NR21 IDEC Corporation, NR21 Datasheet - Page 11

• Manufacturer Part Number: NR21
• Description: Plug-In Base; DIN Rail Mount; NRA Series Circuit Breakers; NRA Series
• Manufacturer: IDEC Corporation

Specifications of NR21

• Brand/series: NRA Series
• Mounting Type: DIN Rail Mount
• Lead Free Status / Rohs Status: RoHS Compliant part
• For Use With: NRA Series Circuit Breakers

www.idec.com
General
IDEC’s circuit breakers have been developed for the protection of electrical
circuits and small-sized electrical equipment and provide excellent protection
against overloads and short-circuits.
Additionally, IDEC’s circuit breakers are designed to suit specific needs. Each
series offers unique circuit protection characteristics and a choice of actuator
styles.
IDEC’s Circuit Breaker Features
• Various models are available with different internal circuits, tripping charac-
• 1- to 3- multi-pole
• Inertia delay
• Auxiliary contacts and alarm contacts
• The electromagnetic tripping system is not affected by ambient temperature
• Safe trip-free mechanism
• Vibration- and impact-resistant design
• When using accessories such as plug-in bases, flush plates, and colored
Mounting Instructions: Installation Angle
Designed to be mounted on a vertical surface, the circuit breakers should be
mounted on a surface within 10° of the vertical plane. If the circuit breaker is
mounted on a horizontal surface or at any angle other than the specified
angle, its characteristics will be changed.
Multi-Pole Assemble
Multi-pole types such as 2- or 3-pole should be assembled by IDEC.
Because of their characteristics, 1-pole breakers cannot be com-
bined to produce multi-pole units.
teristics, and rated currents
caps, a variety of mounting styles is possible — such as DIN rail mount-
ing, snap mounting into panel cut-outs, and color-coded arrangement on
the panel
Load B
Load B
Circuit Breakers
Description
Load A
Load A
USA: (800) 262-IDEC or [phone], Canada (888) 317-IDEC
Load
Instructions: All Series
Internal Circuits Overview
Series Trip
This is the most common circuit breaker, providing excellent overload and short circuit
protection. It can also be used as an ON/OFF switch.
Series Trip with Auxiliary Contact
Since the auxiliary contact operation is interlocked with the ON/OFF of the main contactor,
circuit breaker operation can be monitored by a lamp or buzzer. This circuit breaker can
also be used to control auxiliary circuits up to 250V AC/5A (resistive load).
Series Trip with Alarm Contact
Since the alarm contact is electrically independent of the main contactor, but actuates
when the protective element operates. The alarm can be used with a lamp or buzzer to
monitor trip operations, and can also be used for controlling alarm circuits. The contact
rating is 250V AC/5A (resistive load).
Applications
The IDEC NRA circuit breaker series features superior overload and short-cir-
cuit protection. Many combinations of protection mechanisms and internal
circuit connections enable wide applications.
• Precision measuring instruments: electronic counters, projection
• Electronic communication devices: facsimile machines, computers,
• Industrial machinery: printers, elevators, cranes
• Chemical and food industry machines: vacuum devices, wrappers,
• Machine tools: mill grinders, drills, presses
• Business machines: automatic vendors, medical equipment, beauty
• Other: office equipment, air-conditioners, conveyor belts, and many more
How the Breaker Operates
IDEC’s hydraulic magnetic circuit breakers operate like a solenoid coil. The
coil unit consists of an oil-filled tube with a metal core at one end and a pole
piece and armature at the opposite end with a spring in between.
When a current load passes through the coil winding, it creates a magnetic
field. As long as the current load is either at or below the nominal rating of
the breaker, the metal core will remain stationary.
If the current load increases beyond the nominal rating, the strength of the
magnetic field causes the core to move toward the pole-end of the tube. The
oil viscosity regulates the core’s movement through the tube, thereby regulat-
ing the time delay. As the percentage of current load increases, the required
trip time of the breaker decreases and vice versa.
When the current reaches the overload rating, the metal core will meet the
pole piece at the opposite end of the tube. At this point, the armature is
attracted to the same pole piece, tripping the breaker.
In case of sudden short circuit, the magnetic field created will instantly trip
the breaker.
instruments, oscilloscopes, industrial instrumentation, and analytic
devices
recorders
centrifuges, agitators
salon equipment, entertainment games
Circuit Example
Instructions
N-29
N