Siemens 420 manual Sequence ➀, DC braking after OFF1 / OFF3

Issue 07/04 3 Functions

The DC brake can therefore support a braking operation from approx. < 10 Hz or prevents / minimizes the increase in the DC link voltage for regenerative braking. This is realized because energy is directly absorbed in the motor. The essential advantage and the main application of the DC brake is the fact that a holding torque can be generated at standstill (0 Hz). For instance, this is important for applications where after positioning, any motion in the mechanical system / product itself can result in waste.

DC braking is especially used for: Centrifuges

Saws

Grinding machines Conveyor belts

Sequence ➀

1.Enabled using P1233

2.DC braking is activated with the OFF1 or OFF3 command (refer to Fig. 3-51)

3.The inverter pulses are inhibited for the duration of the de-magnetizing time P0347.

4.The required braking current P1233 is then impressed for the selected braking time P1232. The status is displayed using signal r0053 bit 00.

The inverter pulses are inhibited after the braking time has expired.

1
ON
OFF1/OFF3	t
	P0347
OFF2
	t
 f	OFF2
	DC braking
	t

DC braking active

r0053 1 Bit00 0

t

P1233

Fig. 3-51 DC braking after OFF1 / OFF3

MICROMASTER 420	Operating Instructions
6SE6400-5AA00-0BP0	123