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Rockwell Automation Publication 20P-TG001C-EN-P - February 2018
Chapter 2
Component Test Procedures
Thermistors and Thermal
Switches
An external, user-supplied thermistor (PTC) or thermal switch can detect
motor overheating. The PTC or thermal switch must be connected to
terminals 78 and 79 on the control power terminal block on the pulse
transformer circuit board. See
for terminal block
location.
A “Motor Over Temp” fault (F16) or alarm typically identifies an overheating
motor.
• See Fault Descriptions in the PowerFlex Digital DC Drive User Manual,
publication
for details.
on page
for a circuit diagram.
Verify that the PTC or thermal switch is correctly configured:
• If a thermal switch is used, a 1 kΩ resistor must be placed in series
between the switch and either terminal 78 or 79.
• If a thermistor (PTC) or thermal switch is not installed, a 1 kΩ resistor
must be connected between terminals 78 and 79.
A bimetal thermostat that is installed directly on the heat sink monitors the
drive heat sink temperature. When the heat sink temperature is too high, a
“Heatsink OvrTemp” fault (F8) occurs.
• See Fault Descriptions in the PowerFlex Digital DC Drive User Manual,
publication
for details.
on page
for a circuit diagram.
During normal operation, 1.6V DC is present between terminal 78 and drive
common. When an open circuit exists between terminals 78 and 79, 24V DC
will be present at terminal 78 to drive common. If the 24V is missing, the pulse
transformer board can need replacement.
Relay Outputs
Terminals 35 and 36 and 75 and 76 are N.O. relay outputs. The relay output
between terminals 35 and 36 is configured with parameter 1392 [Relay Out 1
Sel]. The relay output between terminals 75 and 76 is configured with
parameter 629 [Relay Out 2 Sel]. See Using Contactors in the PowerFlex
Digital DC Drive User Manual, publication
information.
The “Main Contactor” fault (F10) indicates a problem that is related to a
contactor used with the drive. See Fault Descriptions in the PowerFlex Digital
DC Drive User Manual, publication
for details.