Parameters 291
Enables brake chopper control and selects the brake resistor
overload protection method (calculation or measurement).
Note:
Before enabling brake chopper control, ensure that
• a brake resistor is connected
• overvoltage control is switched off (parameter
• the supply voltage range (parameter
has been selected correctly.
Disabled
Brake chopper control disabled.
0
Enabled with
thermal model
Brake chopper control enabled with brake resistor protection
based on the thermal model. If you select this, you must also
specify the values needed by the model, ie. parameters
. See the resistor data sheet.
1
Enabled without
thermal model
Brake chopper control enabled without resistor overload
protection based on the thermal model. This setting can be
used, for example, if the resistor is equipped with a thermal
switch that is wired to open the main contactor of the drive if
the resistor overheats.
For more information, see chapter
Resistor
braking
in the
Hardware manual
.
2
Overvoltage peak
protection
Brake chopper control enabled in an overvoltage condition.
This setting is intended for situations where
• the braking chopper is not needed for runtime operation,
ie. to dissipate the inertial energy of the motor,
• the motor is able to store a considerable amount magnetic
energy in its windings, and
• the motor might, deliberately or inadvertently, be stopped
by coasting.
In such a situation, the motor would potentially discharge
enough magnetic energy towards the drive to cause damage.
To protect the drive, the brake chopper can be used with a
small resistor dimensioned merely to handle the magnetic
energy (not the inertial energy) of the motor.
With this setting, the brake chopper is activated only
whenever the DC voltage exceeds the overvoltage limit.
During normal use, the brake chopper is not operating.
3
Selects the source for quick brake chopper on/off control.
0 = Brake chopper IGBT pulses are cut off
1 = Normal brake chopper IGBT modulation allowed.
This parameter can be used to enable chopper operation only
when the supply is missing from a drive with a regenerative
supply unit.
Off
0.
0
On
1.
1
Source selection (see
). -
Defines the thermal time constant for the brake resistor
thermal model.
0 s
0…10000 s
Brake resistor thermal time constant, ie the rated time to
achieve 63% temperature.
1 = 1 s
No.
Name/Value
Description
Def/FbEq16
ACS580 FW.book Page 291 Wednesday, September 21, 2016 9:48 PM