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NRS 1-56 - Installation & Operating Manual -
850142-00
Function
The NRS 1-56 level switch measures using the conductivity principle and makes use of the electrical
conductivity of the water to do this.
The level switch is designed for different conductivities and for connection to four electrode rods in total.
The level switch functions as an interval level control system (inlet/discharge/switchable), and also indi-
cates when the water reaches two independent alarm states, which can be configured as MIN or MAX.
The switchpoints for water level control and for the MIN or MAX levels are determined by the length of the
respective electrode rods.
For water level control, the level switch recognises whether the electrode rods are immersed or out of the
water and, depending on which function is set, it switches the controller output contact, which then turns
the feedwater pump on or off, for example. The Pump LED lights up when the level switch has switched
the feedwater pump on, for example.
Behaviour in the event of MIN/MAX water level alarms
When the MIN or MAX water level is reached, the level switch recognises that the corresponding electrode
rod is immersed or no longer immersed. When the off delay has elapsed, the relevant Alarm 1/2 output
contact is switched. The alarm 1/2 LED simultaneously lights up red.
Alarm simulation
A button is pressed to begin a test sequence. During the test sequence, the MIN or MAX alarm is
simulated, see table on page 26.
Behaviour in the event of error messages
If faults occur in the level electrode and/or the electrical connection, the integrated relays are
de-energised.
Alarm and fault indications are displayed by LEDs, see page 28.
