IM-P693-01
EMM Issue 2
3
LCR2250 Level Controller
2.1 Intended use
The LCR2250 level controller is used in combination with a LP20/LP21/PA420 level transmitter as a limit
switch and water level controller, e.g. in steam and water boiler systems, or in condensate and feedwater
tanks. The level controller indicates when a MIN or MAX water level has been reached, and opens or closes
a control valve.
2.2 Function
The LCR2250 level controller processes the level-dependent current signal from the LP20/LP21/PA420 level
transmitter. This input signal is recognised by the controller as 0 and 100 % of the boiler measuring range,
and shown as an actual value on the 7-segment LED display.
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 setpoint,
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 discharge control.
A further output contact indicates when a MIN or MAX water level is reached (the desired function can be
selected by a switch). After the de-energizing time has elapsed, the output contact switches over and the
MIN or MAX LED lights up.
Faults in the level transmitter, the electrical connection or the settings 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 LCR2250 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 operating the push buttons. For external
level indication, the LCR2250 level controller has a 4 - 20 mA actual value output.
2. General product information
Fig. 1
