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Functions, monitoring and protective functions
9.4 Extended functions
The bypass function is automatically restarted by the restart process. To accelerate the
motor to the setpoint speed or to synchronize it to the network, the pulse enable may
takes place with the motor rotating. In this case, it is recommended that you activate the
"Flying restart" function (p1200 = 1) to prevent high current peaks.
● Changing the converter into "Ready to start and bypass" status after powering up, is of a
higher priority than switching back on automatically.
● Monitoring of the motor temperatures using temperature sensors is active while the
converter is in one of two statuses "Ready to start and bypass" or "Ready for operation
and bypass".
● The two motor contactors must be designed for switching under load.
Note
Information on the examples
The examples contained in the following descriptions are only basic circuits designed to
explain the basic function. The dimensions of specific circuit configurations (contactors,
protective equipment) must be calculated for specific systems.
NOTICE
Device damage as a result of incorrect phase sequence
The target frequency r3804 is specified as an absolute value. It does not contain
information about the direction of the rotating field (phase sequence)!
If the phase sequence of the line voltage, which the system must synchronize with, does
not match the motor voltage phase sequence then this results in incorrect synchronization.
In the worst-case scenario, this can mechanically damage the plant or system.
• Ensure that the line voltage phase sequence matches that of the motor voltage. You can
Precondition
The bypass function is only possible for encoderless closed-loop speed control (p1300 = 20)
or V/f control (p1300 = 0...19) and when an induction motor is used.
Establishing the bypass function
The bypass function is part of the "technology controller" function module that can be
activated by running the commissioning Wizard. Parameter r0108.16 indicates whether the
function module has been activated.
612
correct the phase sequence as follows:
– Interchange the two feeder cables at the converter output or at the line contactor.
– Correct the phase sequence of the motor or converter output voltage using p1820 or
p1821.
Operating Instructions, 12/2018, A5E36652151A
Enclosed Drives
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