Installing Additional Drive Units - ABB OmniCore V250XT Type B Product Manual

3 Installation and commissioning

3.7.4 Installing additional drive units

3.7.4 Installing additional drive units
General
The following sections describe the standard installation of additional drive units.
For more complex configurations please contact ABB.
For information about additional axes, see Application manual - Additional axes
for OmniCore.
Additional axis brake snubber
Each time a motor brake is engaged, there will be an inductive kickback, that is a
rapid change in voltage across the brake terminals. This is a result of the inherent
inductance of the brake circuit.
For robots, this inductive kickback is handled by individual snubbers at each motor
and at the brake release board in the robot.
ABB products such as Track Motion, Positioners, Motor Units, Gear Units are
equipped with integrated brake snubbers.
When integrating a motor not delivered by ABB, it is of great importance that the
motor has a snubber fitted across the brake terminals, at the motor. Failure to do
so will void warranty and may result in drive unit failure.
The maximum allowed voltage across the brake terminals is 65V.
The following illustration shows possible implementations of snubber circuits:
1)
2)
xx2200001374
1
2
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Note
Make sure the robot software is configured to reflect the drive functions installed.
24V_BRAKE
0V_BRAKE
24V_BRAKE
0V_BRAKE
The resistor in this snubber circuit may be omitted. The diode should be
dimensioned for the same current as the relay coil, and a voltage of at
least twice the brake release voltage.
The varistor should be dimensioned for the same energy as the brake
coil.
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Snubber Motor brake
R
D
Snubber Motor brake
VAR
Product manual - OmniCore V250XT Type B
3HAC087112-001 Revision: A