Siemens 420 manual 12.3 OFF/braking functions, OFF1

Issue 07/04 3 Functions

3.12.3OFF/braking functions

Parameter range:	P1121, P1135, P2167, P2168
	P0840 – P0849
	r0052 bit 02
Warnings	-
Faults	-
Function chart number:	-

The drive inverter and the user must respond to an extremely wide range of situations and stop the drive. In this case, both requirements relating to operations as well as drive inverter protective functions (e.g. electrical and thermal overload) and man-machine protective functions have to be taken into account. As a result of the different OFF/braking functions (OFF1, OFF2, OFF3) MICROMASTER can flexibly respond to the requirements mentioned above.

OFF1

The OFF1 command is closely coupled to the ON command. When the ON command is withdrawn, then OFF1 is directly activated. The drive is braked by OFF1 with the ramp-down time P1121. If the output frequency falls below the parameter value P2167 and if the time in P2168 has expired, then the inverter pulses are cancelled.

fact

	P1082
	fmax	OFF1
	P2167
		t
		P2168
r0052 Bit02		tdown,OFF1
		P1121
Operation			= P1121⋅	f 2
	Pulse	tdown,OFF1
				P1082
cancellation		t
Fig. 3-44	OFF1

NOTE

OFF1 can be entered using a wide range of command sources via BICO parameter P0840 (BI: ON/OFF1) and P0842 (BI: ON/OFF1 with reversing).

BICO parameter P0840 is pre-assigned by defining the command source using P0700.

The ON and the following OFF1 command must have the same source.

If the ON/OFF1 command is set for more than one digital input, then only the digital input that was last set, is valid, e.g. DIN3 is active.

OFF1 can be combined with DC current braking or compound braking.

When the motor holding brake MHB (P1215) is activated, for an OFF1, P2167 and P2168 are not taken into account.

MICROMASTER 420	Operating Instructions
6SE6400-5AA00-0BP0	115