Vacon 20 - Page 123

parameter descriptions vacon
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117
9
4.11 S
TOP
DC
CURRENT FREQUENCY
It is the output frequency at which the DC-braking is applied.
4.12 S
TART
DC
CURRENT TIME
DC-brake is activated when the start command is given. This parameter de
fines the time for how long DC current is fed to motor before acceleration
starts. After the brake is released, the output frequency increases according
to the set start function by par. 2.2.
t
Pa r4.12
Par 4.9
RUN
STOP
Output
frequency
DC-braking
current
Figure 9.12: DC braking time at start
4.15 E
XTERNAL BRAKE
: O
PEN DELAY
4.16 E
XTERNAL BRAKE
: O
PEN FREQUENCY LIMIT
4.17 E
XTERNAL BRAKE
: C
LOSE FREQUENCY LIMIT
4.18 E
XTERNAL BRAKE
: C
LOSE FREQUENCY LIMIT IN REVERSE
4.19 E
XTERNAL BRAKE
: O
PEN
/
CLOSE CURRENT LIMIT
External brake control is used for controlling a mechanical brake on the mo-
tor by digital / relay output by selecting value 17 for parameters P8.1, P8.2 or
P8.3. Brake is closed while relay is open and vice versa.
Opening brake conditions:
There are three different conditions for opening the brake, all must be true, if
used.
1. The Open frequency limit (P4.16) must be reached.