Motor Connected Check Feature
Motor Connected Check
Before the drive starts running it checks that each individual motor (output) phase is connected by sending a pulse of current to each phase.
If the drive detects that any motor phase is not connected, the drive will trip to prevent running with a missing phase.
This feature is enabled by default and is performed each time a run command is given if the feature is enabled.
Motor Connected Check - Setup
Below is a guide to setup and optimise the Motor Connected Check function:
| Motor Connected Check Timing Diagram  |
NoteIf P10-08 is set to 0.0% the Motor Connected Check is disabled and is not performed during the start sequence. This means that if a motor phase is missing the drive could potentially start and run with a missing phase. | |
Parameter Number | Parameter Name | Units | Default | Available Settings | Access | Change During Run | Scaling | Size (Bytes) | CAN Register | CAN Sub Index | Modbus Register |
|---|---|---|---|---|---|---|---|---|---|---|---|
P10-08 | Motor Connected Check | % | 5.0% | 0.0 ... 100.0% | RW | N | 1 = 0.1% | 2 | 23F0h | 0 | 1008 |
To ensure that the motor is connected, the drive has a function which checks that at each start command all 3 phases of the motor are connected prior to releasing the electro-mechanical brake.
This function checks for breaks in the connection between the drive and the motor, for example a broken cable or a faulty contactor.
The drive will trip “OUt-Phx” if the drive detects the motor is not connected, where x is the phase that is missing e.g. "Oph-U"
Setting 0.0 means function is disabled and no check is performed. Note that the trips are still active and will detetct while running but not before running if 0.0 is set.
The default value is in general suitable for most applications, this value can be reduced to reduce the audible noise when the test is performed. The correct value is one in which the audible noise level is acceptable, but the drive still detects a missing motor phase should it not be connected.
If the Motor Connected Check is active and detects that motor phases are not connected to the drive you will get these errors:
Display message | No. | Description | Corrective Action/Further information |
|---|---|---|---|
Oph-U | 85 | Output (Motor) U Phase Loss | U phase is not connected to the drive, check that output contactors are closing fully, not arcing, or not opening whilst the drive is running, and see P10-08 (Motor connected check). |
Oph-V | 86 | Output (Motor) V Phase Loss | V phase is not connected to the drive, check that output contactors are closing fully, not arcing, or not opening whilst the drive is running, and see P10-08 (Motor connected check). |
Oph-wW | 87 | Output (Motor) W Phase Loss | W phase is not connected to the drive, check that output contactors are closing fully, not arcing, or not opening whilst the drive is running, and see P10-08 (Motor connected check). |
Out-PH | 49 | Output Phase Loss | Check all 3 motor phases are connected, confirm that motor contactor is closing. |
Below are a few common problems encountered and simple solutions:
Problem | Solutions | Note |
|---|---|---|
Motor Connected Check does not happen | Check that P10-08 has a value > 0.0 | For the Motor Connected Check to be active P10-08 MUST have a value > 0.0 |
Drive trips during Motor Connected Check | Check that all three motor phases are properly connected to the drive | All three motor phases must be connected for this test to be complete |