Datasheet
www.e-t-a.de
19
Thermal-magnetic circuit breaker 3120-N...-...M1-...
1930
 1
3120-N...-...T1-... Thermal Circuit Breaker
Description
Typical applications
The 3120-N...-...M1-... thermal-magnetic circuit breaker/switch  
combination unites overcurrent protection and the function of an ON/
OFF switch within a single component. The integral thermobimetal 
ensures ideally matched overload protection. The magnetic trip mod-
ule trips the circuit breaker/switch combination at overload currents 
from four times rated current within milliseconds. 
The 3120-N...-...M1-... meets the fire resistance requirements to 
EN 60335-1: 2007-02 Household and similar electrical appliances 
– Safety.
Electric motors, household appliances and office machines, electrical 
tools, power supplies, charging rectifiers
Current ratings and internal resistance values
Current rating 
(A)
Internal resistance per pole (Ω)
thermal-magnetic thermal 1.15 -1.38 x I
N
0.1 165  94
0.2 42.5  24
0.3 20.2  12
0.4 9.7  5.40
0.5 7.17  4.30
0.6 4.9  3
0.8 2.65  1.50
1 1.49  0.9
1.2 1.25  0.7
1.5 0.74  0.45
2 0.49  0.29
2.5 0.20  0.0785
3 0.14  0.0595
3.5 0.114  0.0565
4 0.092  0.0435
5 0.06  0.0325
6 0.043  0.0215
7 0.030  0.0215
8 0.029  0.02
10  0.021  0.02
12 < 0.02  < 0.02
14 < 0.02  < 0.02
15 < 0.02  < 0.02
16 < 0.02  < 0.02
Dimensions – magnetic trip module
blade terminals
6.3 x 0.8
21
0.826
flat head screw 
M3.5x6 for mains 
connection 
tightening torque 
max. 0.8 Nm
Dimensional drawings of the 
standard version of 3120-N 
please see page 6-8
10
18
14
30
9
0.393
1.181
0.354
41
3.5
15.5
0.708
0.551
1.614
0.137
0.610
21
11
I 
>
line
12(i) 22(i)
12(k) 22(k)
12
21
11
I 
>
line
12(i)
22(i)
12(k)
12
11
I 
>
line
12(i)
22(i)
12(k)
12
therm.-magn. protection on one pole
therm.-magn. protection on one pole
thermally protected on the other pole
therm.-magn. protection on one pol
e
unprotected on the other pole
Schematic diagrams
3120-N...-... M1-...










