System Grounding - Fujitsu M2361A Customer Engineering Manual

2.7.4 Syste. grounding
(1) Definitions of SG, FGl and FG2.
SG is Signal ground or DC ground and is isolated from AC ground within the
drive.
FGl is Frame ground or AC ground and is a direct short to chassis.
FG2 is a high impedance AC ground, connected to FGl through a
510
Kohm
resistor.
For shipment, SG is connected to FG2 with the shorting plate, as shown in
Figure 2.7.7.
FGI
SG
FG2
I
AlM
l
....----.,
....----.,
[) [) [) [)
[)
[) [)
...
'--"
\
(Direct connection)
\
Shorung Plate
FGI
SG
FG2
I
ALM
l
r----.
[) [) [)
~
[)
[) [) [)
'-
'--"
(Connection through 51 OKn>
Figure 2.7.7 Connection of FG and SG
(2) Grounding methods
It is always recommended that drives be grounded, and it is required if
cable lengths longer than 10 ft. are used or if the drives are connected
in the daisy-chain configuration. All grounding should be done with flat
braided wire, preferably covered with a jacket or tubing.
Grounding methods very with site and system integration design, and are
commonly derived in a trial-and-error fashion. However, three approaches
are offered in order of preference:
a.
b.
c.
2 - 16
Connect SG to FGl with the shorting plate. Connect a flat braid wire
from SG to controller ground. If daisy-chained, daisy-chain the
braid from SG to SG as shown in Figure 2.7.8.
Leave SG connected to FG2 (shipping configuration) and connect a flat
braid wire to controller ground. If daisy-chained, daisy-chain the
braid from SG to SG as shown in Figure 2.7.9.
Remove the shorting plate, isolating SG and FG grounds. Connect a
flat braid wire from SG to controller ground (preferably DC ground).
In this case, the braided wire must be covered to prevent accidental
shorting to chassis (AC ground).
B03P-482S-0002A ••• Ol