Eaton NRX Series User Manual

25
Instructional Book MN01301003E
Effective July 2011
Series NRX Low Voltage Power (Air)
Circuit Breakers User Manual
EATON CORPORATION www.eaton.com
Left accessory tray
The left accessory tray will accommodate a maximum of four devices
as follows:
•
Zero, one, or two shunt trips (ST)
•
Zero or one undervoltage release (UVR)
•
Combination (one ST and one UVR)
•
Zero or two overcurrent trip switches (OTS)
Right accessory tray
The right accessory tray will accommodate up to six 2a/2b auxilary
switch combinations.
Shunt trip (ST)
The shunt trip opens the circuit breaker instantaneously when its coil
is energized by a voltage input.
Undervoltage release (UVR)
The undervoltage release opens the circuit breaker when its supply
voltage falls into the range of 35–60% of rated voltage. If the release
is not energized to 85% of its supply voltage, the breaker cannot be
closed electrically or manually.
Overcurrent trip switch (OTS)
An overcurrent trip switch (bell alarm) provides an electrical indication
when a circuit breaker trips as a result of the trip unit reacting to an
overcurrent condition. Opening as a result of a circuit breaker’s manual
open button, shunt trip, or undervoltage release does not cause
the overcurrent trip switch to operate. Overcurrent trip switches are
available in two switch combinations only.
Auxiliary switch
An auxiliary switch provides remote electrical indication if the circuit
breaker is open or closed. Each switch has one normally open (“a”)
and one normally closed (“b”) type contact. Auxiliary switches are
available in two switch combinations only.
Other internal electrical devices
There are three types of internally mounted electrical devices:
•
Spring release
•
Latch check switch
•
Motor operator
Spring release (SR)
The spring release (closing coil) remotely closes the circuit breaker
when the coil is energized by a voltage input. When the spring release
is used in conjunction with a latch check switch, the closing spring
must be fully charged and the trip latch reset (not held in the tripped
position) for the SR to operate. If these conditions are not met, the
close signal will be ignored until it is removed and re-applied.
Latch check switch (LCS)
A latch check switch indicates when the circuit breaker is “ready to
close.” Two versions of the LCS are available:
1. The LCS wired to the spring release will not permit activation of the
spring release until the circuit breaker is fully charged and the trip latch
is reset.
2. The LCS used for remote indication consists of one Form C contact
wired to the circuit breaker secondary contacts for integration into
external control schemes.
ote:N Wiring the LCS for remote indication directly in series with the
SR accessory is not recommended as this will override the “anti-pump”
feature.
Motor operator
A motor operator is an electric motor assembly internally mounted in
the circuit breaker. It charges the closing springs electrically for remote
or local operation. The motor operator can be factory or field installed.
Mechanical devices
The following are optional mechanical type accessories:
•
Pop-out trip indicator, non-interlocked and interlocked
•
Operations counter
•
Off key lock
•
Pushbutton cover
•
Prevent close cover
•
Lockout cover
•
Cassette safety shutters
•
Door escutcheon
•
IP55 waterproof cover
•
Mechanical interlock

Eaton NRX Series Specifications

General

Brand	Eaton
Model	NRX Series
Category	Circuit breakers
Language	English