Electrical installation
5
j
| BA 14.0190 - EN | 02/2007
30
Tip!
During operation according to Fig. 16 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. Install the rectifier in the terminal box. For motors with insulation class ”H”, the
rectifier must be installed in the control cabinet. The permissible ambient temperature
for the rectifier is -25
_
C to +70
_
C.
2. Compare the coil voltage of the stator to the DC voltage of the installed rectifier.
3. Select the suitable circuit diagram. Convert the values to deviating AC voltage, e.g.
with a 380V bridge rectifier,
– 380/400x205 = 195V
– Deviations up to 3% are permissible.
4. Motor and brake must be wired according to the requirements of the engagement
time.
