Siemens SINAMICS G120 CU230P-2, Operating Instructions Manual, Page: 270 / 346

Functions
7.9 Application-specific functions
Frequency inverters with Control Units CU230P-2 HVAC, CU230P-2 DP, CU230P-2 CAN
268
Operating Instructions, 01/2011, FW 4.4, A5E02430659B AD
General properties of the bypass function
● y
● Contactors K1 and K2 must be mutually interlocked so that they cannot close at the same
time.
Shutdown behavior in bypass operation
●
If the motor is in the bypass mode, it cannot be shutdown with OFF 1. The motor coasts
down after an OFF2 or OFF3.
● If the motor is running in the bypass mode and the inverter is disconnected from the line
supply, then also the bypass contactor does not receive control signals from the inverter
and the motor coasts down. If the motor is to continue running once the inverter is
switched off, the signal for the bypass contactor must therefore come from the higher-
level control.
Temperature monitoring and overload protection in the bypass mode
●
If the motor is running in the bypass mode, while the inverter is in the "ready and bypass"
state (r899.0 = 1 and r0046.25 = 1), then the motor temperature monitoring via the
temperature sensor is active.
● If the motor is running in the bypass mode, while the inverter is in the "ready and bypass"
state (r899.0 = 1 and r0046.25 = 1), then the overload protection for the motor must be
realized on the plant or system side.
Parameters for setting the bypass function
Parameter Description
p1260 Bypass configuration
Activating the bypass function
r1261 Bypass control/status word
Control and feedback signals for the bypass function.
p1262 Bypass dead time
Changeover time for contactors. This should be longer than the motor's
demagnetizing time!
p1263 Debypass delay time
Delay time for switching back to inverter operation.
p1264 Bypass delay time
Delay time for switching to bypass operation.
p1265 Bypass speed threshold
Speed threshold for switching to bypass operation.
p1266 Bypass control command
Signal source for switching to bypass operation.
p1267 Bypass changeover source configuration
Switch to bypass operation using speed threshold or control signal.
p1269 Bypass switch feedback
Signal source for contactor feedback for the bypass mode.
p1274 Bypass switch monitoring time
Monitoring time setting for bypass contactors.
For more details about parameters, please refer to the List Manual.