FCL18-02
Multifunction Liquid Level Relay | 6 Selectable Modes | 1 or 2 Electrode Probes
Precision Liquid Level Control in 18mm Width
The FCL18-02 is a high-reliability liquid level relay supporting 1-pole or 2-pole level probes for water level monitoring, tank filling/emptying, and industrial fluid management. With a wide input voltage range (AC/DC 12–240V) and strong anti‑interference capability, it delivers consistent performance even in harsh industrial environments.
Using three front‑panel buttons (Func, Sensitivity, T), you can select from 6 operating modes (A–F), adjust sensitivity (10–100kΩ), and set a time delay (0.1s–20s). The relay output is rated 16A SPDT, suitable for direct load switching.
Quick Specifications
Why Choose the FCL18-02?
Engineered for reliable liquid level monitoring and control in industrial environments.
6 Selectable Modes
Functions A–F: Fill, empty, delayed fill/empty, and overrun timer for 1‑probe or 2‑probe control.
Adjustable Sensitivity
Fine‑tune the response threshold (10–100kΩ) to match different probe lengths and liquid conductivity.
16A SPDT Relay
Directly switch pumps, valves, or alarms. Mechanical life up to 10 million cycles.
Tool‑Free Configuration
Three buttons (Func, Sensitivity, T) for mode, sensitivity, and delay. No software required.
Wide AC/DC Supply
Universal 12–240V AC/DC input – one model works for global installations without modifications.
Operating Modes (A–F)
6 selectable functions for fill, empty, time‑delayed fill/empty, and overrun timer applications.
Mode A – Fill (2 probes)
When water level drops below probe S2, the pump starts and fills the tank until the water reaches probe S1. Standard two‑probe fill control.
Mode B – Delayed Fill (1 probe)
When water level drops below probe S1, the pump starts after the set delay T and fills until the water reaches S1 again. Delayed start prevents rapid cycling.
Mode C – Fill with overrun (1 probe)
When water level drops below probe S1, the pump starts immediately and fills until water reaches S1, then continues running for an additional time T. Ensures complete filling beyond the probe point.
Mode D – Delayed Empty (1 probe)
When water level rises above probe S1, the pump starts after the set delay T and empties until the water drops below S1. Delayed start for emptying applications.
Mode E – Empty with overrun (1 probe)
When water level rises above probe S1, the pump starts immediately and empties until water drops below S1, then continues running for an additional time T. Ensures complete draining.
Mode F – Empty (2 probes)
When water level rises above probe S1, the pump starts and empties until the water drops below probe S2. Standard two‑probe emptying control.
Technical Specifications
| Parameter | Specification |
|---|---|
| Supply Voltage | AC/DC 12‑240V (-15% / +10%) |
| Power Consumption | AC 3.5VA / DC 2.0W |
| Supply Indication | Green LED (Un) |
| Relay Indication | Red LED (R) |
| Number of Functions | 6 (A–F, selectable via Func button) |
| Sensitivity Setting | 10kΩ – 100kΩ (adjustable) |
| Time Delay (T) | 0.1s – 20s (adjustable) |
| Output Contact | 1 × SPDT (NO+NC) |
| Rated Current | 16A / 250V AC |
| Mechanical Life | 1 × 10⁷ operations |
| Electrical Life | 1 × 10⁵ operations |
| Ambient Temperature | -20°C … +60°C |
| Storage Temperature | -40°C … +85°C |
| Mounting | DIN rail EN/IEC 60715 (35mm) |
| Dimensions (H×W×D) | 90 × 18 × 64 mm |
| Weight | 68g |
| IP Rating | IP20 |
| Standards | GB/T 14048.5, IEC 60947‑5‑1, EN 61812‑1 |
Terminal Connections
FCL18-02 – Single‑phase AC/DC liquid level relay
- De‑energize the panel before wiring.
- Verify supply voltage matches AC/DC 12‑240V rating.
- Connect the load (pump/valve) between terminal 11 and 14 (NO) for normal operation.
- Use correct wire gauge for 16A load (min 1.5mm²).
- Tighten screws to 0.4 N·m; stripping length 7mm (AWG13‑20).
Front Panel & Settings
Configure mode, sensitivity, and time delay using three buttons – no software needed.
Un – Green LED
Lit = power supply applied
R – Red LED
Lit = relay output active (NO closed)
How to Set Parameters
- Enter setting mode: Press and hold the Func button until the green LED starts flashing.
- Select function: Press Func repeatedly to cycle through modes A–F. The red LED blinks to indicate the mode number.
- Adjust sensitivity: Press Sensitivity button to set the probe resistance threshold (10kΩ–100kΩ).
- Adjust time delay: Press T button to set delay time (0.1s–20s).
- Confirm & exit: Press and hold Func again until the green LED stops flashing. Settings are saved.
Note: In modes B, C, D, E the time delay T is used as a start delay (B/D) or overrun timer (C/E). In modes A and F, T is not used.
Model Comparison
| Model | Function | Probe Poles | Modes | Sensitivity | Delay |
|---|---|---|---|---|---|
| FCL18-02 | Multifunction level relay | 1 or 2 poles | 6 (A‑F) | Adjustable 10‑100kΩ | 0.1‑20s |
| FCL18-01 | Single‑function level relay | 2 poles only | 1 fixed mode (Fill/Empty) | Fixed (approx. 50kΩ) | Fixed or minimal adjust |
Product Video
Typical Applications
Water Tanks
Automatic fill/empty control for residential or industrial reservoirs.
Wastewater
Pump station level monitoring and alarm triggering.
Cooling Towers
Maintain proper water level in industrial cooling systems.
Food & Beverage
Sanitary level control for mixing tanks and dosing systems.
Ready to Order or Need More Details?
Download the datasheet or contact FIICCO for pricing, samples, and OEM options.
Frequently Asked Questions
FCL18-02 is a multifunction relay with 6 selectable modes (A–F), adjustable sensitivity (10–100kΩ), and adjustable time delay. FCL18-01 is a single‑function relay for basic 2‑probe fill or empty applications with fixed sensitivity and delay.
Connect the common reference electrode to terminal C. Connect the high‑level probe to S1 and low‑level probe to S2. For 1‑probe modes, only S1 and C are used. The exact function of each terminal depends on the selected mode (A–F).
The FCL18-02 accepts AC/DC 12–240V (‑15% / +10%). One model works for 12V, 24V, 110V, 230V AC or DC systems.
Press and hold the Func button until the green LED flashes. Then press Func repeatedly to cycle through modes A–F. The red LED indicates the mode number. Press and hold Func again to save.
The SPDT output relay is rated 16A at 250V AC (resistive load), suitable for direct control of pumps, contactors, and valves.
Yes. We provide custom branding, model numbering, packaging, and even tailored specifications for volume orders. Contact us for details.