Rockwell Automation 20D PowerFlex 700S with Phase I Control Reference Manual User Manual
Page 22
22
Rockwell Automation Publication PFLEX-RM002D-EN-E - August 2013
Chapter 1
Detail Drive Configuration and Operation
Set the appropriate 414 [Bus/Brake Config] for your configuration. The
following is a summary of possible settings for [Bus/Brake Config]:
Parameter 415 [Bus Reg/Brake Ref ] sets the turn-on bus voltage threshold for
the bus regulator and the dynamic brake. Actual values are modified by the
configuration selected in [Bus/Brake Config]. When using common DC bus
drives, adjustment of [Bus Reg/Brake Ref ] allows a limited coordination of brake
operation with other drives. For example, when you have two common bus drives,
and one drive is larger than the other, set the larger drive to turn on at a lower
voltage than the smaller drive. In this manner, the smaller drive does not try to
dissipate all of the dynamic braking energy.
Actual bus voltage reference values are determined as a percentage of parameter
401 [Rated Volts] and the selected voltage class.
For example, with a 480V rated drive and [BusReg/Brake Ref ]=111%:
When the low voltage class is selected an additional multiplier of 1.2 is used. For
example parameter 401 [Rated Volts] = 400V AC, then parameter 401 * 1.2 =
480 VAC is used to determine the bus voltage reference:
In this case, if a drive has a selected low voltage class, but is run on a high voltage
class AC line, the dynamic brake will not automatically turn on.
Parameter 416 [Brake PulseWatts] sets the peak power reference for determining
the protection for an external brake resistor. Parameter 416 is active only if the
configuration is selected for an external brake (parameter 414 [Bus/Brake Cnfg]
bit 1 is set to 1). When the internal brake resistor is used then the protection is
determined from the drive-internal values. Normally this value is specified by the
resistor vendor as the energy rating (in Joules) or a 1 second power rating (in
Desired Operation
[Bus/Brake Config] Setting
External regeneration
0000
Dynamic braking with internal resistor
0001
Dynamic braking with external resistor
0011
Bus regulation only
1000
Bus regulation first, then dynamic braking with internal resistor
1001
Dynamic braking with internal resistor first, then bus regulation
1101
Bus regulation first, then dynamic braking with external resistor
1011
Dynamic braking with external resistor first, then bus regulation
1111
bus voltage reference
2
Par 401 [Rated Volts]
Par 415 [Bus Reg/Brake Ref]
Ч
Ч
100
------------------------------------------------------------------------------------------------------------------------------------------------- VDC
=
bus voltage reference
2
480
111
Ч
Ч
100
---------------------------------------
753.5 VDC
=
=
bus voltage reference
2
400
1.2
111
Ч
Ч
Ч
(
)
100
-----------------------------------------------------------
753.5 VDC
=
=