
10
Malfunctions
Brake malfunctions
Operating Instructions – EDR..71 – 315, EDRN63 – 315
219
10.3
Brake malfunctions
Fault
Possible cause
Measure
Brake does not re-
lease
Incorrect voltage on brake control
unit
Apply the correct voltage; brake voltage specified
on the nameplate
Brake control unit failed
Install a new brake control, check resistance and
insulation of the brake coils (see "Resistance"
chapter for resistance values)
Check switchgear, replace if necessary
Max. permitted working air gap ex-
ceeded because brake lining worn
down
Measure and set working air gap.
If the brake disk is too thin, replace the brake disk.
Voltage drop along supply cable >
10%
Provide correct connection voltage: brake voltage
specifications on the nameplate. Check the cable
cross section of the brake cable; increase cross
section if necessary
Inadequate cooling, brake over-
heats
Provide for cooling air supply or clear cooling air
passages, check air filter, clean or replace if ne-
cessary.
Brake coil has interturn fault or
short circuit to frame
Check resistance and insulation of the brake coils
(see "Resistance" chapter for resistance values);
Replace complete brake and brake control (spe-
cialist workshop),
Check switchgear, replace if necessary
Rectifier defective
Replace rectifier and brake coil; it may be more
economical to replace the complete brake
Brake does not
brake
Working air gap not correct
Measure and set working air gap.
If the brake disk is too thin, replace the brake disk.
Brake lining worn down
Replace entire brake disk.
Incorrect braking torque
Check the project planning and change the brak-
ing torque if needed; see chapter "Technical Data"
> "Work done, working air gap, braking torques"
•
by changing the type and number of brake
springs.
•
by selecting a different brake
Working air gap so large that set-
ting nuts for the manual brake re-
lease come into contact
Set the working air gap.
Manual brake release device not
set correctly
Set the adjusting nuts for the manual brake re-
lease correctly
Brake locked by manual brake re-
lease HF
Loosen the set screw, remove if needed.
Brake is applied
with time lag
Brake is switched only on AC
voltage side
Switch both, the DC and AC voltage sides; ob-
serve wiring diagram
25896334/EN – 06/2019