Dc Wiring - Magnum Energy MagnaSine Hybrid MSH3012RV Owner's Manual

2.4

DC Wiring

This section describes the inverter's required DC wire sizes, the recommended disconnect/
overcurrent protection, and how to make the DC connections to the inverter and the battery bank.
Refer to Figure 2-4 when connecting the DC wires.
WARNING: Even though DC voltage is "low voltage", signifi cant hazards may be
present, particularly from short circuits of the battery system.
CAUTION: The inverter is NOT reverse polarity protected—which means that if the
negative and positive battery voltage is connected backwards to the inverter, the
inverter will likely be damaged. You should verify the correct voltage polarity using a
voltmeter BEFORE connecting the DC wires. Before routing the wiring, color code the
DC cables/wires with colored tape or heat shrink tubing: RED for positive (+); WHITE
for negative (–); and GREEN (or bare copper) for DC ground, to avoid polarity problems.
CAUTION: DO NOT connect the battery cables to the inverter until all wiring is complete
and the correct DC voltage and polarity have been verifi ed.
CAUTION: To remove battery power from the inverter, disconnect the battery positive
connection before the negative connection. This requirement can prevent damage to
the inverter and/or an accessory connected to the inverter.
Note: When an accessory that is not powered by the inverter (e.g., ME-AGS-N and ME-BMK)
is installed and connected to the inverter (via a network communication cable), the battery
negative connection of the inverter and each accessory must be at the same potential
(i.e., electrically common with each other) until the positive connection of each device is
removed. This prevents a high impedance path developing between the connected devices
(i.e., inverter and accessories), which can cause the network cable to become the DC return
path to the battery—possibly resulting in permanent damage to all connected devices on the
network. This can be prevented if the battery negative connection of each device is always
connected before connecting/disconnecting any battery positive.
Refer to Figure 2-4 when connecting the DC wires, consider the following requirements to ensure
maximum performance:
The DC positive and negative cables connected to the inverter from the battery bank should be
tied together with wire ties/straps or electrical tape approximately every 6 inches (15.3 cm). This
helps improve the surge capability and reduces the effects of inductance, which improves the
inverter waveform and reduces the wear of the inverter's fi lter capacitors. Keeping the battery
cables close together also reduces the chance of radio frequency interference.
Crimped and sealed copper ring terminal lugs with a 5/16" hole should be used to connect the DC
wires to the inverter's DC terminals.
The battery bank voltage MUST match the DC voltage required by the inverter (i.e., 12-volt
battery bank for a 12-volt inverter) or the inverter may be damaged.
To ensure the maximum performance from the inverter, all connections from the battery bank to
the inverter should be minimized. The exceptions are the DC fuse and disconnect or the DC circuit
breaker—required at the battery to protect the DC wiring—in the positive line, and a DC shunt—to
allow battery charge state monitoring—in the negative line. Any other additional connection will
contribute to additional voltage drops, and these extra connection points may loosen during use.
All wiring to the battery terminals should be checked periodically (once a month) for proper
tightness. The torque requirement for the DC terminals is between 10 to 12 ft lbf (13.6 to 16.3
N-m). If you don't have a torque wrench, ensure all DC terminals are tight and cannot move.
A brief spark or arc may occur when connecting the battery cables to the inverter DC terminals;
this is normal and due to the inverter's internal capacitors being charged.
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Installation
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