Appendix A Dynamic Brake Hardware - Baldor ID15J1F50-ER Installation And Operating Manual

Appendix A
Dynamic Brake Hardware
Dynamic Braking (DB) Hardware
Whenever a motor is abruptly stopped or forced to slow down quicker than if
allowed to coast to a stop, the motor becomes a generator. This energy
appears on the DC Bus and must be dissipated using dynamic braking
hardware. Dynamic braking (DB) hardware is a resistive load. Table A-1
provides a matrix of DB turn ON and turn OFF voltages.
Parameter Description
Nominal Voltage
Overvoltage Fault
(Voltage exceeded)
DB ON Voltage
DB Upper Tolerance Peak
DB OFF Voltage
Braking torque and time should not exceed the available drive braking torque
and time rating. The drive braking torque is limited to the available peak
current and peak current time rating of the control. If the peak current or peak
current time limit is exceeded during braking, the control may trip on an over
voltage or a regen power fault.
Selection Procedure
1.
2.
3.
Hoisting Load Calculations
1.
2.
MN715J
Calculate the watts to be dissipated using the following formulas for the
appropriate load type.
Identify the control model number and determine which braking
hardware is required based on the model number suffix: ER.
Select appropriate braking hardware from Baldor 501 Catalog or Table
A-2.
Calculate braking duty cycle:
Lowering Time
Duty Cycle +
Total Cycle Time
Calculate braking watts to be dissipated in dynamic braking resistors:
duty cycle
Watts +
where: lbs = weight of load
FPM = Feet Per Minute
efficiency = mechanical efficiency
i.e., 95% = 0.95
Table A-1
Control Input Voltage
115VAC
400VDC
381VDC
388VDC
375VDC
lbs FPM efficiency
44
Dynamic Brake Hardware A-1
230VAC 460VAC
400VDC 800VDC
381VDC 762VDC
388VDC 776VDC
375VDC 750VDC