Rockwell Automation 7000A PowerFlex Medium Voltage Drive (A-Frame) - Classic Control - Manual (Page 240)

4-66 Commissioning
7000A-UM150F-EN-P – June 2013 7000 “A” Frame
Input Phasing Check
There are 3 voltage test points on the Line Signal Conditioning
Board that will allow you to look at each voltage connection
individually.
These test points are labeled as follows:
Table 4.C – SCBL Test Points and Associated Voltage Signals
Test Point
Description
Isolation Transformer:
Secondary Phasing and Bridge
Phase Relationship with
respect to Vab1-Out (2U)
Vab1-Out 2U Master –
Vbc1-Out 2V Master -120°
Vca1-Out 2W Master -240°
All of these test points can be measured to either the Analog Ground
on the board or the TE ground in the low voltage section. You can
use Vab1-Out as your reference (trigger on this waveform) and
verify all the other test points using the table above. It is easier to
use zero crossings on your oscilloscope as the reference points when
checking the phase shifts.
Essentially, you are verifying the following relationships:
1. V and W in each bridge should be lagging U by 120° and 240°,
respectively.


1) Ref A: 5 Volt 2 ms
2) Ref B: 5 Volt 2 ms
V
BCX-OUT
V
ABX-OUT
For 60 Hz systems, 360° = 16.7 ms.
For 50 Hz systems, 360° = 20 ms.