Static Transfer Switch (STS)
A static transfer switch is a semiconductor system that can carry out an automatic or manual transition between two single phase or three phase synchronized AC sources, without making the power cut perceptible. The power transfer is carried out via thyristors.
The primary function of the static transfer is the uninterrupted power supply of the load when a problem occurs in the sources that is powering the system. One of the input sources of the static transfer switch is the "preferred source" and the other the "alternative source". The preferred source is the primary source of power supply. In other words, if both sources are within the limits the load will be supplied via the preferred source. If there is any kind of problem in the preferred source the load will be transferred to the alternative source in less than 1/4 cycle. The preferred and alternative sources and the voltage limits are adjustable.
STS technical specifications: The static transfer switch can be used as singular system in every area where uninterrupted energy is very important. These are hospitals, medical centers, military systems, data processing centers and airports.
Every uninterrupted power supply contains a static transfer switch that ensures the transfer between the inverter and bypass source. The preferred source for online systems are inverters. Bypass lines however are used as alternative sources. Besides that the static transfer switch can be used as singular system in every area where uninterrupted energy is very important. These are hospitals, medical centers, military systems, data processing centers and airports.