Emerson Liebert STS2 User Manual

Page 3

One-Line Diagram

True Front-Access Design

All mechanical and electronic components of the Liebert

STS2 are accessible from the front of the unit for

installation and service—no side or rear access required.

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.

Designed for maintainability, with all key components

visible and accessible from the front of the unit,

without shutting down the connected load.

For units up to 600 amps,

the entire power and

control module can be

removed as an assembly.

A separate compartment

for option modules

provides safe and

convenient field access.

Source 1

Source 2

System Output

CB1

CB3

CB4

CB2

CB5

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.