Operation manual of solar controller SR658
Page 31 of 105
T3
Optional sensor, undefined
R4
1.TIMER (Timer heating)
2.OPARR
（
Parallel relay
）
3. Thermostat function
T4
Temperature of heat exchanger
(optional)
R5
1. OHDP
（
Thermal transfer
）
T5
Temperature of thermostat (optional)
T6
Optional sensor, undefined
T7
Temperature for thermal energy
measurement (optional)
HR
Back-up heating
System 16: Solar system with 1 collector field, 1 tank, valve and heat exchanger
control
Description:
The controller calculates the temperature difference between collector sensor T1 and tank or
heat exchanger sensor (T2, T5). If the difference is larger than or identical to the adjusted
switch-on temperature difference, then solar circulation pump (R1) will be switched on. And
according to priority logic, valve R4 turns to the tank or heat exchanger, tank and heat
exchanger is heated one by one. When temperature difference between collector sensor T1
and tank or heat exchanger sensor
（
T2,T5
）
drops to the switch-off temperature difference or
the maximum temperature of tank (T2) or swimming pool (T5) is reached, then solar pump
R1 is ceased.
The priority logic effects prior loading of the tank.
Please refer the Paragraph of "LLOGI Tank priority logic"
By using another temperature difference between T5 and T4, R2 can be trigged to heat
swimming pool.
Note:
when T5 is not installed, then temperature difference between collector T1 and
swimming pool T4 is larger than or identical to the adjusted switch-on temperature difference,
then solar circulation pump (R1 and R2) and valve R4 all will be switched on simultaneously.
And when temperature difference between collector sensor T1 and swimming pool T4 drops
to the switch-off temperature difference or the maximum swimming pool (T4) temperature is
reached, then solar pump R1, R2 and valve R4 are ceased simultaneously.
