Liebert POWER PROTECTION STATIC TRANSFER SWITCH User Manual

The logic contains three separate redundant logic modules. The modules contain the logic necessary 

to run the STS2 and control transfers and shunt trips under all circumstances, without any outside 

assistance once set-up and started properly.

An audible alarm is installed on the control board. This alarm is triggered by an alarm condition 

detected on the unit. The alarm can be turned off from the touch screen (Color Graphical Display 

units) or by a push button (LED Display units). Turning off the audible alarm does not clear or reset 

the condition that triggered the alarm. 

An RS-232 serial port is provided to allow an external terminal to be connected as another user inter-

face. See 12.1 - Using the RS-232 Port on page 76 for more information on using the RS-232 port.