The Dual Level Controller allows control of the liquid level in a tank between two points and/or an extra control output in the event that the tank over or under fills. The Dual Level Controller (DLC) provides safe low voltage for the level switches which may become submersed and has high power relay contacts to control a pump or a solenoid valve in a gravity fed top-up system.

The DLC-1 provides one relay that can be configured to provide dual level control or just buffer a single float switch or other light duty switching device. The DLC-2 has an additional totally independent relay that can be used for any purpose. For example, a pump can run dry and become damaged if there is a lack of liquid in the tank in a pumped output system. A float switch can be set just above the level where this occurs and the relay contacts of the DLC-2 wired to cut the electrical supply to the pump motor. The DLC-3 offers an IP65 rating in addition to the features of the DLC-2.

The uses of this product are diverse – please call us to discuss potential applications.

Please note that the DLC-2 is shown in the picture with float switches; these are sold separately. To view our range of float switches, please click here.

Wiring Example


In Figure 1 a valve is opened to fill the tank. The top float-switch goes to the terminals labelled ‘A’ and the bottom switch to the terminals labelled ‘B’. Note that the switches are open-circuit when the float rises (open when full).
In Figure 2 a valve is used to empty the tank. The top float-switch goes to the terminals labelled ‘B’ and the bottom switch to the terminals labelled ‘A’ and they open-circuit when the float falls (open when empty).

We manufacture many standard float switches that are compatible with the DLC-1, DLC-2 & DLC-3 and we also manufacture custom designed float switches to suit your specific requirements. Please call us to discuss potential applications.



Dimensions 63mm x 180mm x 175mm (including cable glands)
IP Rating Standard DLC – IP41
Sealed option – IP65
Temperature Range -20°C to +80°C
Power Requirement 10-14VDC @ 100mA
Mains Power Adapter – Supplied 100-240VAC input, 12VDC output @ 500mA
Power Input Terminal Standard DLC – 2.1mm socket, centre positive
Sealed option – screw terminals
Power Input Fuse 500mA anti-surge, 5x20mm cartridge
Float-switch Inputs – ‘Open’ State >10k ohms, DC supply voltage across switch (typ. 12V)
Float-switch Inputs – ‘Closed’ State <100 ohms, 1.2mA (typ.) through switch
Relay Contacts – Maximum Current 8A continuous, 15A peak
Relay Contacts – Maximum Voltage 250VAC
Wire Sizes – Relay Screw Terminals 20 AWG – 12 AWG (2×14 AWG for ‘earth’ feed-through)
0.5mm2 – 3.3mm2
Wire Sizes – Float-switch Terminals 24 AWG – 14 AWG
0.2mm2 – 2.0mm2
Cable Sizes – High Voltage Side 4.5mm – 10mm diameter
Cable Sizes – Low Voltage Side 3.5mm – 7mm diameter

Download the DLC Series Datasheet

Download the DLC Series User Guide

Dual Level Controllers

  • DLC-1

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  • DLC-2

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  • DLC-3

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