Trust TA333 - 1.15 Motor Connections; Motor Connection Types

Trust Automation, Inc. TA333 High Power Linear Servo Amplifier
10-Apr-09 Page 14 of 38
P
D
= 15A (72V-10V)
= 930W *
* This is over the 600W continuous dissipation rating so there will be a short time limit applied based on
the SOA chart before FAULT is generated. See SOA chart. (See section 2.4)
Dual-brushed example:
Assume a pair of 48V supplies and a motor that is expected at any one time to require 10A peak load at
a phase voltage requirement of 12V according to calculations. Because the motor(s) are referenced to
the power supply ground, the calculations are based on the full motor voltage.
P
D
= I
motor
(V
supply
– V
motor
)
I
motor
= 10A [calculated based on required torque]
V
motor
= 12V [calculated based on velocity]
V
supply
= 48V [one of two 48V supplies]
P
D
= 10A (48V-12V)
= 360W *
* This is under the 600W continuous dissipation rating, but the current is over the 6A continuous, so
there will be a time limit applied based on the SOA chart before FAULT is generated (10A @ 30c =
~3.2sec before fault). (See SOA chart, section 2.4)
1.15 Motor Connections
The TA333 motor connections are made at connector J5. The available output voltage is limited to the
supply voltage, less approximately 8V off each rail. With ±48V supplies, there will be 80V available
across the motor before the output starts to clip. Pin 1 on J5 is earth ground and is electrically isolated
from all power connections. By physically connecting the TA333 chassis and the motor chassis to an
earth ground, immunity from external noise sources is increased.
Note: When designing a system E-stop, never cut the motor leads. This will result in a runaway
condition and may damage the TA333. Always cut the incoming DC supply (crowbar with a low value
resistor) to the TA333 to produce a rapid stop.
Brushless Motor
The phase outputs A, B and C correlate to most motor callouts as U, V and W or in some cases R, S
and T. (See application examples 5.1, 5.2, and 5.3)
Brushed Motor in Bridged Mode
To drive a single brushed motor in bridge mode, connect the motor “+” lead to the A phase output and
the motor “–” lead to the C phase output. This configuration allows the full bipolar supply voltage to be
driven across the motor in any direction of rotation. The motor can be a traditional brushed or voice coil
type. (See application example 5.4)