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Gemini GT6 Hardware Installation Guide
Direction of Motor Rotation
The procedures above do not determine the direction of motor shaft rotation. To
find out which direction the shaft turns, you must power up your system and
command motion. If the shaft turns in the opposite direction than you desire,
exchange the motor leads connected to A+ and A– to reverse the direction of
rotation.
WARNING
Motor shaft rotation may be opposite than you expect. Do not connect a load to the
shaft until you first determine the direction of shaft rotation.
Autorun Mode, described in Chapter 2 Installation, provides a simple method of
determining motor shaft rotation. Autorun causes the shaft to rotate in the clock-
wise (positive) direction, if the motor wires are properly connected.
Setting Motor Current – Non-Compumotor Motors
To set motor current for a non-Compumotor motor, refer to the formulas below
that correspond to your motor (4-lead, 6-lead, 8-lead) and use the DMTIC com-
mand to set the motor’s current.
NOTE: Gemini drive specifications for output current are in amps peak. Most
motor current specifications are in amps rms. The DMTIC command uses amps
rms; do not use amps peak with the DMTIC command.
WARNING
Do not connect or disconnect the motor with the power on. Doing so will damage
the contacts of the motor connector and may cause personal injury.
4-Lead Motors
If you use a 4-lead motor, the manufacturer’s current specification will translate
directly to the value you should enter with the DMTIC command.
6-Lead Motors
Manufacturers generally use either a bipolar rating or a unipolar rating for motor
current in 6-lead motors.
Bipolar Rating: If the manufacturer specifies the motor current as a bipolar
rating, you can use the DMTIC command directly to set motor current—no
conversion is required.
Unipolar Rating: If the manufacturer specifies the motor current as a unipolar
rating:
•
Use the following formula to convert the unipolar current rating to the correct bipolar
rating:
Unipolar Current
∗
0.707 = Bipolar Current
•
Use the converted value and the DMTIC command to set the motor current.
