INTORQ BFK458 - Troubleshooting and Fault Elimination; Brake Cannot Be Released, Air Gap Is Not Zero; Rectifier Defective or Incorrect

Troubleshooting and fault elimination
INTORQ | BA 14.0168 | 11/2018 71
9 Troubleshooting and fault elimination
If any malfunctions should occur during operations, please check for possible causes based on the follow-
ing table. If the fault cannot be fixed or eliminated by one of the listed steps, please contact customer ser-
vice.
Fault Cause Remedy
Brake cannot be re-
leased, air gap is not
zero
Coil interruption
¾
Measure coil resistance using a multimeter:
- Compare the measured resistance with the nominal resist-
ance. Refer to Rated data for coil powers
,Page26 for the val-
ues.
- If resistance is too high, replace the complete spring-applied
brake.
Coil has contact to earth or
between windings
¾
Measure coil resistance using a multimeter:
- Compare the measured resistance with the nominal resist-
ance. Refer to Rated data for coil powers
,Page26 for the val-
ues. If resistance is too low, replace the complete stator.
¾
Check the coil for short to ground using a multimeter:
- If there is a short to ground, replace the complete spring-
applied brake.
¾
Check the brake voltage (refer to section on defective recti-
fier, voltage too low).
Wiring defective or wrong
Check the wiring and correct.
¾
Check cable for continuity using a multimeter
- Replace the defective cable.
Rectifier defective or incor-
rect
¾
Measure rectifier DC voltage using a multimeter.
¾
If DC voltage is zero:
¾
Check AC rectifier voltage.
¾
If AC voltage is zero:
- Switch on the voltage
- Check the fuse
- Check the wiring
¾
If AC voltage is okay:
- Check the rectifier
- Replace the defective rectifier
¾
Check coil for inter-turn fault or short circuit to ground.
¾
If the rectifier defect occurs again, replace the entire spring-
applied brake, even if you cannot find any fault between
turns or short circuit to ground. The error may only occur on
warming up.