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2017 Sensata Technologies
Installation
AC
DC Service
Panel
AC Service
Panel
DC Electrical System
AC Electrical System
Neutral
Positive
Negative
DC
Grounding
System
Negative
SBJ
GC
GEC-AC
EGC-AC
AC Ground
DC Ground
SBJ
EGC-DC
GC
Neutral
Hot
GEC-DC
GE
GBB
GBB
Grounding Electrode
(DC side dedicated)
MS-PAE Series Inverter/Charger
Figure 2-15, Method 3 – DC Ground Rod with Single Connection
Method 3 (see Figure 2-15):
The AC grounding electrode conductor (GEC–AC) is bonded to the
DC ground point and the DC grounding electrode conductor (GEC–DC) is the
only connection
to
the grounding electrode (GE), which must be a rod, pipe, or plate electrode.
In this method, since there is only one connection to the ground rod, the DC grounding electrode
conductor (GEC–DC) is not required to be larger than #6 AWG (13.3 mm
2
) copper. The reasoning
for allowing this smaller grounding electrode conductor is that it is only required to stabilize the
system voltage with respect to earth, and the other properly-sized conductors in each electrical
system will safely carry any fault currents if they occur.
Figure 2-14, Method 2 – DC Ground Rod with Multiple Connections
(using a single grounding electrode)
AC
DC Service
Panel
AC Service
Panel
DC Electrical System
AC Electrical System
Neutral
Positive
Negative
DC
Grounding
System
Negative
SBJ
GC
GE
GEC-AC
EGC-AC
AC Ground
DC Ground
SBJ
EGC-DC
GC
Neutral
Hot
GEC-DC
GBB
GBB
Grounding Electrode
(AC and DC sides shared)
MS-PAE Series Inverter/Charger
Method 2 (see Figure 2-14):
When the AC and DC service panels are near each other, then the
AC grounding electrode conductor (GEC–AC) and DC grounding electrode conductor (GEC–DC)
can be connected to a single grounding electrode (GE). In this method—since there are multiple
connections to the DC grounding electrode—the size of the DC grounding electrode conductor
(GEC–DC) cannot be smaller than the largest conductor in the DC system (usually the battery-
to-inverter cable).
