Rockwell Automation Flex/WebPak 3000 DC Drive DB Kit, 1.5 HP-150 HP-230V, 3HP-600 HP-460V w/o NEMA1 - Manual (Page 3)

Dynamic Braking Kits for FlexPak 3000 and WebPak 3000 Digital DC Drives 3
400 HP to 600 HP @ 460 VAC Drives
The 400 HP to 600 HP @ 460 VAC drives include a DC contactor and therefore only require the resistor
assembly (DB resistor). The wiring requirements are also different for these drives.
When the motor is running normally, the drive's normally-open M contacts are closed and the normally-closed
M contact is open. See figure 5. Note that when the drive is connected to the motor, the dynamic braking
resistor (dynamic braking grid) is disconnected.
Dynamic braking slows down a rotating DC motor and its load if the motor is disconnected from the drive. It is
typically initiated with a coast/DB stop command or a drive fault. When dynamic braking is initiated, the
normally-open M contacts open, the normally-closed M contact closes. The drive is then disconnected from the
motor and the dynamic braking resistor is connected across the armature; A1 and A2. The motor's rotating
armature now acts as a generator. The resulting current causes braking torque in the motor. While the motor is
decelerating, its energy is absorbed by the DB resistor. This causes this resistor's temperature to increase.
Dynamic braking decelerates the motor even with a drive failure, as long as motor field excitation is
maintained. This process is not controlled by software. The following table lists the contents of the 400 HP to
600 HP Dynamic Braking kits.
Description Quantity Reliance Part Number
Resistor Assembly:
400 HP to 600 HP @ 460 VAC
1
802272-53x
1
1.
See table 4 for the specific part number for your kit model number.
Enclosure:
400 HP to 600 HP @ 460 VAC 1 802272-52S
Hardware for Mounting:
5/16 -18×3/4 Carriage Bolt
5/16 -18 KEP Nut
Grommet
#10-32 T T Screw
#10 Flat Washer
Screw, Hex HD. M10×25mm
Flat Washer, M10
KEP Nut, M10
4
4
1
4
4
2
2
2 601745-2A
401599-11F
603100-A
601741-63C
601748-1C
419062-5HLM
419064-1SL
419063-201SL