Modular Liquid Level Control Relay | 5A | 150-260VAC | <100kΩ | DIN

The relay determines the liquid level based on electrical conductivity between the electrodes and the liquid. Upper (U), lower (L), and common / bottom (B) electrodes are used. When the liquid reaches the upper electrode, the relay is activated, and when the level drops below the lower electrode, it is switched off. Sensitivity can be adjusted up to 100kΩ, allowing the relay to be adapted to liquids with different conductivity levels.

The device has an adjustable sensitivity setting of up to 100kΩ. When adjusting sensitivity, all electrodes in use must be in contact with the liquid. Gradually turn the sensitivity control toward 100kΩ. When the device reliably detects the electrodes through the monitored liquid, the relay operates. The electrical resistance of the liquid must be lower than the configured sensitivity value.

If a two-electrode system is used, the upper (U) and lower (L) level inputs must be connected together and used in combination with the common / bottom electrode (B).

• Automatic liquid level control in reservoirs, tanks, or wells.
• Can be used in both filling and liquid pumping control systems depending on the wiring configuration.
• Adjustable sensitivity up to 100kΩ allows the relay to be adapted to liquids with different electrical conductivity.
• The three-electrode system allows upper and lower liquid level points to be defined.
• The 15-16-18 changeover relay contact provides flexible integration into automation circuits.
• Compact housing suitable for installation in control panels and on DIN rails.

• For conductive liquids only: the operating principle is based on the electrical conductivity of the liquid, therefore the relay is not suitable for electrically non-conductive liquids.
• IP20 protection class: the controller itself must be installed in a suitable control panel and protected against direct exposure to water and moisture.
• Relay contact load: the output is rated for up to 5A / 250V AC resistive load. A contactor is recommended for controlling higher loads.
• Not intended for flammable or explosive liquids: the manufacturer specifies that the device must not be used to monitor flammable or explosive liquids.

Three electrodes are installed in a water tank: the common electrode B at the bottom of the tank, the lower-level electrode L at the minimum permissible water level, and the upper electrode U at the maximum level. As the water rises and reaches electrode U, the relay is activated and can switch off the water supply pump through the control circuit. As the water level decreases, the relay remains active until the water drops below electrode L. The relay then switches off and the pump control circuit can be activated again.

The device operates within a supply voltage range of 150V – 260V AC at a frequency of 50/60Hz.

The relay is designed for electrically conductive liquids such as water. The electrical resistance of the liquid must be lower than the configured sensitivity value of the relay.

Yes. The device has adjustable sensitivity up to 100kΩ, allowing it to be matched to the electrical conductivity of the monitored liquid.

The standard system uses an upper U, lower L, and common B electrode. The manufacturer also provides for a two-electrode system in which the U and L inputs are connected together.

The relay output contact is rated for up to 5A / 250V AC resistive load. For higher-power pumps, it is recommended to use the relay as a control signal for a contactor or another power control device.

No. The manufacturer clearly specifies that the monitored liquid must not be flammable or explosive.

Use the device according to the manufacturer's instructions. Do not use the device in a humid environment and do not allow the controller itself to come into contact with water. Provide a separate switch and automatic circuit breaker in the installation circuit. They must be installed near the device, in an easily accessible location, and marked as the means for disconnecting the device. The monitored liquid must not be flammable or explosive.

Before performing maintenance, switch off the device power supply and disconnect it from the electrical circuit. Clean the housing with a soft cloth. Do not use conductive materials or chemical cleaners that could damage the device. After cleaning, check that the device operates correctly.