V4LM – Fill level measurement with 10 functions
Auf einen Blick
The new V4LM electrode relay from TELE for level monitoring in conductive fluids combines 10 different functions in one very compact device. It monitors the level of a fluid via probes, which are directly immersed. Depending on the function selected, the V4LM controls the pumping in and pumping out as well as the running dry and overflow alarm. The device is utilized wherever observing a defined fill level represents an important criterion for the function, efficiency and safety. It protects machines and systems from leakage damage, fluid loss as well as running dry or overflow.
Unlike float switches, the TELE V4LM has no moving parts and thus has a high service life. In contrast to ultrasonic and radar measurements, the device is resistant to contamination, dust, foam and mist in the containers. With extremely low probe voltage, small measuring currents and a large sensitivity window from 0.25 to 500 kOhm, the fill level measurement is suitable for feed applications and does not endanger the animals. The selected measuring frequency of 18.3 Hz enables an extremely robust measurement without interference (no harmonics to mains frequency 50 or 60 Hz). In addition, the alternating current measurement prevents the build-up of oxyhydrogen gas as well as electrolytic disintegration of the probes, which can occur with comparable devices with direct current measurement.
- Unlike float switches, no moving parts and thus has a high service life.
- In contrast to ultrasonic and radar measurements, resistant to contamination, dust, foam and mist in the containers.
- Robust measurement without interferences.
- Prevents the build-up of oxyhydrogen gas as well as electrolytic disintegration of the probes.
- Leakage damage, fluid loss as well as running dry or overflow of pumps or machines.
- Well control.
- Disposal, waste water and swimming pool technology.
- Chemical industry.
The functions in detail [1-10]
 Pumping in or  pumping out with min/max alarm
1 container, 4 probes, 1 pump
The fill level is kept between the levels of probes E2 and E3 by pumping in and pumping out. Probes E1 and E4 are used for the overflow as well as the dry alarm. Both of these functions are used when fluid is taken from the container by the user process while preventing the container from running dry, or when the container is filled by the user process while keeping it from overflowing.
Pumping in and pumping out (bidirectional) with  min or  max alarm – The fill level is kept between the levels of probes E1 and E3, or E2 and E4 by pumping in and pumping out. The min alarm function  is used when dry running is desired as an alarm criterion (probe E4) and when filling as well as removal takes place through the user process. The max alarm function  is used when overflow is desired as an alarm criterion (probe E1) and when filling as well as removal takes place through the user process.
 Pumping in or  pumping out for two independent containers
2 containers, 1-4 probes, 1-2 pumps
Pumping in or pumping out between probes E1-E2 or E3-E4. (alternatively also control around just one probe). This function enables level control in two separate containers with just one device. It is also possible to control cascades. No alarms.
Pump switch function,  pumping in or  pumping out
1 container, 2 probes, 2 pumps
Pumping in between control probes E1 and E2. The V4LM functions as an intelligent pump switch (for similar use) with pump monitoring. In the event of a pump fault, the remaining pump is permanently prioritized and an alarm is output. This pumping in or pumping out function is used when the system has two redundant pumps.
 Well control
1 well, 1 elevated tank, 3 probes, 1 pump
This function serves to supply water via an elevated tank and well (pumping in water from well into the elevated tank). Alarm functions: well alarm (well dry) and dry alarm (elevated tank as well as well without water).
 Gray code output for connection to PLC
1-4 containers, 1-4 probes, PLC control
The probe states are output via the three output relays using gray coding. So for one container up to four fill levels can be evaluated, for instance via PLC control.
If only one probe is installed per container, up to four containers can be monitored for overflow / running dry (without assigning which container sends the alarm).