Manual LCO EXC3/ADV3 OTD | 03-2020 | 1.2 | en
Installation notes
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Maximum loading of circuit breakers
Importance of maximum loading
A circuit breaker is an automatically operated electrical switch that protects an electrical circuit from damage caused by overload or
short circuit. Unlike a fuse that must be replaced if it triggers, a circuit breaker can be reset (either manually or automatically) and
used further. Circuit breakers are available in different sizes and with different technical data.
The inrush current is a short increased peak current that occurs when an electronic control gear is switched on.
In electrical installations, numerous control gear are connected to one circuit breaker. The maximum loading of a circuit breaker
indicates how many control gear can be connected to the circuit breaker without triggering the circuit breaker because of the
summation of the different inrush currents. The value is calculated through simulation programs based on the circuit breakers
characteristic.
Information about the maximum loading can be found in Tridonic data sheets. The following table shows the data for LCO
as an example.
60/200-1050/100 o4a NF C EXC3
Automatic circuit breaker type
C10
C13
C16
C20
B10
B13
B16
B20
Inrush current
Installation Ø (in mm )
2
1,5
1,5
2,5
4
1,5
1,5
2,5
4
I
max
time
LCO 60/200-1050/100 o4a NF C EXC3
10
13
16
21
6
8
10
13
32 A
355 µs
Calculation of maximum loading
Tripping characteristics of circuit breakers
The load at which a circuit breaker triggers is defined by the height and the duration of the applied current.
The following table shows exemplary values for different circuit breakers (B10, B13, B16, B20).
Duration
[µs]
Current B10
[A
]
peak
Current B13
[A
]
peak
Current B16
[A
]
peak
Current B20
[A
]
peak
100
700
910
1,120
1,400
200
260
338
416
520
300
177
230.1
283
354
400
145
188.5
232
290
500
122
158.6
195
244
600
110
143
176
220
700
102
132.6
163
204
