Instruction of SR81 Split Pressurized Solar Hot Water System
Page 24 of 59
If no password is set, then just press “SET” five times to access main menu directly.
8.2 LOAD tank heating
Function description:
△
T control logic
The controller works as a standard temperature differential controller. If the temperature
reaches or exceeds the switch-on temperature difference (DTO), the pump R1 switches on.
When the temperature difference reaches or falls below the adjusted switch-off temperature
difference (DTF), the respective relay R1 switches off.
Note:
The switch-on temperature difference must be 0.5K higher than the switch-off
temperature difference. The set temperature difference must be at least 0.5K higher
than the switch-on temperature difference.
Pump speed control
If the temperature reaches or exceeds the set point of the switch-on temperature difference,
pump is triggered and runs for 10 seconds at the 100% speed, and then, pump speed is
reduced to its lowest pump speed.
If the temperature reaches the set temperature difference TDS, pump speed is increased
10%
，
controller will adjust by parameter RIS to meet this change. Temperature difference
rises a range which defined by parameter RIS, pump speed increases 10% until to its
maximum pump speed 100%. If temperature difference drops a range which defined by
parameter RIS, pump speed reduces 10% accordingly.
Note:
in order to activate the pump speed control function, control type of the
corresponding of pump should be set (MIN, MAX), there are 4 pump control types, they are
PULS, PSOL, PHEA or 0-10V (adjustable under menu pump)
SMX Maximum tank temperature protection set
If the tank temperature reaches the adjusted maximum temperature, then tank will no longer
be loaded in order to avoid damage caused by overheating. If the maximum tank
temperature is exceeded, sign is displayed on the screen.
The sensor for tank maximum limitation (SMAX) can be selected. The maximum limitation
always refers to the sensor selected (T2 or T3). The switch-on hysteresis (HYST) is
