ABB ACS880 Series Firmware Manual page 308

308 Parameters
No. Name/Value
Overvoltage peak
protection
43.07 Brake chopper run
enable
Off
On
Other [bit]
43.08 Brake resistor
thermal tc
0 ... 10000 s
43.09 Brake resistor
Pmax cont
0.00 ...
10000.00 kW
43.10 Brake resistance
0.0 ... 1000.0 ohm
43.11 Brake resistor fault
limit
0 ... 150%
43.12 Brake resistor
warning limit
0 ... 150%
Description
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 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.
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.
Selects the source for quick brake chopper on/off control.
0 = Brake chopper IGBT pulses are cut off
1 = Normal brake chopper IGBT modulation.
This parameter can be used to program the chopper control
to function only when the supply is missing from a drive with a
regenerative supply unit.
0.
1.
Source selection (see Terms and abbreviations
Defines the thermal time constant of the brake resistor for
overload protection.
Brake resistor thermal time constant.
Defines the maximum continuous braking power of the
resistor (in kW) which will raise the resistor temperature to the
maximum allowed value. The value is used in the overload
protection.
Maximum continuous braking power.
Defines the resistance value of the brake resistor. The value
is used for brake chopper protection.
Brake resistor resistance value.
Selects the fault limit for the brake resistor temperature
protection function. When the limit is exceeded, the drive trips
on fault 7183 BR excess
The value is given in percent of the temperature the resistor
reaches when loaded with the power defined by parameter
43.09 Brake resistor Pmax
Brake resistor temperature fault limit.
Selects the warning limit for the brake resistor temperature
protection function. When the limit is exceeded, the drive
generates a A793 BR excess temperature
The value is given in percent of the temperature the resistor
reaches when loaded with the power defined by parameter
43.09 Brake resistor Pmax
Brake resistor temperature warning limit.
on page 112). -
temperature.
cont.
warning.
cont.
Def/FbEq16
3
On
0
1
0 s
1 = 1 s
0.00 kW
1 = 1 kW
0.0 ohm
1 = 1 ohm
105%
1 = 1%
95%
1 = 1%