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General grounding requirements, General grounding requirements on – Rockwell Automation 20A PowerFlex 70 Adjustable Frequency AC Drive User Manual

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Rockwell Automation Publication 20A-IN009D-EN-P - June 2013

PowerFlex 70 Adjustable Frequency AC Drive

General Grounding Requirements

Ground impedance must conform to the requirements of national and local
industrial safety regulations and/or electrical codes. Check the integrity of all
ground connections periodically.

For installations within a cabinet, a single safety ground point or ground bus bar
connected directly to building steel (girder, joist) can be used. All circuits
including the AC input ground conductor can be grounded independently and
directly to this point/bar.

Figure 11 - Typical Grounding

Safety Ground (PE)

This is the safety ground for the drive that is required by code. This point must be
connected to adjacent building steel (girder, joist), a floor ground rod or bus bar
(see

Figure 11

). Grounding points must comply with national and local industrial

safety regulations and/or electrical codes.

Shield Termination - SHLD

The shield terminal (see

Figure 7 on page 20

) provides a grounding point for the

motor cable shield. The motor cable shield can be connected to this terminal on
the drive (on the drive end) and the motor frame (on the motor end). A shield
terminating cable gland can also be used.

If you use shielded cable for control and signal wiring, the shield can be grounded
at the source end, and not the drive end.

IMPORTANT

The safety ground for the drive (PE) must be connected to system ground.

U (T1)
V (T2)

W (T3)

R (L1)

S (L2)

T (L3)

PE

SHLD