Operating instructions

Introduction to STS2 Operations 53
8.2.3 Transfer Inhibit
For a transfer to be completed between input sources, the sources must meet certain parameters, or
the transfer cannot take place. Uninterrupted transfer between sources is inhibited due to input
source failure, sources out of sync, switch failure, or the unit is in bypass mode.
8.2.4 Bypass
The static transfer switch can be manually bypassed to allow the power from a source to directly
flow to the output load. This bypass allows the unit’s electronics to be serviced without dangerous
voltages being present.
The STS2 includes key-interlocked maintenance bypass breakers that allow either input source’s
electronics to be bypassed for maintenance without interruption of power to the load. The mainte-
nance bypass allows all electronics to be isolated from the input, output, and bypass connections.
Bypass instructions are available from the touch screen and are discussed later in this manual.
8.3 Operator Controls
The STS2 is equipped with an interface to configure and monitor the unit either locally or remotely.
The Color Graphical Display is a touch screen LCD that provides a color diagram (Mimic) that dis-
plays the current status of the unit. System parameters are displayed and help is available to define
events. See Figure 32 below and Figure 31 on page 49. The touch screen menus allow the opera-
tor to initiate source transfers, view event and history logs, and view bypass and other operational
instructions.
Figure 32 STS2 Touch Screen Display
Touch screen control buttons allow you to reset alarms, silence the audible alarm, review configura-
tions, event and history logs, preferred source, startup and bypass procedures, and the help menu.
Qualified personnel, with a password, can use these menus to configure parameters, select a pre-
ferred source, and do manual source transfers.
LED display units do not have the color LCD display. Instead of the touch screen, these units are
monitored by a series of LEDs and controlled by a series of push buttons.
Both units can be accessed from a terminal, or a PC running terminal emulation software, that is
attached to the unit. Through the RS-232 access, you can monitor and configure the unit, plus
remotely select a preferred source. See 12.1 - Using the RS-232 Port on page 70 for instructions
on using the RS-232 interface.
Mimic
Event Display
Event controls
Display Panel
and
Help Screen
Menu Options