Parker AC890 Product Manual page 325

Functional Description
When enabled, the DYNAMIC BRAKING block monitors the internal dc link voltage every milli-second and sets the state of
the brake switch accordingly.
The dynamic braking block provides a control signal that is used by the SLEW RATE LIMIT block. This causes the setpoint to
be temporarily frozen whenever the dynamic brake is operating because the dc link voltage exceeds the internal comparison
level. This allows the stop rate to be automatically tuned to the characteristics of the load, motor, Drive and brake resistor.
The DYNAMIC BRAKING block operates even when the motor output is not enabled. This allows the block to continually
monitor the energy dumped into the braking resistor, and the energy dissipated across the brake switch. With this information
the Drive is able to deduce the loading on the brake resistor. Optional trips may be enabled should the switch or resistor be
loaded beyond its capabilities.
The "Brake Resistor" and "Brake Switch" trips are disabled by default. To enable these trips, refer to TRIPS STATUS, page D-
171. When using dynamic braking, the brake resistor information must be entered and these two trips enabled.
Refer also to Chapter 8: "Operating the Drive" - Dynamic Braking.
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Page 890SD Standalone Drive - Frames G, H & J