Description Of The Controller; Operation Of The Controller - TECH ST-21D5 User Manual

Description of the controller

SENSOR
TEMPERATURE T1
or T2
Main screen: selection
of temp. T1 view
Edition: plus button
Manual operation:
turning the pump on
Main screen – pressing
and holding standby
button
When alarm is on –
muting the sound
Manual operation:
exiting manual
operation

Operation of the controller

ST-21D4 controller is of multi-purpose type equipped with two
temperature sensors.
The task of the controller is to start the pump if the temperature
difference of sensor exceeds a set value (T2-T1 ≥ Δ), where T2 ≥ then
minimum threshold of the pump. Will disable the pump when the T2 ≤
T1 or T2 < minimum threshold f the pump - 2 ° C (constant hysteresis).
where:
T2-temperature of the boiler
T1-temperature of the boiler (buffer)
Doing so, prevents unnecessary pump operation and unwanted cooling
down the tank when the temperature drops, which cause electricity
saving and prolongs the life of the pump. This increases reliability and
decreases the costs associated with the operation.
ST-21D5 controller is equipped with a system preventing the pump
from inactivity during extended standstill periods. The pump is turned on
for 1 minute approx. every 10 days.
Additional function is the protection of the system from freezing. After
the temperature measured by the boiler sensor drops below 6°C the
pump is started to operate continuously. The pump is turned off when the
circuit temperature is increased to 7°C.
ALARM
OPERATION
OF THE UNIT
MANUAL
OPERATION
MENU
SELECTION AND
ACCEPTANCE OF
SETTINGS
Main screen: selection
of temp. T2 view
Edition: minus button
Manual operation:
turning the pump off