Operation manual of solar controller SR658
Page 22 of 105
System 7: Solar system with east/west collector fields, 1 tank
Description:
The controller calculates the temperature difference between east/ west collector sensor T1
and T0 and tank base sensor T2. 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 tank will be loaded until the switch-off temperature difference or the maximum tank
temperature is reached.
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 base
R3
1. SFB
（
Solid fuel boiler
）
T3
Temperature of tank upper
(optional)
R4
1. CIRC
（
DHW circulation
）
T4
Sensor for DHW temperature or
for flow switcher (optional)
R5
1. TIMER
（
Timer function
）
2. OPARR
（
Parallel relay
）
3. Thermostat function
4. OHDP
（
Thermal transfer
）
T5
Temperature of solid fuel
boiler(optional)
T6
Optional free sensor,
undefined(optional)
T7
Temperature for thermal energy
measurement (optional)
HR
Back-up heating
