Rockwell Automation 1336_S_F_T Allen-Bradley Dynamic Braking - Manual (Page 2)

Heavy Duty Dynamic Braking 2
1336-5.64 — July, 2005
What This Option Provides The Heavy Duty Dynamic Braking Option provides a self contained NEMA
Type 1 enclosed assembly that is wired to a 1336 AC Drive. Dynamic
braking can increase the braking torque capability of a drive up to 100%.
Where This Option Is Used B003-B250 and C003-C250 1336 Drives
B003-B250 1336VT Drives
AQF05-A010, BRF05-B250 and C007-C250 1336 PLUS and 1336 FORCE
Drives
What These Instructions
Contain These instructions describe Dynamic Brake Module operation and explain
how to calculate the data needed to correctly select, configure and install a
Heavy Duty Dynamic Brake Module. By completing How to Select a
Dynamic Brake Module first, you will be able to determine:
1. Whether or not Heavy Duty Dynamic Braking is required for your
application.
2. If Heavy Duty Dynamic Braking is required, the rating and quantity of
brakes required.
How Dynamic Braking Works When an induction motor’s rotor is turning slower than the synchronous
speed set by the drive’s output power, the motor is transforming electrical
energy obtained from the drive into mechanical energy available at the drive
shaft of the motor. This process is referred to as motoring. When the rotor
is turning faster than the synchronous speed set by the drive’s output power,
the motor is transforming mechanical energy available at the drive shaft of
the motor into electrical energy that can be transferred back into the utility
grid. This process is referred to as regeneration.
Most AC PWM drives convert AC power from the fixed frequency utility
grid into DC power by means of a diode rectifier bridge or controlled SCR
bridge before it is inverted into variable frequency AC power. Diode and
SCR bridges are cost effective, but can only handle power in the motoring
direction. Therefore, if the motor is regenerating, the bridge cannot conduct
the necessary negative DC current, the DC bus voltage will increase and
cause a Bus Overvoltage trip at the drive.
Catalog Number Description
1336 — MOD — K B 005
1336/1336VT/1336 PLUS/1336 FORCE
Heavy Duty Dynamic Braking
Voltage Rating
A = 230V AC
B = 380/415/460V AC
C = 500/575V AC
Brake Kit Code
005 = Drive Ratings 003-005/F05-F50
010 = Drive Ratings 007-010
050 = Drive Ratings 040-060