03.2004
Start-up
Siemens AG
6SE7087-2CX87-2DA0
SIMOVERT MASTERDRIVES
Unità di frenatura / Braking Unit
6-1
6 Start-up
Do not remove the front cover when voltage is applied to the
braking unit!
The control circuit is directly connected to the DC bus voltage!
Therefore the voltage limit switch may only be operated when the
braking unit is free of voltage.
The units have hazardous voltage levels up to 5 min. after the unit has
been powered-down due to the DC link capacitors.
Setting of the voltage limit switch:
In the case of the braking units, the response threshold can be
switched over.
This makes sense when a drive is operated from a 380 / 400 V or from
a 500 V or 660 V line, because during braking the DC bus voltage
increases only slightly. The voltage stress applied to motor insulation
will be reduced.
For 1 LA 1/5/6/8 type SIEMENS motors the voltage limit does not need
to be changed.
If the voltage limit switch is set to the lower limit, the braking power is
reduced (P~V
2
).
DANGER
NOTE