Specifications

Liebert STS2 Static Transfer Switch
The Liebert STS2 Static Transfer Switch provides an
automatic, seamless transfer between the outputs of two
independent UPS systems and the input of a critical load in
a dual-bus power system. If the primary UPS should fail, the
switch will automatically transfer the loads to the surviving
UPS. For redundancy, the Liebert STS2 features three
separate, self-correcting logic modules. Each controller is
capable of working independently and each helps monitor
the other two. Available in capacities ranging from 100 up
to 1000 amps.
True Front-Access Design
All mechanical and electronic components of the
Liebert STS2 are accessible from the front of the unit. This
gives you several immediate benefits:
Greater freedom in system design. The Liebert STS2 can
be placed adjacent to or in back of other equipment. It
can also be placed against a wall or partition.
Simplified installation, with ample space for cable
connections through top and bottom access plates.
Less floor space required for maintenance access.
Simplified maintenance, with all key components
visible, serviceable and removable from the front of
the unit, without the need to shut down the connected
load.
Other Features Of The Liebert STS2:
Internal CANBUS protocol provides high-bandwidth
communication between system components via
twisted-pair cables. Options can be added as simple
network nodes.
Internal dual-bus control power.
Simplified installation and maintenance.
Full range of communications options to fit any
monitoring strategy.
Three-pole switch configurations.
Optimized Transfer option uses the patented Liebert
static transfer control algorithm to eliminate downstream
transformer inrush saturation. Meets CBEMA and ITIC
standard for critical loads.
True Internal Redundancy
The Liebert STS2 has triple-redundant logic. Each DSP
controller is capable of working independently, and
each helps monitor the other two. If one malfunctions,
the other two lock it out. Each controller has power
feeds from both power supplies.
The two power supplies feature true dual-bus power
distribution. Both have dual inputs, one from each
AC input source. All power connections have diode
protection, so that internal or external faults cannot
propagate. The result is a rugged, fault-resilient
package that is optimized for real-world applications.
Easy-To-Use Color
Touch-Screen Interface
The controls of the Liebert STS2 are
intuitive and simple. The pop-up menus
are easy to understand and provide a
wealth of operational and diagnostic
information.
The color LCD monitor is divided into
three segments. In addition to a system
mimic diagram, there is a status/
alarm panel and a section dedicated
to operator instructions and menus.
You benefit from improved operator
effectiveness, reduced training time,
and less chance of operator error.
The Key To High-Availability Power.
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