Installation – Magnum Energy MS-AEJ Series User Manual

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2.2.1 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. A #8 AWG (8.4 mm

) ) copper

conductor will serve as an AC Grounding Electrode Conductor (GEC –AC) for AC power conductors

smaller than and including #2/0 AWG (67.4 mm

) copper. See Table 2-1 for additional values.

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 (see fi gure 2-5): 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.

Table 2-1, AC Grounding Electrode Conductor Sizing

Figure 2-5, Multiple Connections to DC Ground Rod (Method 1)

A C

D C S e rvice

P a n e l

A C S e rvice

P a n e l

D C E lec tric al S y s tem

A C E lec tric al S y s tem

N eutral

Positive

N egative

D C

G rounding

S y s tem

N e g a tive

S B J

GE C -A C

E GC - A C

AC Ground

D C Ground

S B J

E GC - D C

N e u tra l

H ot

GE C -D C

GB B

Grounding Electrode

(D C side dedicated)

Grounding Electrode

(AC side dedicated )

M S -A E S e rie s In ve rte r/C h a rg e r

B C

Size of Largest

Ungrounded Conductor

(Copper)

Minimum Size of

Grounding Electrode

Conductor (Copper)

2 AWG or smaller

#8 AWG

1 or 1/0 AWG

#6 AWG

2/0 or 3/0 AWG

#4 AWG

Over 3/0 AWG

through 350kcmil

#2 AWG

AC Grounding Electrode Conductor Sizing

Installation