NR21 IDEC Corporation, NR21 Datasheet - Page 7

• 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

Coil Data for Series Current Trip at 25
Voltage Drop Due to Resistance or Impedance
The internal resistance or impedance of a circuit breaker tends to be larger for
a smaller rated current. Therefore, when circuit breakers with a small rated
current are used, voltage drop should be taken into consideration. Internal
resistance also varies with time delay curves, even at the same rated current.
This should also be considered during installation.
Time Delay Curve and Ambient Temperature
Since NRA series circuit breakers employ an electromagnetic tripping system,
the rated current (trip current) is not affected by the ambient temperature, but
the time delay varies with the oil viscosity in the tube. Lower oil viscosity at
higher temperatures results in shorter delay; whereas at lower temperatures,
the delay will be prolonged. The time delay curves, shown starting on page N-
7, are at 25°C. Time delay curves can be corrected.
0.30A
0.50A
0.75A
1A
2A
3A
5A
7.5A
10A
15A
20A
25A
30A
www.idec.com
Current
Rated
Tolerance ±25% (up to 20A), ±50% (25A and over).
Curves AD, MD
DC Resistance
0.0066
0.0048
0.0043
0.0036
0.036
0.017
0.012
9.67
3.24
1.45
0.90
0.21
0.09
Circuit Breakers
Curves AA, BA,
AC Impedance
(50/60Hz)
0.0068
0.0048
0.0043
0.0041
0.092
0.036
0.018
0.012
9.82
3.36
1.49
0.92
0.21
MA
USA: (800) 262-IDEC or [phone], Canada (888) 317-IDEC
˚
C
Resistance and Impedance Characteristics
0.01
0.01
100
100
0.1
0.1
10
10
0.001
0.001
1
1
Coil Resistance at 25°C
400
200
100
80
60
40
Temperature Correction Curves
–40
0.01
0.01
–20
Ambient Temperature (°C)
0.1
0.1
Coil Resistance ( )
0
Impedance ( )
Curves AD, MD
Curves AA, BA, MA
25
1
1
Curves AD, AA, BA
(on 125% rated current)
50
70
10
10
90
100
100
NRA Series
N-9
N