
Sensor Failure Operation (SF)
establishes how the A419 control’s output-relay operates
the equipment in the event of a sensor or sensor wiring failure. The user may select to run the
equipment continuously or to shut it down. When the control detects a sensor circuit failure, the LCD
flashes SF alternately with OP (if the sensor circuit is open), or
SH
(If the sensor circuit is shorted).
Before indicating a failure, the control implements a 1-minute delay, which allows verification of
failure condition and avoids nuisance failure indications.
Temperature Offset (OFS)
establishes a set secondary
Set Point
and
Differentia
l values
that may be invoked to control an application when a circuit is closed between the binary input (
BIN
)
and common (
COM
) terminals (and
BIN
appears on the display). See Figure 3. Offset range is 0 to
50F˚ or C˚ (in 1-degree increments). A typical application might use a switching time clock to invoke
night-setback temperature settings.
IMPORTANT:
Make sure the Touchpad Lock jumper is installed (unlocked) before
attempting to adjust the A419 control functions.
Changing the A419 Control Temperature Units
The A419 control is factory set to display Fahrenheit temperature. To change to Celsius, press
Up
and
Down
(arrows) simultaneously. Press them again to display Fahrenheit units. Verify that the
control is displaying the desired temperature units before setting the Set Point.