Specifications

Dynamic Braking I Inhibit
Depending on the application, users may want to ramp their
motor down slowly (decelerate), while others may need to stop
more quickly. For rapid or frequent motor stopping capability,
most applications require regenerative drives. However, typical
Minarik drives contain inhibit circuitry. Inhibiting a drive causes
the output voltage to fall to zero or to a level determined by the
minimum speed trimpot.
Inhibiting occurs by closing a switch on most drives, and open-
ing a switch on others. Inhibiting single-quadrant drives simply
reduces the drive output to zero (or a calibrated minimum
voltage) which allows the motor and its load to coast. The drive
applies no braking torque, rather the system friction provides
the retarding forces. Inhibit bypasses the decel setting for
“coast-to-stop”. Opening the inhibit switch allows the motor to
accelerate smoothly to its set speed.
In four-quadrant (regenerative) drives, shorting the inhibit ter-
minals will regeneratively brake the motor. It bypasses both the
minimum speed and the deceleration settings for rapid braking
determined by the torque trimpot setting. Depending on the
drive wiring scheme, users can regeneratively brake a motor
(following the deceleration setting) to a stop, decelerate the
motor to minimum speed, or coast the motor to a stop (without
removing power) by shorting the INHIBIT-RUN terminals.
Minarik always recommends regenerative drives when
applications require fast, contactorless braking and revers-
ing. Even when reversing is not fast or frequent, regenera-
tive drives may still be the most long term economical solu-
tion. However, certain situations may call for another
method known as dynamic braking and reversing. This
method uses a relay or switch rated for motor current, and
a properly sized resistor. The brake resistor converts the
energy of the load into thermal energy in the brake resis-
tor. It is always recommended that the armature be dis-
connected only when the armature voltage is zero.
Reference
Recommended
Motor Brake Resistor Watts
Amps R
Brake
Less then 2 1Ω 1W
2A-3A 5Ω 5W
3A-5A 10Ω 10W
5A-10A 20Ω 20W
10A-17A 40Ω 50W
DYNAMIC BRAKING
INHIBIT
0 51
Call us toll free 1•800•MINARIK or download manuals at www.minarikdrives.com
K
REFERENCE