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.
 | 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 applications. |