22 • vacon
description of parameters
Tel. +358 (0)201 2121 • Fax +358 (0)201 212 205
DC Brake Parameters (M2 -> G2.3.3)
2.3.3.1 DC-brake
current
Defines the current injected into the motor during DC-braking.
2.3.3.2
DC-braking time at start
DC-brake is activated when the start command is given. This parameter defines the
time before the brake is released.
2.3.3.3
DC-braking time at stop
Determines if braking is ON or OFF and the braking time of the DC-brake when the
motor is stopping. The function of the DC-brake depends on the stop function,
parameter 2.4.2.
0
DC-brake is not used
>0
DC-brake is in use and its function depends on the Stop function,
(
). The DC-braking time is determined with this parameter
Par. 2.4.2 = 0; Stop function = Coasting:
After the stop command, the motor coasts to a stop without control of the frequency
converter.
With DC-injection, the motor can be electrically stopped in the shortest possible time,
without using an optional external-braking resistor.
The braking time is scaled according to the frequency when the DC-braking starts. If
the frequency is
≥
the nominal frequency of the motor, the set value of
determines the braking time. When the frequency is
≤
10% of the nominal, the
braking time is 10% of the set value of
Figure 4. DC-braking time when Stop mode = Coasting.
f
n
fn
t
t
NX1
2
K
2
1
0,1 x fn
R
U
N
S
T
O
P
RUN
STOP
O
u
t
p
u
t
f
r
e
q
u
e
n
cy
M
o
t
o
r
s
p
e
e
d
Output frequency
Motor speed
DC-braking ON
D
C
-
bra
k
i
n
g
O
N
f
o
u
t
fout
t = 1 x par. 2.3.3.3
t = 1 x par. 2.3.3.3
