4.28 Restart Inhibit for Motors (ANSI 66, 49
Rotor
)
443
7UM62 Manual
C53000-G1176-C149-3
4.28
Restart Inhibit for Motors (ANSI 66, 49
Rotor
)
Setting Ranges/
Increments
Starting CurrentBased
I
Start
/I
MOTnom
1.5 to 10.0
(Increments 0.1)
on Nominal Motor Current
Max. Permissible
T
MOT START
3.0 s to 120.0 s
(Increments 0.1 s)
Starting Time
Temperature
T
EQUAL
0.0 min to 60.0 min (Increments 0.1 min)
Equalization Time
Max. Permissible
n
WARM
1 to 4
(Increments 1)
Number of Warm Starts
Difference between
n
COLD
- n
WARM
1 to 2
(Increments 1)
Cold and Warm Starts
Extension of Time
k
τ
STOP
1.0 to 100.0
(Increments 0.1)
Constant at Stop
Extension of Time
k
τ
RUNNING
1.0 to 100.0
(Increments 0.1)
Constant at Motor Running
Minimum Restart Inhibit Time
0.2 to 120.0 min
(Increm. 0.1 min)
Restart Threshold
RestartTimes
Θ
Re.Inh
Θ
L max perm
n
COLD
1
–
n
COLD
---------------------------
⋅
=
T
Re.Inh
τ
ln
Θ
Hist
Θ
Re.Inh
------------------
(
)
⋅
τ
ln
Θ
Hist
n
COLD
⋅
n
COLD
1
–
-----------------------------------
(
)
⋅
=
=
T
Wait time
T
Equal
T
Re.In.
+
=
Meaning
:
Θ
Re.Inh.
Temperature threshold below which a
restart is possible
Θ
L max perm.
Maximum permissible rotor
overtemperature (= 100 % in operational
measured value
Θ
R
/
Θ
R Trip
)
n
COLD
Number of permissible starts in cold
condition
T
Wait time
Time after which a restart of the motor is
possible
T
Equal
Equalization time during which the thermal
replica is "frozen"
T
Re.Inh.
Time for the thermal replica to drop below
the restart threshold again, depends on:
Θ
Hist
History leading to the rotor temperature
τ
Rotor time constant (internally calculated)
