Square D Schneider Electric Time Delay Relays

Time delay relays are used in industrial applications that require time-delayed switching, such as starting a motor or controlling a load. In a standard control relay, contacts close immediately when voltage is applied to a coil, and open immediately when voltage is removed. In some applications, it is desirable to have the operation of the contacts delayed following voltage being applied or removed. On-delay timers begin when voltage is applied. When the time has expired, the contacts close and remain closed until the voltage is removed from the coil. If the voltage is removed before time-out, the time delay resets. When using off-delay timers, nothing happens when voltage is applied. Closing the control input causes the contacts to transfer. Opening the control input causes time to begin and the contacts remain closed. On time-out, the contacts transfer. Closing the control input prior to time-out causes timing to reset. Removing voltage prior to time-out resets the timing and opens the contacts.

Schneider Electric Harmony timer relays are designed to time events in industrial automation systems by opening and closing contacts before, during or after a set period of time. They are specifically designed for hard-wired logic automated systems to complement the functions of industrial PLCs. The wide range of timer relays with different timing functions, wiring options and mounting options are suitable for a wide range of applications including: buildings, machines, HVAC and water facilities.