Siemens 420 manual On / OFF2, Motor holding brake after OFF2

3 Functions Issue 07/04

The motor holding brake is either closed using OFF1 / OFF3 or OFF2. For OFF1 / OFF3, when the minimum frequency P1080 is reached, the motor is operated at this frequency until the brake has been applied (closing times of brakes lie between 15 ms and 300 ms). The actual time is specified using parameter P1217 "Holding time after ramp down" (refer to Fig. 3-48). If, on the other hand, an OFF2 command has been output, then independent of the drive state, the status signal r0052 bit 12 "Motor holding brake active" is reset. This means that the brake immediately closes after OFF2 (refer to Fig. 3-49).

ON / OFF2:
OFF2
Inactive
Active	t
ON
OFF1/OFF3	t
Motor excitation
finished	t
r0056 Bit04
f	P0346
fmin
(P1080)
	t
	P1216
r0052.C
1
0	t

Fig. 3-49 Motor holding brake after OFF2

The mechanical brake is controlled using the status signal r0052 bit 12 "Motor holding brake active" of the brake control. This signal can be output as follows:

Via digital output

The status signal is output via the digital output. In this case, the internal MICROMASTER relay (if the specification is sufficient) or also an external contactor or relay can be used to control the brake.

Via status signal using the serial interface (USS or PROFIBUS)

The master must process the status signal. The signal must be connected to the digital output of the master to which the contactor / relay for the motor holding brake is connected.

MICROMASTER 420	Operating Instructions
120	6SE6400-5AA00-0BP0