TALGIL COMPUTING & CONTROL LTD.
P.O.B. 775 Kiryat Motzkin 26119 ISRAEL
Tel: 972-4-8775948
Fax: 972-4-8775949
E-mail : talgil33@netvision.net.il
USER GUIDE
The frost protection controller is specially designed to protect the crops and the hydraulic
systems from being affected by low temperature. An analog temperature sensor connected to
the unit, enables continuous reading of the temperature between -10 and 60 Cº with a
resolution of 0.5 Cº. When the ambient temperature drops below the predefined set-point
Ton the irrigation is started and it will continue until the temperature raises above the second
set-point Toff at which the irrigation stops. When logically defined, the relation Toff >Ton is
expected, but even if by mistake the relation is inversely defined, the system will still execute
the frost protection referring to Ton as the set-point, below which the irrigation is active and
above which it is stopped. The controller needs no external powering, it is powered by two 9
Volt Alkaline batteries and it activates two wired 12v DC latching solenoid. Alternatively, if for
some reason the analog sensor can not be used, a dry contact thermostat can be utilized.
The system reports the currently measured temperature, the battery voltage, the current
status, the number of activations by the sensor and it also detects and informs about various
kinds of malfunctions.
THE CONTROL PANEL
The unit is equipped with an LCD display and two arrow keys. For energy saving purposes
the screen shuts off when the keys are not being used for more than a minute. Hitting any of
the arrow keys, turns the screen on again after a delay that may take 8 seconds. The main
screen displays the ACTUAL temperature and the two set-points Ton and Toff that can be
changed by the user.
Ton
01.0
ACTUAL
15.5
Toff
02.5
USING THE ARROW KEYS
ˆ
ˆ
Use the left arrow key
to move from one screen to another
In order to change the set-points Ton and Toff, the right arrow key
has to be
used. At the first touch, the cursor ▓ appears, blinking on the leftmost digit, which can
now be changed by using the left arrow. Use the right arrow again to move to the next
digit to be changed.
HALTING AUTOMATIC ACTIVITY
The system can be directed to halt automatic activity and to go into "FREEZE" state in which
the process will not start even if the actual temperature is below Ton. The actual temperature
will be displayed as usual and manual opening and closing of the solenoid is allowed. For
entering the "FREEZE" state and for exiting the FREEZE state, push both the arrow keys
simultaneously.
MANUAL ACTIVATION
The manual activation is intended for testing the solenoid. The Manual activation button is
located at the left side of the terminal board, see the drawing below. Keep the button pushed
and after a while, the solenoid will be activated. It will remain activated as long as the button
is pushed. Release the button and after a few seconds the solenoid will shut down.
USING DRY CONTACT THERMOSTAT
Optionally a dry contact Thermostat can be used in place of the analog temperature sensor. It
has to be connected to the terminals marked "CONT. IN" see drawing below. A few seconds
after sensing closed contact the process will start and it will remain active as long as the
contact remains closed.
Manual
activation
Analog sensor
input
+ IN GND
Two wired DC
Latching solenoid
NO- Black Green
NC- Green Black
Connection of the analog sensor to the FROST
FROST Analog temperature sensor
+
IN
GND
+18 v
OUT
GND
A three wired cable up to a distance of
30 meters makes the connection.
Dry contact input
for thermostat
Analog temperature sensor