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Parameters 327
Enabled without
thermal model
Brake chopper control enabled without resistor overload
protection based on a thermal model. This setting can be
used, for example, if the resistor is equipped with a thermal
circuit breaker that is wired to stop the drive if the resistor
overheats.
Before using this setting, ensure that overvoltage control is
switched off (parameter
)
2
Overvoltage peak
protection
Brake chopper starts to conduct at 100% pulse width
whenever
• the DC voltage exceeds the overvoltage fault limit (a
hysteresis applies), and
• the drive is not modulating (for example, during a coast
stop).
The thermal model-based resistor overload protection is not
active.
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 of
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.
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
Defines the maximum continuous load of the brake resistor
which will eventually raise the resistor temperature to the
maximum allowed value (= continuous heat dissipation
capacity of the resistor in kW) but not above it. The value is
used in the resistor overload protection based on the thermal
model. See parameter
, and the
brake resistor data sheet.
0.00 kW
0.00 …
10000.00 kW
Maximum continuous load of the brake resistor.
1 = 1 kW
Defines the resistance value of the brake resistor. The value is
used for the brake chopper protection based on the thermal
model. See parameter
0.0 ohm
0.0 … 1000.0 ohm
Brake resistor resistance value.
1 = 1 ohm
No.
Name/Value
Description
Def
/
FbEq16
Содержание ACS880-x04
Страница 1: ... ABB INDUSTRIAL DRIVES ACS880 primary control program Firmware manual ...
Страница 4: ......
Страница 18: ...18 Using the control panel ...
Страница 24: ...24 Control locations and operating modes ...
Страница 111: ...Application macros 111 Fieldbus control macro This application macro is not supported by the current firmware version ...
Страница 112: ...112 Application macros ...
Страница 496: ...496 Additional parameter data ...
Страница 544: ...544 Fault tracing ...
Страница 602: ...602 Control chain diagrams ...