
07/2015
Temperature Difference Controller TDC 3
Page 41 of 47
7.9 Speed control
If the speed control is activated, the TDC3 makes it possible to vary the speed of standard pumps
at relay R1 by means of special internal electronics.
7.9.1 Variant
The following speed variants are available here:
Off: There is no speed control. The connected pump is only switched on or off with full speed.
Variant V1: After the purging time the controller switches to the set max. speed. If the temperature
difference
∆
T between the reference sensors (collector and storage tank) is less than the set
value, then the speed is decreased by one stage after the control time elapses. If the temperature
difference between the reference sensors is greater than the set value, then the speed is
increased by one stage after the control time elapses. If the controller has adjusted the speed of
the pump down to the smallest stage and the
∆
T between the reference sensors is
∆
T off, the
pump is switched off.
Variant V2: After the purging time the controller switches to the set min. speed. If the temperature
difference
∆
T between the reference sensors (collector and storage tank) is greater than the set
value, then the speed is increased by one stage after the control time elapses. If the temperature
difference
∆
T between the reference sensors is below the set value, then the speed is decreased
by one stage after the control time elapses. If the controller has adjusted the speed of the pump
down to the smallest stage and the
∆
T between the reference sensors is T
∆
off, the pump is
switched off.
Variant V3: After the purging time the controller switches to the set min. speed. If the temperature
at the reference sensor (collector) is greater than the setpoint to be set subsequently, then the
speed is increased by one stage after the control time expires. If the temperature at the reference
sensor (collector) is less than the setpoint to be set subsequently, then the speed is decreased by
one stage after the control time expires.
Setting range: V1,V2,V3, off/default setting: Off
Variant V4: (2 storages)
When the valve is set toward the primary storage, speed control works as in V3.
When the valve is set toward the secondary storage, speed control works as in V2.
Settings range: V1,V2,V3, Off / Default: Off
Caution
This function should only be activated by a specialist. Depending on the pump and
pump stage used, the minimum speed should not be set too low, because otherwise
the pump or the system may be damaged. The information provided by the relevant
manufacturer must also be observed! If in doubt, the min. speed and the pump stage
should generally be set to high rather than too low.