GESTRA NRR 2-50, Оригинальное руководство по установке и эксплуатации

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11 NRR 2-50, NRR 2-51 - USA - Installation & Operating Manual -
850699-00
Function
The NRR 2-50, NRR 2-51 level controller processes the level-dependent current signal from the
NRGT 26-2 level transmitter. In the controller, this input signal is standardized to 0 and 100% of
the boiler measuring range and shown as an actual value on the 7-segment LED display.
Level controller NRR 2-50:
The level controller works with an electrically actuated control valve
as a 3-position stepping controller with proportional-plus-integral control action
(PI controller)
.
If the actual value deviates from the set point, the electric actuator is triggered by two output
contacts and two flashing LEDs indicate whether the control valve is opening or closing.
The controller can be configured for fill or drain control.
A further output contact indicates when a MIN or MAX water level is reached (the desired function
is switch-selectable). After the off delay has elapsed, the output contact switches and the MIN or
MAX LED lights up.
Level controller NRR 2-51: The level controller works with an electro-pneumatically actuated
control valve as a continuous controller with proportional-plus-integral control action
(PI controller) . In the event of deviations from the set point, it outputs a current of 4-20 mA as
manipulated variable Y.
The controller can be configured for fill or drain control.
If the MIN or MAX water level is reached, after the off delay the MIN or MAX output contact
switches in the level controller, and the MIN or MAX LED lights up.
Level controller NRR 2-50, NRR 2-51: Faults in the level transmitter or the electrical connection
and setting errors are indicated as error codes on the 7-segment LED display. In the event of a
malfunction, the MIN and MAX alarm is triggered.
If faults occur only in the
NRR 2-50, NRR 2-51 level controller
, the MIN and MAX alarm is
triggered and the system is restarted.
Parameters can be changed or the MIN/MAX alarm simulated by turning the rotary knob.
To enable an external level display, the
NRR 2-50 level controller is optionally available with a
4 - 20 mA actual value output.