hager h3+, Communication Instruction Manual, Page: 33 / 127

33
6LE005550A
Function of the Energy trip unit
3.2 Protection function
tr adjustment range (s)
0.5 1.5 2.5 5 7.5 9 10 12 14 16
The trip time tolerance for long time delay protection is -20% + 20ms to 0%
+ 30 ms.
Example:
For tr = 5 s and I = 6 x Ir, the trip time for long time delay protection will be between
3.98 s and 5.03 s.
Modelling conductor heating by thermal imaging
LSnI, LSI, LSIG and Energy electronic trip units have a thermal imaging function.
This function models the heating and cooling of the electrical conductors. It enables
the Energy circuit breaker to protect the conductors against current overloads by
taking into account the thermal state of these conductors.
In the presence of current, the h3+ electronic trip units model the heating of the
conductors.In the absence of current, the h3+ electronic trip units model the cooling
of the conductors.
a)
100%
I
b)
1)
t
2)
Trip units with and without cooling
Trip units with and without consideration of conductor cooling
Key:
a) Trip unit with consideration of cooling
b) Trip unit without consideration of cooling
1) Tripping of trip unit type a)
2) Tripping of trip unit type b).
The example above clearly shows how trip unit a) trips earlier than trip unit b)
therefore providing optimum protection to the conductors.
h3+ electronic trip units are type a) trip units.
In addition, they take into account the cooling of the conductors not only before,
but also after tripping.
The cooling phase lasts between 1 and 35 minutes depending on the tr time delay
setting.
Note
The thermal imaging function of the h3+ electronic trip units cannot be deactivated.