On the Elkay Technical helpline we get asked a variety of questions in relation to energy management switches and controls. One question that is often asked is ‘What is the difference between 2 wire and 3 wire products?
Essentially when we talk about 2 or 3 wire we are referring to the master unit only in the Energysense, Energystyle and Energyoutdoor ranges. The Master is the unit that is positioned where the switch live is connected to the load.
On a 3 wire master there is a live (live in), a switch live (live out) and a neutral connection. There is also a blank terminal which is the trigger line and is for use with the slaves. A slave must be connected to a master unit with a three core connection utilizing the live, switch live and trigger terminals.
The master unit receives its own power because it is connected to the mains power and is therefore the easiest to set up. At Elkay we recommend that where possible the 3 wire master is chosen especially if it is possible to get a neutral to the switch position.
In contrast, the 2 wire master have a live and switch live connection only and is also used with slaves. These are perfect for retro-fitting where there is no possibility of getting a neutral to the switch position. However they must also utilize a three core connection between the master and slave units to work effectively. This often creates a common problem as people think that they can connect the whole system via 2 wires only so causing issues down the line.
Another issue that crops up with the Energysense, Energystyle and Energyoutdoor ranges is linking 2 wire masters together. This does not work as the masters will send signals to each other and therefore causing the load to be permanently on, in this situation slaves masters must be used.
Finally for those of you that have parallel wiring and only 2 cores between switches, i.e. you are replacing parallel wired Columbus pneumatic timers. Then visit your local wholesaler and ask for Elkay Energybasics which is an all in one system. Each timer acts as its own stand alone timer and is also available as 2 wire and 3 wire master.
If you have any further questions, please contact Elkay Technical Helpline on 01675 468222.