Chapter 1 - General Description; Introduction - Liebert NETWORK POWER SWITCH 2 Installation Manual

User Manual
1 Chapter 1 – General description

1.1 Introduction

The Network Power Switch (NPS) is an automatic static transfer switch designed to provide fast automatic transfers
between two independent, synchronous/asynchronous AC power sources to provide continuity of AC power to critical
equipment, such as information technology equipment.
One of the two AC inputs is designated as the "preferred" source to which the Network Power Switch will connect the
load as long as the designated input source is within the acceptable limits. The Network Power Switch is designed to
transfer the output load to the "alternate "input source, as long as the alternate source is within the acceptable voltage
limits and the preferred source is not.
The Network Power Switch provides fast, break-before-make transfers to prevent interconnection of the two sources,
even under faulted source conditions.
The maximum sense and transfer times are within the tolerance of IEEE Standard 446 susceptibility curve for
information technology equipment to allow uninterrupted load equipment operation.
In case of overload, Network Power Switch gives the alarm. Under Short-circuit condition a fast acting semi conductor
fuse protects condition of the load.
The Network Power Switch is 2 pole switch to prevent objectionable currents in the earth due to separate grounding
systems for the two sources.
Manual Bypass Switch
The entire power static switch module is hot swappable. Before removing this module the load is transferred, without
break to any one of the source directly by using the Manual bypass switch. After replacing the static switch module, the
load is restored on static switch module, using the Manual bypass switch.
Block Diagram
(08/10)
N e t w o r k P o w e
N e t w o r k P o w
Fig 1.1 – Block Diagram of Network Power Switch
r S w i t c h 2
e r S w i t c h 2

Chapter 1 - General Description

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