Baumuller BUM64A, Manual

Page: 113 / 120

Safety relay
Manual Single Power Unit BUM64S/A/F
Document no.: 5.01056.03
113
of 118
E
The diagram shows exemplary the usage and cabling of a Baumüller converter of the series
BUM 6, BUS 6 or BKH of a machine tool, at which the safe taking of work pieces at opened bar-
rier according to category 4 (EN 954-1) is possible.
Figure 32: Example for an application for safe stop according to category 4 (EN 954-1)
The switching-off of the electrical drive motor takes place three-ported.
n The contactor K1 with three NC contacts short-circuits the current to the motor in the release
state in all poles (closed-circuit current principle), so that no electrical energy of the converter
arrives at the motor. S2 (NC contact) and S3 (NO contact) effectuate K1. Only if S2 and S3
display a closed barrier (and therewith a safe condition) K1 starts up and the short-circuit in
the motor line is reset. The status signal contact of K1 (NO contact) to the monitoring circuit
is constructed with mechanical with the NC contacts connected contacts. The selection of the
contactor takes place after its limiting short-time current load capability (10 ms). This must be
bigger than the nominal current of the used semiconductor fuses at the mains input of the
converter.
n S1 (NC contact) has hardware effects on the safety relay of the converter. Only then if S1
displays a closed barrier (and therewith a safe condition) voltage is applied to the safety relay
input (X68: 3) and therewith makes a torque generation at the shaft of the motor. The NO con-
tact of S1 is connected with the monitoring circuit.
n S3 (NO contact) has hardware effects on the impulse release input of the converter (X26: 14).
Only if S3 displays a closed barrier (and therewith a safe condition) voltage is applied to the
impulse release input of the converter.
n The monitoring circuit, a fail-safe monitoring control of the category 4 (EN 954-1), checks on
its own the directly connected switch contacts of the position switches S1 (NO contact), S2