Magnum Energy MS-AEJ Series User Manual

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2.2.2 System Bonding Jumper
The MS-AE Series inverter does not include an internal bond between the Grounded Conductor

(AC neutral/DC negative) and the equipment grounding terminals. This bond [System Bonding

Jumper (SBJ)] is usually done in the main distribution panel for each electrical system.

CAUTION: There should be one and only one point in each electrical system (both AC and

DC) where the Grounded Conductor is attached to the Grounding Electrode Conductor.

AC Side – The size of the System Bonding Jumper (SBJ) in the AC electrical system is based on

the area of the largest AC ungrounded conductor. In accordance with the NEC, use Table 2-1 to

determine the System Bonding Jumper size compared to the largest AC ungrounded conductor.
DC Side - The size of the System Bonding Jumper (SBJ) in the DC electrical system must not be

smaller than the DC Grounding Electrode Conductor (GEC – DC) used, which is determined from

the grounding method that will be used (see section 2.6.1).
2.2.3 Equipment Grounding Conductor
The inverter case and all other non-current-carrying exposed metal surfaces in the entire elec-

trical system that may be accidentally energized must be grounded. The equipment-grounding

conductor must be sized to safely carry the maximum ground-fault current likely to be imposed

on it from where a ground-fault may occur. In accordance with the NEC, use Table 2-2 to size the

equipment-grounding conductors. This table requires that the equipment-grounding conductor

be sized according to the rating of the overcurrent device protecting the circuit.

CAUTION: The connections and wiring for the equipment-grounding conductor must be

continuous to allow fault currents to properly operate overcurrent devices. Where equip-

ment is removed and this disconnects the bonding connection between the grounding

electrode conductor and exposed conducting surfaces, a bonding jumper must be installed

while the equipment is removed.

AC Side - Where the AC output from the inverter is connected to an AC load center, there should

be an equipment grounding conductor connected between the inverter case and the grounding

point in the AC load center. The AC Equipment Grounding Conductor (EGC – AC) is sized per Table

2-2 and is connected to the inverter’s AC equipment grounding terminal shown in fi gure 2-12.
DC Side - Since the currents on the DC side are higher than the AC side (5 times at 24 volts, 2.5

times at 48 volts), the equipment grounding needs are different. The DC Equipment Grounding

Conductor (EGC – DC) is sized per Table 2-2 and connected to the DC equipment grounding terminal

on the inverter shown in fi gure 1-2 (item 12).

Table 2-2, Equipment Grounding Conductor Sizing

Rating of Overcurrent

Device

Minimum Size of

Copper Ground Wire

15 amp

#14 AWG

20 amp

#12 AWG

30 - 60 amp

#10 AWG

100 amp

#8 AWG

200 amp

#6 AWG

300 amp

#4 AWG

400 amp

#3 AWG

Equipment Grounding Conductor Sizing

Installation