Electrical installation5
j | BA 14.0168 | 10/2013
38
Tip!
During operation according to Fig. 18 the air gap is only monitored when no voltage is applied
to the brake. This makes sense because it is possible that when the current flows only one
side of the armature plate is attracted at first. This misalignment may cause a simulation of the
maximum air gap and the actuation of the microswitch. If there is no closed contact in parallel
to the microswitch contact, motor and brake will be switched off. The microswitch contact is
closed again when the armature plate is completely released - the release is repeated again -
because of the small difference-contact travel of the microswitch.
To avoid this misinterpretation of the microswitch signal, the signal should only be processed
when no voltage is applied to the brake.
1. Mount the rectifier in the terminal box. With motors of the insulation class ”H”, mount
the rectifier in the control cabinet. Permissible ambient temperature for the rectifier
-25 _C to +70 _C.
2. Compare the coil voltage of the stator to the DC voltage of the rectifier installed.
Conversion of supply voltage to DC voltage:
– Bridge rectifier: U
DC
=U
AC
•0.9
– Half-wave rectifier: U
DC
=U
AC
•0.45
– Permissible deviation of U
coil
and U
DC
up to ±10%.
3. Select suitable circuit diagram ( 35).
Note!
Selection of the rectifier at voltages ≥ 460 V AC catalogue ”Electronic
switchgear and accessories” Chapter spark suppressors and rectifiers.
4. Motor and brake must be wired according to the requirements of the engagement
time.
5.2 Bridge/half-wave rectifiers (option)
BEG-561- -
Bridge/half-wave rectifiers are used for the supply of electromagnetic spring-applied DC
brakes which have been released for operation with such rectifiers. Any other use is only
permitted with the explicit written approval of INTORQ.
Once a set overexcitation time has elapsed, the bridge/half-wave rectifiers switch over from
bridge rectification to half-wave rectification.
Terminals 3 and 4 are located in the DC circuit of the brake. The induction voltage peak for
DC switching (see ”DC switching - fast engagement” circuit diagram) is limited by an
integrated overvoltage protection at terminals 5 and 6.
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