Rockwell Automation M3575TL Snubber Braking Kits, AC Drives, Enclosed - Manual (Page 19)

Enclosed Resistor Modules, Enclosed Transistor Modules 19
Troubleshooting
If a problem occurs on start-up or during normal operation, refer to the table below.
Problem Corrective Action
Resistor Braking Unit
Drive trips on overvoltage or
self-limits its decel rate – Ensure that the resistive load module is properly connected to the drive’s
braking control circuitry. This can be a chopper module internal to the drive or
an external braking kit.
– Verify the ohmic value of the resistive load (see table 1).
– Ensure that the resistive load is adequately sized for the application.
The cooling fan doesn’t turn on – Verify that temperature of load module exceeds 45 ° C.
– Verify that 115 VAC is present for fan voltage.
Temp alarm contact is open
indicating an overtemp fault is
present – If the fault output is open and the chassis is hot, allow the unit to cool and
recheck the fault output; it should return to its normally closed state.
– If the fault output is open and the chassis is cool, replace the unit.
Temp alarm contact does not open
on overtemp condition – If the fault output remains closed and the chassis temperature exceeds 85 ° C,
disconnect the load module and allow the unit to cool. Once the chassis has
cooled, replace the unit.
Transistor Braking Unit
Green DC Bus Power LED does not
come on – Ensure proper DC bus voltage at the unit’s input terminals. If the proper bus
voltage is not present, ensure that the voltage rating of the unit matches the
drive.
Red Active Braking LED stays on or
flashes during motoring operation – Ensure that the voltage rating of the unit matches the drive.
– If line voltage is abnormally high or low, the unit may require special calibration
adjustments. Contact Reliance for assistance.
Fault output on unit is open
indicating a fault is present – If the fault output is open and the chassis is hot, allow the unit to cool and
recheck the fault output; it should return to its normally closed state.
– If the fault output is open and the chassis is cool, check the resistor path to
make sure it is not open.
– Remove DC bus power from the unit and then restore power. If the fault output
remains open, replace the unit.
Drive trips on overvoltage or
self-limits its decel rate – Ensure that the green DC Bus Power LED is on.
– Ensure that the proper resistive load value is connected to the unit and that the
maximum current rating is not exceeded.
– Ensure the unit is not exceeding the current rating. The braking IGBT will shut
down on overcurrent conditions. Check for a fault output.