IDEC NRBM Series Catalog

Circuit Breakers

NRBM Series

NRBM circuit breakers are the largest in rated current (1A to 50A) among the IDEC circuit breakers series. These small sized, high-efﬁ ciency breakers offer a variety of protection characteristics that can be widely employed for semiconductors, relay circuits, heater circuits, transformers, and solenoids.

Key features of the NRBM series include:

Excellent overload and short circuit protection

• Small size and high efﬁ ciency

• Life expectancy of over 10,000 operations

• UL1077 recognized Supplementary Protectors

• VDE Certiﬁ ed to EN60934

•

File No. E68029

General Speciﬁ cations

Protection Method Electromagnetic tripping

Internal Circuit Series current trip

Number of Poles 1, 2, 3

Rated Voltage 250V AC, 50/60Hz, 65V DC

Rated Tripping Currents Current trip: 1A, 2A, 3A, 5A, 7.5A, 10A, 15A, 20A, 25A, 30A, 40A, 50A

Rated Interrupting Capacity

Auxiliary Contacts / Alarm Contact

Reference Temperature 25°C

Ambient Operating Temperature –40 to +85°C (avoid freezing)

Insulation Resistance 100MΩ (measured with 500V megger)

Dielectric Strength

Vibration Resistance 100N (approximately 10G), 10 to 55Hz

Shock Resistance 1,000N (approximately 100G)

Life Expectancy 10,000 operations minimum (at 6 operations per minute)

Terminal Style

Weight

250V AC, 50/60Hz, 1,000A 65V DC, 1,000A

SPDT microswitch 250V AC, 5A (resistive load) 50V DC, 1 A (resistive load)

Between main circuit terminals: 2,000V AC, 1 minute Between main circuit and auxiliary contact: 2,000V AC, 1 minute

Main terminal: M5 stud Auxiliary contact/ alarm contact: Quick-connect tab 0.110” terminal

1-pole/100g 2-pole/200g 3-pole/300g

License #113434

Switches & Pilot Lights Display Lights Relays & Sockets Timers Terminal Blocks

Not suitable for branch circuit protection.

Circuit Breakers

893

NRBM Series

Circuit Breakers

Part Numbering Guide

NRBM series part numbers are composed of 6 part number codes. When ordering an NRBM series part, select one code from each category. Example: NRBM 1 1 11 F-30A-AA

NRBM 1 1 11 F — 30A — AA

Switches & Pilot LightsDisplay LightsRelays & SocketsTimersTerminal Blocks

j Poles k Internal

Part Number Codes: NRA Series

1-pole 1

j No. of Poles

k Internal Circuit

l Auxiliary and

Alarm Contacts

m Inertia Delay

n Rated Current

o Time Delay Curve

1. For NRBM series time delay curves, see page 897.

2. For NRBM series dimensions, see page 899.

3. Not suitable for branch circuit protection.

4. UL recognized, applicable standard: UL1077, “Supplementary Protectors.”

2-pole 2

3-pole 3

Series current trip 1

Without 00

With auxiliary contact 11 Auxiliary contacts change state with lever and/or overload condition

With alarm contact 21 Alarm contacts change state only with overload condition

Without inertia delay Blank

With inertia delay F

Rated current (current trip)

AC curves AA, BA,MA

DC curves AD, MD

l Auxiliary and

Circuit

Description Part Number Code Remarks

Alarm Contacts

1A, 2A, 3A, 5A, 7.5A, 10A, 15A, 20A, 25A, 30A, 40A, 50A

m Inertia Delay n Rated Current o Time Delay Curve

All multiple pole circuit breakers are simultaneous throw/simultaneous break. All levers are mechanically interlocked.

See page 897 for delay curves.

Circuit Breakers

894

Circuit Breakers

NRBM Series

Information About Circuit Breakers

Time Delay Curve Descriptions

Time Delay Curve NRBM Application

AD, AA Common curves used in molded-case circuit breakers.

MD, MA Suited for motor loads that draw high inrush currents lasting a considerable length of time.

With Inertia Delay (F) Designed not to trip on 20 times the rated current (peak value) for a duration of 8ms. Suited for transformer and lamp loads that draw steep inrush currents.

Inertia Delay Descriptions

Circuit breakers equipped with inertia delay do not respond to high inrush currents such as those produced by transformer, lamp, or motor loads, but perform speciﬁ ed interruption on rated overcurrents.

Inertia delay is available with time delay curves AD, MD, AA, BA, and MA.

Specify inertia delay by inserting an “F” in the part number as shown in Part Number Guide on previous page.

Response to overcurrent is quite fast. Suited for protection of semiconductor circuits with very little overload tolerance. If overcurrents are expected to ﬂ ow, fuses may be required according to the circuit characteristics.

16,000

14,000

12,000

10,000

8,000

6,000

Percent of Rated Current

4,000

2,000

12 34 567 8910

Pulse Width

Pulse Width (ms)

Pulse Peak Current

(duration)

Switches & Pilot Lights Display Lights Relays & Sockets Timers Terminal Blocks

1. P

ercent of Rated Current =

2. Based on sinusoidal or parabolic pulse proﬁle.

Pulse Peak Current

Protector Rated Current

x 100%

Notes

Multi-Pole

Multi-pole types such as 2- or 3-pole should be assembled by IDEC.

Because of their characteristics, 1-pole breakers cannot be combined to provide multi-pole units.

All multi-pole units are simultaneous break/simultaneous make, with levers mechanically interlocked.

Auxiliary and Alarm Contacts

Multi-pole units with auxiliary contacts will have one set of auxiliary contacts on the right-most breaker. Multi-pole units with alarm contacts will have one set of alarm contacts on the left-most breaker.

Circuit Breakers

895

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