Rockwell Automation 1336R REGEN LINE REG - Manual (Page 59)

Regenerative Brake Operation 3–7
Regenerative Brake
Sizing Additional Requirements
In addition to satisfying the peak current requirements, the
application must satisfy the duty cycle limitations of the 1336
REGEN Package. After operating in the overload region, the 1336
REGEN Package must operate at or below rated current for some
period of time before it can be overloaded again. The overload
region is useful for applications requiring intermittent
regeneration, or those that alternate between regeneration and
motoring.
One regeneration profile that is cyclic in nature is shown below.
In this case, the motor holds back on an overhauling load (or
regenerates) for
t seconds. After t seconds, the motor provides
positive torque for T–t seconds. The total cycle time is represented
by T , and the duty cycle ( DC ) is
DC = t %
——
T
The table below summarizes the maximum regeneration time and
duty cycle that the 1336 REGEN Package can handle with various
peak currents for a given overhauling load. As long as
I
PK
is less
than 150% and the conditions in the table are satisfied, the 1336
REGEN Package will not trip on overload.
Other applications require deceleration of the load in a cyclic
pattern as shown below.
In this case, the required braking torque drops with speed. The
deceleration time is represented by
t , and the total cycle time is
represented by T .
Peak Regenerative Current
(I
PK
)
Maximum on Time
(t) Maximum Duty Cycle
(DC)
150% 1 Minute 70%
140% 1 Minute, 17 Seconds 75%
130% 1 Minute, 48 Seconds 81%
120% 3 Minutes 88%
110% 9 Minutes 96%
time
t
T
t
T
time