INSTALLATION
9
FAULT / RESET
(INPUT/OUTPUT)
Terminal 7 is the Fault/Reset Terminal. This serves both as an output, to indicate when
a fault has occurred; and as an input, to reset the drive.
The CN0165 has protection circuitry to shut down the drive when potentially damaging
conditions exist. The state of the protection circuitry is available on the Fault/Reset
Terminal. The Fault LED (light emitting diode) provides visual indication of the fault
condition.
The Fault Output latches low and the LED stays on for either of the following fault
conditions:
•
A short circuit of the motor windings (or motor lead wiring)
•
Overheating: temperature of CN0165 exceeds 70°C
A short circuit reset is distinguished from an overheating reset by observing the case
temperature of the CN0165. A short-circuit reset will shut down the drive before it
reaches a high temperature. If the case temperature is low immediately after a reset
occurs, the cause is a short circuit.
Do not continue to operate the CN0165 if it is resetting due to overheating. Heat sinking
must be provided to prevent the drive from repeatedly entering thermal shutdown.
The Fault Output goes low (LED on), but does not latch, if the power supply voltage
drops below 18 volts DC. When no fault condition exists, the Fault Output is pulled up
to 12 volts DC by an internal 470 ohm resistor and the LED is turned off. The Fault
Output is capable of sinking up to 20 milliamps of current.
While the Fault Output is low, the internal counters reset to microstep zero and the
phase outputs are held low. The CN0165 ceases all switching activity and the motor
phase current goes to zero. A latched fault condition is cleared by a Reset (take
Terminal 7 to ground) or by recycling the power supply to the drive (power off, power
on).
Terminal 7 also functions as a Reset input. By taking the Fault/Reset Terminal to
ground, the motor phase currents are shut off and the internal counters are reset. When
Terminal 7 is released from ground the motor is located at microstep zero. A current of
20 milliamps will flow from the Fault/Reset Terminal when it is shorted to ground.
THE PROTECTION PROVIDED BY THE INTERNAL TEMPERATURE
SENSOR OF THE CN0165 IS NOT A SUBSTITUTE FOR ADEQUATE
HEAT SINKING. REPEATEDLY TRIPPING THE FAULT OUTPUT BY
ALLOWING THE DRIVE TO OVERHEAT CAUSES THERMAL STRESS
THAT WILL EVENTUALLY LEAD TO FAILURE OF THE DRIVE.
Summary of Contents for CN0165
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