Cobra EL-JOE electronic sensor hands free tap

The Cobra EL-JOE is an electronic sensor tap used for hands free washing. It is an industrial designed tap suitable for continuous washing  in places like factories, food processing plants, hospitals, clinics, schools, shopping malls, sports arenas atc. It is designed to provide cold water or pre-mixed water. So it does not mix the hot and cold water. The Cobra EL-JOE is a pillar tap with ½” BSP female inlets. The unit is powered by a single 9V battery that is housed inside the tap. Converting the unit to 230V is easy and there are various options available, see later on in the article. The tap comes with a solenoid but not the batteries. The batteries is the responsibility of the buyer.


  • Single temperature (cold or pre-blended water).
  • Operating pressure 0,3 to 8,0 bar
  • Maximum temperature 70ºC.
  • Flow time can be set between 1 to 60 seconds.
  • The tap will flow whilst sensing proximity of hands.
  • Maximum time period of activation 60 seconds.
  • Super capacitor power supply – CO-TRANS3-M
  • For backup power during power failure use the CO-TRANS3-B/U
  • Power supply to 10 taps use CO-EL-TRANS
COB-EL-JOE sensor tap diagram

Dimensions of the Cobra EL-JOE electronic sensor tap

Using 230V mains power with the Cobra EL-JOE

There are four accessories that can be added to the tap so it operated on mains 230V power. These units are of industrial nature so they are expensive to be used in low traffic environments. In high traffic areas these accessories are very cost effective.

  • CO-EL-TRANS3-M: This unit is the base unit can can supply power to three taps simultaneously. You need to remove the 9V battery if mains is used.
  • CO-EL-TRANS3-B/U: This is the backup power supply unit in the event that there is a power failure. It operates as a UPS. For critical installations where the factory needs to go on (even hospitals), this is sometimes a necessity.
  • CO-TRANS: This is a large unit that can provide power to 10 Cobra EL-JOE taps.
  • CO-TRANS-UP: A uninterrupted power supply for the CO-TRANS when using 10 or less EL-JOE taps.
cobra el-joe power supply mains

Mains power supply unit for up to 3 CO-EL-JOE sensor taps

backup power supply cobra taps

Backup power supply for the Cobra EL-JOE taps

multiple sensor tap power supply

Power supply for up to 10 EL-JOE taps.

uninterrupted power supply

Uninterrupted power supply for 10 or less taps.


Using the sensor tap with hot water

The Cobra EL-JOE does not mix hot and cold water. So it does not have an internal thermostatic mixer. If you require hot water for your users there are various options available. Firstly you can set the temperature of your hot water supply down so the water does not exceed 55°C (131°F). Actually it is better that the water is lower than 45°C (113°F). If this is not possible the following thermostatic mixers can be installed.

  • WC-15/3 – Can supply mixed water for up to three basins. Temperature limitation can be set to 55°C.
  • GR-THERM – Supply mixed water to one basin. Temperature limit can be set to 55 °C
  • CO-EL-X60  – Mechanical mixing of hot and cold water from a balanced supply. No temperature limitation. Final temperature is determined by hot and cold water pressure and flow rate.
  • CO-KD2-204 – Large volume thermostatic mixing valve. Usually used for washrooms with showers and baths and multiple basins. Usually connected to the whole room rather than just a single basin.
thermostatic control valve basins

Thermostatic valve for mixing hot and cold water for up to 3 basins.

thermostatic valve hot cold water mixer mixing

Thermostatic hot cold mixer for single hand wash basins

mechanical mixing device hot cold water basins zambia

Mechanical mixing device for taps. No temperature control