Overvoltage; Undervoltage; Foldback - Parker Compumotor TQ10 User Manual

Overvoltage

The TQ10 Drive monitors the voltage on the motor output terminals. If the voltage rises
above a threshold level, the drive will shut down power output to the motor, and will
illuminate red the bicolor LED labeled
the primary cause of an overvoltage fault.
This is a latched fault. To resume operations, cycle power; or, with the TQ10 Torque
drive, you can use the reset input.

Undervoltage

The TQ10 Drive monitors the voltage on its AC power input terminals. If the voltage falls
below 80VAC, the drive will shut down and activate its fault output. When you apply
power to the drive, the power-up event is indistinguishable from an undervoltage;
therefore, the undervoltage fault is not latched. Furthermore, an undervoltage fault will
unlatch any other faults that may be present at the time of the undervoltage.
There is no LED indicator for an undervoltage fault.

Foldback

A mechanical jam in a servo system can cause the motor to overheat. In contrast to a
stepper motor, which does not run hotter when jammed, a servo will apply full current (for
full torque) while it attempts to move as commanded. Usually, this current will be much
higher than the motor can withstand continuously. If it persists indefinitely, it may damage
the motor's windings.
To help protect the motor from overheating, the TQ10 has a current foldback circuit. If
high motor current persists for too long, the circuit can cause a fault, or reduce the current
to a lower level that decreases the rate of motor heating.
Three of the DIP switches on top of the drive allow you to set the maximum current the
drive will produce ("
no greater than three times the continuous current rating (Ics) of the motor used. This
setting is used by the foldback circuitry to help protect the motor.
Six of the DIP switches configure the foldback circuitry. Three of them set the time that
"high" current will be permitted before the foldback circuitry takes action. Settings range
from 1 to 10 seconds. One switch defines what constitutes "high" current. This is set
according to Ics. One switch will cause a latched fault to be generated when the selected
time at high current is exceeded, otherwise current is reduced ("folded back") to 40% of
the peak current limit setting. One switch allows foldback to be disabled entirely. See
Chapter 2—Installation and Chapter 4—Tuning (Tuning Procedure) for instructions on
setting the dip switches.
How Foldback Works
When actual current produced by the drive exceeds the threshold (relative to the peak
current limit) set with SW2-2, the foldback circuit illuminates the
green, and starts a timer. If the current remains above this threshold for longer than the
time set with the time-at-peak dipswitches, the foldback circuit activates, and the IN
FOLDBACK
configured, or B) reduce current to 40% of the peak current limit setting.
In case A (with
input is asserted. This fault condition will be indicated by a red
an active
comes on, depending on the load. When faulted, the motor current will be reduced
FAULT
to zero.
In case B (with
goes below the actual current, when the circuit will once again allow the full current
permitted by the peak current limit setting. While foldback is limiting the current, the
FOLDBACK
FAULT OUT
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PEAK CURRENT LIMIT
LED illuminates red. The circuit can generate: A) A latched fault, if so
), the fault will remain until power is cycled, or the
SW2-1 ON
signal. The
FAULT OUT IN FOLDBACK
), the current reduction will persist until the command input
SW2-1 OFF
LED will be red. When the command is reduced, the LED will go out. The
will not go active, since current foldback is not considered a fault.
. Excessive regeneration is
RED = OVERVOLTAGE
"). These switches should be set to a value
PEAK CURRENT
MOTOR FAULT
LED may go out when the
 Troubleshooting
LED
RESET
LED, and
MOTOR
IN
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