hager hw+ User Manual

52 6LE008146B
Protection functions
4.2 Long Time Delay protection IEC 60255-151
The tripping time is limited by a thermal protection curve of the circuit breaker that reduces the
tripping time to prevent excessive overheating of the circuit breaker when the Long time delay
protection setting leads to a trigger time that is too long.
The following graphic illustrates the principle of tripping time reduction:
Reset time
The reset time works in the same way as the thermal memory. It allows the thermal eects of
overloads to be taken into account and allows the cables and power busbars to be protected
against overheating.
It is the time between the end of the detection of the overcurrent and the reset of the
protection time delay.
The reset time is dependent at times, meaning that the reset time depends on the value of the
current after the overload. This is the time required to reset the eect of the previous overload.
If a new overload appears before the end of the reset, the tripping time will be shortened.
The reset time factor is fixed. It is 40% x tr.
The reset time is calculated with the following equation:
I
t
Ir
t
Thermal protection curve
Eective curve SI I
0.02t
Theoretical curve SI I
0.02t

hager hw+ Specifications

General

Brand	hager
Model	hw+
Category	Circuit breakers
Language	English