Siemens SINAMICS G150, Operating Instructions Manual

Page: 563 / 680

Functions, monitoring, and protective functions
9.3 Extended functions
Converter cabinet units
Operating Instructions, 07/2016, A5E03347396A
563
Example 2: Emergency brake
In the case of emergency braking, electrical and mechanical braking should be realized at
precisely the same time. This can be achieved if OFF3 is used as a tripping signal for
emergency braking:
p1219[0] = r0898.2 and p1275.00 = 1 (OFF3 to "apply brake immediately" and invert signal).
To prevent the converter working in opposition to the brake, the OFF3 ramp (p1135) should
be set to 0 seconds. Any prevailing regenerative energy must be converted into heat via a
braking resistor.
This is often used, for example, in calendar stacks, cutting tools, running gears, and presses.
Example 3: Service brake on crane drives
For cranes with manual control, it is important that the drive responds immediately when the
control lever is moved (master switch). To this end, the drive is powered up using the on
command (p0840) (the pulses are enabled). Speed setpoint (p1142) and speed controller
(p0856) are inhibited. The motor is magnetized. The magnetization time generally applicable
for three-phase motors (1 to 2 seconds) is, therefore, eliminated.
Now, only the brake opening time will delay the motor starting to rotate following activation of
the master switch. Movement of the master switch generates a "setpoint enable from the
control" (bit interconnected with p1142, p1229.2, p1224.0). The speed controller is enabled
immediately and the speed setpoint is enabled once the brake opening time (p1216) has
elapsed. When the master switch is in the zero position, the speed setpoint is inhibited and
the drive ramps down along the ramp-function generator's ramp-down ramp. The brake
closes once the standstill limit (p1226) is undershot. Once the brake closing time (p1217)
has elapsed, the speed controller is inhibited (the motor is no longer generating any force).
Extended braking control is used with the modifications described below.
Figure 9-19 Example: Service brake on a crane drive