Introduction; General Information - Eaton Magnum Air MWN-408 User Manual

1 INTRODUCTION

1.1

General information

The Magnum Air Circuit Breaker is a fixed or drawout air
circuit breaker design utilizing an electronic tripping
system. It is designed and tested for use at nominal
voltages of 380-440 and 500-690 volts ac. Magnum
circuit breakers are available in three physical frame sizes
with continuous current ratings from 800 through 6300 A.
and interrupting capacities from 42 kA to 150 kA.
The three physical frame sizes have common height and
depth dimensions, differing only in width (Figure 1-1).
The circuit breaker nameplate provides complete rating
information. All Magnum circuit breakers are 100
percent rated, and are built and tested in an ISO 9002
certified facility to applicable IEC and BS standards
(Table 1-1, Figure 1-2 and Figure1-3). In addition, the
Magnum circuit breaker carries a full third party KEMA
certification for both short circuit and endurance test
requirements.
Magnum circuit breakers use a rigid frame housing of
engineered thermoset composite resins which has high
strength structural properties, excellent dielectric
characteristics and arc tracking resistance.
Figure 1-1: Family of Magnum Low Voltage Air Fixed and Drawout Circuit Breakers (800-6300 Amperes)
1812.900A
Double-wide Fixed
The drawout Magnum circuit breaker is a through-the-
door design having three breaker positions with the
compartment door closed (CONNECT, TEST,
DISCONNECT) and one position out of its compartment
on extension rails (REMOVE). The operating mechanism
is a two-step stored energy mechanism, either manually
or electrically operated.
When withdrawn on captive compartment cassette
extension rails, Magnum circuit breakers can be
inspected, accessory items added, and minor
maintenance performed. The inside of the compartment
can also be inspected with the circuit breaker on its
extension rails.
PLEASE READ AND UNDERSTAND THESE
INSTRUCTIONS BEFORE ATTEMPTING TO UNPACK,
INSTALL, OPERATE OR MAINTAIN THIS
EQUIPMENT. STUDY THE BREAKER AND ITS
MECHANISM CAREFULLY BEFORE ATTEMPTING
TO OPERATE IT ON AN ENERGIZED CIRCUIT.
Standard Frame Fixed
NOTICE!
Narrow Frame Fixed
Magnum
5