Braking Time - KEB COMBIVERT F4-S Serie Manual De Instrucciones

Braking time

Formulas
K = 0,25 for motors
0,20 for motors 2,2 to
0,15 for motors 5,5 to 11 kW
0,08 for motors 15 to 45 kW
0,05 for motors
On period c.d.f.
The braking time is adjusted on the frequency inverter. If the selected
time is too short the KEB COMBIVERT/COMBIDRIVE automatically
switches off and displays the error message OP or OC . The following
formulas allow an approximate determination of the braking time.
1. Braking time without braking resistor
(J
t =
Bmin
9,55 • (K • M
Validity range:
(field weakening range)
3. Peak braking power
P =
B
Condition:
to 1,5 kW J =
M
4 kW J =
L
n =
1
n =
2
> 45 kW
n =
N
M =
N
M =
B
M =
L
t =
B
t =
Bmin
t =
Z
P =
B
P =
R
ON period c.d.f for cycle time t
t
B
c.d.f =
t
Z
Accessories
+ J ) • (n - n )
M L 1 2
+ M )
N L
n > n
1 N
M • n
B 1
9,55
<
P P
B R
Moment of intertia of the motor
Moment of intertia of the load
Motor speed before deceleration
Motor speed after deceleration
(Stand still = 0 rpm)
Motor rated speed
Motor rated torque
Braking torque (required)
Load torque
Braking time (required)
Minimum braking time
Cycle time
Peak braking time
Peak power of the braking resistor
<
120 s
Z
• 100 %
f
t
Z
2. Braking torque (required)
(J + J ) • (n - n
M L 1
M =
B
9,55 • t
B
Condition: M < 1.5 • M
B
f < 70 Hz
4. Braking time with braking resistor
(J + J ) • (n - n )
M L 1 2
t * =
Bmin
(
9,55 • K• M + M
N
Validity range: n > n
1 N
P • 9,55
R
<
Condition: M
(n - n )
1 2
<
f 70 Hz
<
P P
B R
[kgm 2 ]
2
[kgm ]
-1
[min ]
[min -1 ]
-1
[min ]
[Nm]
[Nm]
[Nm]
[s]
[s]
[s]
[W]
[W]
ON period c.d.f for cycle time t
t
B
c.d.f = • 100 %
120 s
t
t
B
)
2
- M
GB
L
N
P • 9,55
R
)
+
L
(n - n )
1 2
• (1,5 -K)
N
> 120 s
Z
GB - 21