Lc 221 Controller - Grundfos Multilift M Montage- Und Betriebsanleitung

5.2 LC 221 controller

The LC 221 is a level controller specially designed for controlling
and monitoring the Grundfos lifting station, Multilift M. The basis
for the control is the signal received continuously from the
piezoresistive, analogue level sensor.
The level controller switches the Multilift M pump on and off
according to the liquid level measured by the level sensor.
When the start level is reached, the pump will start, and when the
liquid level has been lowered to the stop level, the pump will be
stopped by the controller. An alarm will be indicated in case of
high liquid level in the tank, pump failure, etc.
The level controller has many more functions, as described
below.
Fig. 6 LC 221 level controller for Multilift M
The LC 221 controller has the following functions:
• on/off control of one wastewater pump based on a continuous
signal from a piezoresistive level sensor
• motor protection via motor-protective circuit breaker and/or
current measurement as well as connection of thermal
switches
• motor protection via operating-time limitation with subsequent
emergency operation. Normal operating time is max.
20 seconds, and the operating time is limited to three minutes
(see section 6.4 Description of fault
F011).
• automatic test runs (2 seconds) during long periods of
inactivity (24 hours after last operation)
• re-starting delay up to 45 seconds after returning from power
cut-off to mains operation (in order to even out the mains load
when several appliances are started up at the same time)
• setting of delay times:
– stopping delay (time from the stop level is reached till the
pump is stopped) - reduces water hammer if pipes are long
– starting delay (time from the start level is reached till the
pump is started)
– alarm delay (time from a fault appears till an alarm is
indicated). This prevents short-time high-level alarm in case
of temporary high inflow to the tank.
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indications, fault code
• automatic current measurement for alarm indications
• setting of current values:
– overcurrent (preset)
– rated current (preset)
– dry-running current (preset)
• operating indication of:
– operating mode (auto, manual)
– operating hours
– impulses (number of starts)
– highest measured motor current.
• alarm indication of:
– pump status (running, fault)
– phase-sequence fault and missing phase
– thermal-switch failure
– high-level alarm (5 seconds delay)
– time for service/maintenance (selectable).
• selection of automatic alarm resetting
• fault log of up to 20 alarms
• selection between different start levels
• selection of maintenance interval (0, 3, 6 or 12 months).
As standard, the LC 221 has four potential-free outputs for:
– pump running
– pump failure
– high-level alarm
– common fault.
Furthermore, LC 221 has six inputs for the following functions:
– connecting an analoque sensor (4-20 mA or 0-5 V)
– connecting up to four level switches or pressure switches
instead of the analogue sensor. An additional float switch
can be connected to the alarm input as backup for the
analogue sensor.
– connecting a separate level switch to be used for flood
detection outside the Multilift M. Lifting stations are often
installed in a sump inside the basement - the lowest point in
the building. In case of e.g. groundwater inflow or water pipe
burst, an alarm will be indicated by the controller.
– connecting a piezoresistive pressure sensor PCB
(pre-assembled)
– connecting an external alarm reset
– connecting the thermal switch of the motor.
For updates and further adjustments, a PC Tool can be
connected. See service instructions.
To allow for the situation that the normal power supply should fail,
a battery (accessory) can be installed which activates an acoustic
alarm (buzzer). The buzzer is activated as long as the fault exists.
It cannot be reset.
In case of sectional power failure, the common alarm output,
which is a potential-free changeover contact, can be used to
forward the alarm signal to a control room by means of an
external power source.