Solar Temperature controller for Two-loop System

Posted by: admin-smartclima | October 13, 2013

Solar Temperature controller for Two-loop System

BF-440A is a temperature controller with two inputs and two outputs. It includes two NTC temperature sensors. The 1^st loop is relay output, normally open or closed; and 2^nd loop is relay output, normally open.

The ranges of controlled temperature of two loops are programmable (range of controlled temperature includes two values which are the maximum temperature and range of fluctuation). When water temperature > the max. Temperature which has been set, the normally open point in 1^st loop off, and the normally closed point is on; and that the normally open contact in 2^nd loop is off (there is no normally closed contact in 2^nd loop.)

Measurement error correction function is designed to rectify temperature measurement error, which may result in misoperation to appliance, due to long-distance output.

EEPROM, when the controller shuts down, all the parameters that have been set are saved and readable after controller shuts off, to avoid re-setting each time when the controller is connected to appliance.
How does it work
While it is working, the controller display the temperature of water, which is “T”, “Tc1” means value of temperature control of 1st loop, and “Tr1” means value of temperature floating downward of 1st loop;
“Tc2” means value of temperature control of 2nd loop, and “Tr2” means value of temperature floating downward of 2nd loop.
Temperature control of 1st loop:
T>=Tc1, normally open contact is off(stopping heating), and normally closed contact is on;
T<=(Tc1-Tr1), normally open contact is on(beginning to heating), and normally losed contact is off.

Temperature control of 2nd loop:
T>=Tc2, normally open contact is off, and normally closed contact is on;
T<=(Tc2-Tr2), normally open contact is on, and normally closed contact is off.

Power supply
220VAC/50Hz; power consumption: <4W

Display
4 digits LED display, (HV/ LV)

Sensor
NTC temperature sensor, sensor cable is extendable with two-core wire within 200m, two temperature sensors included.

range of temperature	-20°c~+140°c; accuracy: ≤±1°c
range of control	-20°c~+120°c
range of temperature fluctuation	0°c~30°c
range of measurement error correction	-10°c~+10°c
Accuracy of setting	1°c

Relay output
1st loop is normally open or closed, and 2nd loop is normally open, resistance, AC220V, 6A
EEPROM
Electrically erasable programmable read only memory, all the parameters that have been set are saved and readable even the controller shut off.

Wiring diagram: