Rockwell Automation 20D PowerFlex 700S AC Drives with Phase II Control Reference Manual User Manual
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Rockwell Automation Publication PFLEX-RM003E-EN-E - January 2011
Chapter 1 Detailed Drive Operation
Set parameter 414 [Brake/Bus Cnfg] for your configuration. The following is a
summary of possible settings for [Brake/Bus Cnfg]:
Parameter 415 [BusReg/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 [Brake/Bus Cnfg]. When using common DC bus
drives, adjustment of [BusReg/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.
Note:
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%:
Note:
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 x 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 [Brake/Bus 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
Desired Operation
[Brake/Bus Cnfg] Setting
Bit 3
Bit 2
Bit 1
Bit 0
External regeneration
0
0
0
0
Dynamic braking with internal resistor
0
0
0
1
Dynamic braking with external resistor
0
0
1
1
Bus regulation only
1
0
0
0
Bus regulation first, then dynamic braking with internal resistor
1
0
0
1
Dynamic braking with internal resistor first, then bus regulation
1
1
0
1
Bus regulation first, then dynamic braking with external resistor
1
0
1
1
Dynamic braking with external resistor first, then bus regulation
1
1
1
1
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
=
=