Power Wiring; Overview Of Power Connections; Chapter 4 Power Wiring - Baldor VS1SM Installation & Operating Manual

4.1

Overview of Power Connections

The recommended grounding method is shown in Figure 4‐1.
Safety Ground - (G)
This is the safety ground for the drive that is required by code. One of these points must be connected to
adjacent building steel (girder, joist), a floor ground rod, or bus bar. Grounding points must comply with
national and local industrial safety regulations and/or electrical codes.
See recommended tightening torques in Table 4‐1.
Note: A line reactor is recommended and
must be purchased separately.
AC Main
Four Wire
Supply
"Wye"
Safety
Ground
Route all 4 wires L1, L2, L3 and Earth
Driven Earth
(Ground) together in conduit or cable.
Ground Rod
(Plant Ground)
Motor Ground
The motor ground must be connected to one of the ground terminals on the drive.
Shield Termination
Either of the safety ground terminals located on the power terminal block provides a grounding point for
the motor cable shield. The motor cable shield connected to one of these terminals (drive end) should
also be connected to the motor frame (motor end). Use a shield terminating or EMI clamp to connect the
shield to the safety ground terminal. The NEMA 1/IP30 Kit may be used with a cable clamp for a
grounding point for the cable shield.
When shielded cable is used for control and signal wiring, the shield should be grounded at the drive end
only, never at both ends.
RFI Filter Grounding
Using single-phase drives with integral filter, or an external filter with any drive rating, may result in
relatively high ground leakage currents. Therefore, the filter must only be used in installations with
grounded AC supply systems and be permanently installed and solidly grounded (bonded) to the building
power distribution ground.
Ensure that the incoming supply neutral is solidly connected (bonded) to the same building power
distribution ground. Grounding must not rely on flexible cables and should not include any form of plug or
socket that would permit inadvertent disconnection. Some local codes may require redundant ground
connections. The integrity of all connections should be checked periodically.
MN761
Figure 4‐1 Recommended System Grounding
L1 L2
L1
Optional
L2
Line
Reactor
Route all 4 wires U, V, W and Motor Ground together in conduit or cable.
Connect all wires (including motor ground) inside the motor terminal box.
Note: Wiring shown for clarity of grounding
method only. Not representative of
actual terminal block location.
Drive
Note: A load reactor is recommended
Optional
Load
Reactor
Chapter 4

Power Wiring

and must be purchased separately.
Ground per NEC
and Local codes.
Power Wiring 4-1