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NRR 2-52, NRR 2-53, URB 55 - Installation & Operating Manual -
850646-00
Function
In the level controller, the actual value is compared with the set point, and a corrective signal is formed
to compensate the control deviation. In addition, switching operations can be triggered by the output
contacts if defined switchpoints are reached.
Possible combinations of functions and equipment
Combining the NRR 2-52, NRR 2-53 level controller with the level electrodes and the URB 55 visual display
and operating unit provides the following common functions:
Level controller
NRR 2-52
NRR 2-53
Evaluating voltage signals from the connected NRG 2x-xx level electrodes
with standardisation of the measuring range
l
l
Evaluating the current signal of a connected NRGT 26-x level transmitter
l
l
3-position stepping controller with proportional plus integral control (PI controller)
and actuation of an electrically operated control valve
l
Continuous controller as a PI controller for actuating an electro-pneumatic
control valve
l
Continuous controller as a PI controller for actuating for actuating frequency-controlled
pumps
l
MIN/MAX water level alarm
l
l
Current inputs for steam and feedwater flowrate
(3-component control) (optional)
l
l
The valve position is indicated by connecting a potentiometer (in the control valve)
l
Actual value output 4-20 mA
l
l
2 x pump enable (ON/OFF) with actuation of a frequency-controlled pump *
l
* Controller software version 311178.13 or later
Fig. 3
