Operation manual of solar controller SR658
Page 24 of 105
System 9: Solar system with east/west collector fields, 2 tanks, valve logic control
Description:
The controller calculates the temperature difference between east/ west collector sensor T1
and T0 and 2 tanks base sensor T2 and T4. If any difference is larger than or identical to the
adjusted switch-on temperature difference, then solar circulation pump (R1 or R2) will be
switched on, and simultaneously valve R4 turns to the corresponding tank, and this tank
will be loaded until the switch-off temperature difference or the maximum tank temperature is
reached.
The priority logic effects prior loading of the tank 1.
Please refer the Paragraph of "LLOGI Tank priority logic"
Sensor Description
Relay Description
T0
Temperature of collector 2
R1
Solar circulation pump 1
T1
Temperature of collector 1
R2
Solar circulation pump 2
T2
Temperature of tank 1 base
R3
1. SFB
（
Solid fuel boiler
）
T3
Temperature of tank 1 upper
(optional)
R4
Valve of solar circuit
T4
Temperature of tank 2 base
R5
1. TIMER
（
Timer function
）
2. OPARR
（
Parallel relay
）
3. Thermostat function
4. OHDP
（
Thermal transfer
）
5. CIRC
（
DHW circulation
）
T5
1.Temperature of tank 2 upper
(optional)
2.Temperature of solid fuel boiler
T6
Sensor for DHW temperature or
for flow switcher (optional)
T7
Temperature for thermal energy
measurement (optional)
HR
Back-up heating
