# Water level control relay module, 9-12V, automatic

> Water level control relay module (ref. 9938), operates automatically at 9-12V AC or DC. Uses 3 electrodes (GND, minimum level, maximum level) to detect liquid level and drive a relay with open-close contact output, rated up to 10A, controlling power of 0-1KW at 220V. Features screw terminals for quick wiring without soldering. Board dimensions: 60 x 50 x 25 mm.

- Page: https://sigmanortec.ro/en/water-level-control-relay-module-9-12v-automatic
- Price: 38.90 RON
- Availability: In stock; 1-2 zile
- Reference: 9938 · EAN: 5948664340863
- Category: Mechatronics and IoT > Sensors and Modules > Level and Liquid Sensors
- Specifications: Supply Voltage: 9; Maximum Input Voltage: 12; Output Type Voltage: Closed-Open Contact; Input Voltage Type: “DC” in Romanian can mean **“de ce”**, which translates to **“why”** in English.
- Package (shipping data): 0.035 kg
- Updated: 2026-09-14
- Shop: [Sigmanortec.ro](https://sigmanortec.ro/en/llms.txt)
- Prices: RON, VAT included; prices and stock as of 2026-10-22 04:49 (Europe/Bucharest)

## Description

Automatic level controller with relay for starting and stopping the pump depending on the water level in the tank, uses 3 simple electrodes for minimum and maximum detection, operates at 9-12V AC or DC, offers relay output up to 10A for controlling loads, has screw connectors for quick wiring without soldering.
Automatic water level controller with relay, designed to monitor and control the operation of water pumps, by detecting the level in a tank or water tower and activating a relay to automatically start or stop the pump.
The module operates with both DC and AC voltage between 9 and 12V and features screw connectors for quick wire connection without the need for soldering.
The controller uses three wires inserted into the water to detect the liquid level:
GND wire (common) – placed at the bottom of the tank.
Minimum level wire – determines when the pump should be turned on.
Maximum level wire – determines when the pump should be stopped.
The wires inserted into the water will have the insulation removed for a minimum length of 3cm and it is recommended to use stainless steel wires because current is passed through the wires to measure the conductivity between the lower and upper levels to GND.
For a longer lifespan, it is recommended to use stainless steel wires, as they are more resistant to corrosion.
Specifications:
Power supply: 9V-12V (AC or DC) (It is not recommended to use a switching power supply for safety)
Control output: Current 0~10A
Controlled power: 0~1KW at 220V (theoretically can control up to 2KW, recommended below 1KW)
Plate dimensions: 60 × 50 × 25 mm
Use:
Installation of detection wires:
Insert the GND wire into the bottom of the tank.
Place the minimum level wire at the height at which you want the pump to start.
Place the maximum level wire at the height at which the pump should stop.
Strip the wire ends for a length of approximately 3 cm for correct detection.
Use a 9V-12V power supply (AC or DC), avoiding switching power supplies.
Check that the pump power does not exceed 1KW for safe operation.
Fill and partially empty the tank to check if the pump starts and stops according to the water level.