MC30-BC
Doc. N°
MO-0365-ING
Copyright 2008
FW 980.09.01.X
Date
15.06.2022
Rev.
1
Pag.
10
of
37
3. Functions and Settings (Function)
3.1 - T> (F49) - Thermal Image protection level
FuncEnab
→
Enable
[Disable / Enable]
Options
→
No Param
No Parameters
TripLev
→
Tal
50
%Tb
(50
110)
step 1
%Tb
→
Tst
100
%Tb
(10
100)
step
1
%Tb
Timers
→
No Param
No Parameters
Description of variables
FuncEnab
: If disable the function is disactivated.
Tal
: Thermal prealarm temperature.
Tst
: Reset level.
Trip when
: The temperature
exceeded for time “tI>”.
When the function is tripped
:
Signalization
=
Led “Trip” is illuminated
Last Trip
= Is recorded
Led reset when
: Return in normal condition
Warming-up is
computed proportionally to the square of the largest phase current “I”.
-
Allowed overloading time
(See Curve)
The trip time delay “
t
”
of the thermal element, depends on the warming-up time constant
“
tw
”
, on the previous thermal status (Ip/In)
2
, on the admissible continuous overload (Ib) and, of
course, on the actual load (I)
tw
=
Warming-up time constant
(60-3600) s.
I
=
Largest of the three phase currents
Ip
=
Preheating current: Steady-State Current corresponding to the thermal status
existing at the moment when the current is increased to the overload value “I”
Ib
=
Continuously admissible current
(50-130) %In, step 0.1%In
In
=
Rated primary current of phase C.Ts
n
=
Natural logarithm
Reset takes please when the simulated temperature drops below the programming level [Tst].
An alarm
signal is issued when the computed warming exceeds the set percentage “Tal”
of the Full
Load temperature “Tb”.
:
where
(Ib/In)
(I/In)
(Ip/In)
(I/In)
tw
t
2
2
2
2
−
−
=
n
