Installing the level control device
DANGER
Explosion hazard through incorrect installation of level control!
If the level control is installed in a potentially explosive atmosphere, there is a risk of explosion if the signal transmitters are incorrectly connected.
- Connect all signal transmitters with an Ex cut-off relay or a Zener barrier.
- A qualified electrician must do the electrical work.
CAUTION
System malfunction through incorrect installation of the level controller.
To prevent the pumping station from malfunctioning, follow these points:
- To prevent backflow into the inlet, set the maximum level below the inlet.
- Do not install the signal transmitters directly in the inlet.
- Make sure the pump's current operating mode matches its designed mode. Obey the start and stop times for S2 or S3 operation mode.
The water level can be measured with these devices:
- Dynamic pressure bell
- Level sensor
- Float switch
Dynamic pressure bell
A dynamic pressure bell measures water levels by checking the static pressure in the pump chamber. Make sure that the dynamic pressure bell emerges after each pumping procedure to get ventilated. Alternatively, a bubbling-through system can be used where a small compressor continuously pumps air into the dynamic pressure bell.
In addition, it is recommended to install a second dynamic pressure bell for autarkic measuring and signalling of the high water alarm.
Level sensor
A level sensor measures water levels using a diaphragm. Make sure that the diaphragm (the lower section of the level sensor) stays constantly immersed. The level sensor cannot be put on the base of the pump chamber.
Float switch
Float switches measure water levels using floats. Make sure that the float switches have sufficient space to move and do not hit into the pump chamber.
1 | Cross beam |
2 | Holder for dynamic pressure bell and level sensor |
3 | Dynamic pressure bell |
- Fit the dynamic pressure bell and the level sensor directly into the holder on the cross beam from above, using the accessories supplied.
- Attach the float switch to the vertical discharge pipe using cable ties. For fault-free level measurement, a free cable length of about 250 mm is required.
- To prevent deposits effectively, make sure to replace the fluid regularly. It is recommended to use the switching points for the lower inlet. The dedicated switching points are shown in the following tables.
Dimension | Description | Rexa MINI3-S03 | Rexa FIT-S03 | Rexa PRO-S03 | Rexa MINI3-V04 |
|---|---|---|---|---|---|
A | Pump off | 660 | 650 | 660 | 710 |
B | Lower edge of dynamic pressure bell 1 | 610 | 600 | 610 | 660 |
C* | "Pump off" signal | 540 | 530 | 540 | 590 |
D | Pump on | 400 | 400 | 400 | 400 |
E | High water: Alarm signal and “Pump on” | 330 | 330 | 330 | 330 |
F | Lower edge of dynamic pressure bell 2 (high water alarm) | 550 | 550 | 550 | 550 |
G | Level fall during follow-up time | 120 | 120 | 120 | 120 |
* Switching point C: Set “Pump off” signal when using dynamic pressure bell and level sensor; then set follow-up time up to “dimension A” (pump off); set follow-up time if there is no inlet.
If a higher gross volume is required due to a higher inflow, these switching points can also be used for the upper inlet.
Description | Switching point |
|---|---|
“Pump on” at upper inlet | 110 |
High water at upper inlet | 60 |
Alarm signal for high water level
To prevent operation failure of the pump chamber, it is recommended to use a high water alarm. Make sure that the switchgear have the necessary function.
