Hubbell LX-440 Manual

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Transfer Switch

Page 3 of 16 Pages

1.0 Introduction

Hubbell’s non-automatic, LX-440, and automatic, LX-450, transfer switches are available in 2, 3, and 4

pole models with ampere ratings of 100 to 1250 A. The transfer switches are available as open type or

in an individual cabinet.

The automatic transfer switch has a Solid State Transfer Control Module, LX-301, that monitors voltage

and controls the transfer to and from the normal and emergency sources. The non-automatic transfer

switch has a selector switch to manually initiate transfer. A handle is included with all transfer switches

to manually close the normal or emergency contacts.

PRM

optional

Control

Module

(LX-301)

Transfer Control

Relay Board

Switching

Mechanism

To engine

start contacts

(If generator backup)

Emergency

Source

Normal

Source

TSE

TSN

To load

Normal Source

Transformer

Emergency Source

Transformer

Figure 1-1 Block Diagram of automatic transfer switch showing one phase