a10jp
Electrical
- May 18, 2005
- 150
Earlier this month, one of satallite field office has a project where the switching connection between 2 frequency converters (no.1 and no.2, 1MVA each) were supposed to be tested.
During thr testing, according to eye witness, something happened in the rotation of the generator and the phase shift device that tore the phase shift motor apart from the skid mount and its anchor bolts.
The cause of the problem, might be attributed to the switching the phases of the cables that casued the phase shift error, as least Toshiba, the contractor for this portion of the work, has admitted to that.
The Toshiba operator apparently has not installed the phases of the cables correctly to the Converter no.1 during a switching test between the existing (Converter No. 1) and new unit (Converter No.2).
In addition, probably without confirmation of the cable settings, the Toshiba operator has proceeded with the testing without confirmation of the sequence of operation at the control panels.
Currently the extent of the damage has been studied based upon visual inspection of the gearing and misalignment of motor, caused by the damage. The internal insulation of the stator (and perhaps the rotor) coils has not been accessed to and verified. The internal bearing of the rotating mechanism may also have been misaligned, but none of these could be deemed conclusive as to the extent of the damage until the generator unit is opened and examined.
We would like to come up with a comprehensive list of testing required to present to the contractor. But I am wondering if anyone out there who might have experience with this subject and knwo what to test and where to look for the problem. Probaly the shaft and bearing might have already been damaged by the rotational torque. We also suggested to test the insulation of the stator and rotor coils. But are there any other tests that might be recommended?
During thr testing, according to eye witness, something happened in the rotation of the generator and the phase shift device that tore the phase shift motor apart from the skid mount and its anchor bolts.
The cause of the problem, might be attributed to the switching the phases of the cables that casued the phase shift error, as least Toshiba, the contractor for this portion of the work, has admitted to that.
The Toshiba operator apparently has not installed the phases of the cables correctly to the Converter no.1 during a switching test between the existing (Converter No. 1) and new unit (Converter No.2).
In addition, probably without confirmation of the cable settings, the Toshiba operator has proceeded with the testing without confirmation of the sequence of operation at the control panels.
Currently the extent of the damage has been studied based upon visual inspection of the gearing and misalignment of motor, caused by the damage. The internal insulation of the stator (and perhaps the rotor) coils has not been accessed to and verified. The internal bearing of the rotating mechanism may also have been misaligned, but none of these could be deemed conclusive as to the extent of the damage until the generator unit is opened and examined.
We would like to come up with a comprehensive list of testing required to present to the contractor. But I am wondering if anyone out there who might have experience with this subject and knwo what to test and where to look for the problem. Probaly the shaft and bearing might have already been damaged by the rotational torque. We also suggested to test the insulation of the stator and rotor coils. But are there any other tests that might be recommended?
