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Rockwell Automation 7000L PowerFlex Medium Voltage AC Drive (C Frame) - Classic Control User Manual

Page 278

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Commissioning 4-73

7000 “C” Frame

7000L-UM300I-EN-P – Juen 2013

Input Phasing Check

There are 9 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°

Vab2-Out

3U

Slave 1

-20°

Vbc2-Out

3V

Slave 1

-140°

Vca2-Out

3W

Slave 1

-260°

Vab3-Out

4U

Slave 2

+20°

Vbc3-Out

4V

Slave 2

-100°

Vca3-Out

4W

Slave 2

-220°

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.

2. 3U, 3V, and 3W should be lagging 2U, 2V, and 2W by 20°

(-20°), respectively.

3. 4U, 4V, and 4W should be leading 2U, 2V, and 2W by 20°

(+20°), respectively.