Installation
2.6.1
Sizing the Grounding Electrode Conductors
AC Side – The size of the AC grounding electrode conductor (GEC–AC) depends on the size of
the largest ungrounded conductor feeding the AC load center. One #8 AWG (8.4 mm
conductor will serve as an AC grounding electrode conductor (GEC–AC) for AC power conductors
smaller than and including #2 AWG (33.6 mm
Table 2-3, AC Grounding Electrode Conductor Sizing
Size of Largest
Ungrounded Conductor
#2 AWG (33.6 mm
#1 (42.4 mm
) to #1/0 AWG (53.5 mm
2
#2/0 (67.4 mm
) or #3/0 AWG (85.0 mm
2
Over #3/0 AWG (85.0 mm
through 350 kcmil
DC Side – To size the DC grounding electrode conductor, you must fi rst determine which one of the
following three methods will be used to connect the DC and AC grounding points in the inverter's
two electrical systems to the common "earth" ground:
Method 1 (Figure 2-11): This method uses a separate grounding electrode for the DC system
and the AC system. In this method—since there are multiple connections to the DC grounding
electrode (GEC–DC)—the size of the DC grounding electrode conductor cannot be smaller than
the largest conductor in the DC system (usually the battery-to-inverter cable).
The DC grounding electrode (GE–DC) must be bonded to the AC grounding electrode (GE–AC)
to make a grounding electrode system. This bonding conductor (BC) cannot be smaller than the
largest grounding electrode conductor, either AC or DC.
AC Service
GBB
Figure 2-11, Multiple Connections to DC Ground Rod (Method 1)
Page 24
) or smaller
2
)
2
AC Electrical System
MSH-RE Series Inverter/Charger
Panel
Hot
AC
Neutral
GC
Neutral
SBJ
AC Ground
EGC - AC
GEC-AC
GE
Grounding Electrode
(AC side dedicated)
) copper. See Table 2-3 for additional values.
2
Minimum Size of
Grounding Electrode Conductor
#8 AWG (8.4 mm
)
#6 AWG (13.3 mm
2
)
#4 AWG (21.1 mm
2
#2 AWG (33.6 mm
DC Electrical System
Positive
DC
GC
Negative
DC Ground
Grounding
EGC - DC
System
GEC-DC
GE
BC
Grounding Electrode
(DC side dedicated)
2
)
2
)
2
)
2
)
2
DC Service
Panel
Negative
SBJ
GBB
© 2013 Magnum Energy, Inc.
) copper