Product overview
Default operation mode 2 - Ext. brake resistor enabled (standalone brake chopper)
In this case the capacity of the DC links is fully
utilized. This operation mode must be selected and,
apart from the basic configuration of the brake
module, the internal brake resistors of the devices
in the DC link system should be deactivated, as
otherwise the thermal load in the control cabinet will
also increase. In order to reduce the thermal load
further, it is a good idea to mount an external brake
resistor on the brake module outside the control
cabinet.
2.8.3
Braking power diagnosis
The current continuous output of the brake resistor can be read via the IDNs P-0-0209 (int. brake resistor)
and P-0-0210 (ext. brake resistor). The unit is watts. Loads above 90% of the continuous output of the brake
resistor should be avoided. The IDNs can be read cyclically as process data.
The current impulse energy load of the brake resistor can be read via the IDNs P-0-0218 (int. brake resistor)
and P-0-0219 (ext. brake resistor). It is specified in % with one decimal place. Loads above 90% should be
avoided. The IDNs can be read cyclically as process data.
The maximum energy values since the last reset are stored in IDNs P-0-0220 (int. brake resistor) and
P-0-0221 (ext. brake resistor). The values can be reset by entering zero. Duty cycle corresponds to 100
seconds. The energy values are monitored at the specified intervals (100 ms, 1 s, 10 s, 20 s, 40 s and 100
s). The values for 100 s correspond to the continuous output. The maximum values should be approx. 10%
below the resistor limits (P-0-0207 or P-0-0208). If a current energy value exceeds the limit value of a brake
resistor, this brake resistor is not enabled. In a drive systems or in a configuration with active internal
chopper the other brake resistors have to absorb the energy. If this is not possible the DC link voltage will
continue to increase until an overvoltage error occurs, followed by disabling of the axes with "Torque off". It is
therefore important to ensure that adequate braking power is available in the systems, in order to avoid
uncontrolled movements of the axes. The diagnostics should cover the whole system. If not enough reserve
capacity is available, an external brake resistor with a higher output should be selected. If the performance
limit is still reached, several AX5021 may be used.
Note
Energy balance
The energy balance is affected positively whenever an axis requires energy and another
axis produces generative energy (braking energy). This rule should be observed in all appli-
cations.
AX5000 Brake module AX5021
10
Version: 1.3
