Electrical Installation; System Grounding - Baldor 18H Series Installation & Operating Manual

Section 1
General Information

Electrical Installation

System Grounding

AC Main
Supply
Safety
Four Wire
Ground
Driven Earth
Ground Rod
(Plant Ground)
3-4 Receiving & Installation
Interconnection wiring is required between the motor control, AC power source, motor,
host control and any operator interface stations. Use listed closed loop connectors that
are of appropriate size for wire gauge being used. Connectors are to be installed using
crimp tool specified by the manufacturer of the connector. Only Class 1 wiring should be
used.
Baldor Series H controls feature UL approved adjustable motor overload protection
suitable for motors rated at no less than 50% of the output rating of the control. Other
governing agencies such as NEC may require separate over–current protection. The
installer of this equipment is responsible for complying with the National Electric Code
and any applicable local codes which govern such practices as wiring protection,
grounding, disconnects and other current protection.
Baldor Controls are designed to be powered from standard three phase lines that are
electrically symmetrical with respect to ground. System grounding is an important step in
the overall installation to prevent problems. The recommended grounding method is
shown in Figure 3-1.
Caution: Baldor recommends not using "Grounded Leg Delta" transformer
power leads that may create ground loops and degrade system
performance. Instead, we recommend using a four wire Wye.
Figure 3-1 Recommended System Grounding
L1
Optional
L2
Line
Reactor
L3
Earth
"Wye"
Route all 4 wires L1, L2, L3 and Earth
(Ground) together in conduit or cable.
Route all 4 wires T1, T2, T3 and Motor
Ground together in conduit or cable.
Connect all wires (including motor ground)
inside the motor terminal box.
JOG LOCAL PROG
FWD DISP
REV SHIFT ENTER
STOP RESET
Series H
Note: Wiring shown for clarity of grounding
L1 L2 L3 T1 T2 T3
Optional
Load
Reactor
method only. Not representative of
actual terminal block location.
Ground per NEC and
Local codes.
MN718