NewTrend · Liquid level control relay
Product overview
NewTrend RL8-02 controls filling or draining from electrode-based level signals in wells, tanks, basins and reservoirs. The front selector provides pump-up or pump-down operation with one- or two-level control. Adjust sensitivity from 5 to 100 kilohms and output delay from 0.1 to 10 seconds. The 18mm DIN-rail relay has an AC/DC 24-240V supply and one SPDT output rated 10A AC-1.
Technical selection summary
| Model | RL 8-02 |
|---|---|
| Function | One- or two-level electrode control; pump up or pump down |
| Control supply | AC/DC 24-240V, 50-60Hz |
| Supply terminals | A 1-A 2 |
| Power input | Maximum 2VA |
| Supply tolerance | -15% to+10% |
| Electrode terminals | Max, Min and C; connect according to selected mode |
| Sensitivity (input resistance) | Adjustable 5-100kΩ |
| Electrode voltage | Maximum AC 5V |
| Probe current | AC below 0.1mA |
| Response time | Maximum 400ms |
| Output delay (RL8-02) | Adjustable 0.1-10 seconds |
| Mechanical setting accuracy | ±10% |
| Maximum probe-cable length | 800m at 25kΩ sensitivity; 200m at 100kΩ |
| Maximum probe-cable capacitance | 400nF at 25kΩ sensitivity; 100nF at 100kΩ |
| Output contacts | 1 SPDT; 11-12-14 |
| Contact rating | 10A, AC-1 |
| Switching voltage | 250VAC /24VDC |
| Minimum DC breaking power | 500mW |
| Output indication | Red LED |
| Mechanical life | 10, 000, 000 operations |
| Electrical life (AC-1) | 100, 000 operations |
| Reset time | Maximum 200ms |
| Temperature coefficient | 0.05%/degree C at 20 degrees C |
| Operating temperature | -20 to+55 degrees C |
| Storage temperature | -35 to+75 degrees C |
| Mounting | DIN rail to EN/IEC 60715; 18mm module |
| Protection | IP 40 front panel;IP 20 terminals |
| Operating position | Any |
| Overvoltage category /pollution degree | III /2 |
| Maximum conductor size | Solid: 1 x 2.5mm² or 2 x 1.5mm²;with sleeve: 1 x 2.5mm² (AWG 12) |
| Terminal tightening torque | 0.8Nm |
| Body dimensions | 90 x 18 x 64mm |
| Weight | 72g (dedicated RL 8-02 manual and official product page) |
| Referenced standard | EN 60255-1 |
Operation
- Choose pump-up or pump-down using the front function selector. The factory diagrams show separate two-level and one-level timing modes.
- Use Max, Min and C electrode terminals as shown for the chosen level-control mode; A1-A2 supplies the relay and 11-12-14 forms the output changeover contact.
- The sensitivity potentiometer sets the electrode-circuit resistance threshold. The Tt potentiometer sets the RL8-02 output delay from 0.1 to 10 seconds.
Typical applications
- Tank filling and draining through suitable external pump contactors
- Level control in wells, basins and reservoirs
- Electrode-based water-level supervision in control panels
View or download RL8-01/02 liquid-level control catalogue (PDF)
Product reference images and drawings
Original specifications, electrode terminals and level wiring
Original filling/draining timing modes and dimensions
Set the required pump direction, level-control mode, sensitivity and delay using the original function diagrams. Keep the probe-cable length and capacitance within the limits for the selected sensitivity. Use a suitably rated external contactor for the pump load. Installation and wiring must be performed by qualified electricians.
