K25 is a dual circuit energy saving smart switch, it can serve the primary and auxiliary circuits of a single space at the same time.

  • Primary Circuit (A): Fixed time or prohibited control capability.
  • Auxiliary Circuit (B): Control using button switch.

The internal clock of the K25 is used by both the fixed time and delayed time control.

  • Aside from its built in button, external classic button switches can also be connected for multiple access to the same lighting circuits.
  • The K25 is designed with dual circuits and can be used in two ways. One way is to have circuit B work in tandem with circuit A and both will be fixed time; the second way is to have circuit B operate with a button switch and work as delayed auto off.

K25 Demo

Application Spaces





Elevator Lobby

Elevator Lobby



System Diagram

K25 system diagram

Main Circuit

Primary circuit three modes of operation:
Preset time off

Preset On & Off: Works just like a timer with a preset on and off time.

Restricted period Prohibited Period:
  • Lights can only be turned on manually, choice of turning off using sensor or upon a preset time.
  • The button is disabled during the prohibited period.
Multiple preset off times

Multiple preset times during the day where the lights will be turned off.

Auxiliary Circuit

Unrestricted Use, No Delay
Manual on, manual off

Operate anytime, there is no delay when turning off.

Unrestricted Use, Delayed Off
Manual on, manual off with delay

Operate anytime, but if user forgets to turn off, will automatically turn off after a certain delay.

Sync With Primary Circuit
Sync with primary circuit

Works in sync with the primary circuit but for a secondary load.

Hallways & Restrooms (Dual)

Primary Circuit: Fixed time off with dimming. Auxiliary Circuit: User can manually turn lights on anytime, and turn lights off anytime, if they forget it will turn off automatically after a certain delay.

Hallways & Restrooms (Single)

Peak Period: Fixed time off with basic dimming level. Off-Peak Period: User can turn lights on anytime, lights will delay then auto off.


When classes start, lights are manually turned on; when classes end, the lights are manually turned off, but if the user forgets, there are several preset times where the lights will auto turn off.

Lights on:
When needed, the lights are turned on manually by the occupant. When no one needs to use the lights then it won't auto turn on.

Lights off:
To avoid having the lights left on, there are several times in a day where the lights will be turned off; e.g. after classes, noon break, evening.


  • Primary Circuit Capability: Night Prohibitions on the Main Dorm Lights
  • During the day, lights is free to use and can be controlled manually.

    At night, the main lights are turned off and prohibited from use.

    Wiring Changes