Magnum Energy MP Extension Box (MPX Series) User Manual

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3.0 Installation

IMPORTANT: Damage may occur if DC power is connected to the MP enclosure before the

Communication wiring is completed. DO NOT connect the DC cables from the MP enclosure

to the battery bank until: 1) all DC, AC, and Comm wirings are completed, 2) the correct DC

and AC overcurrent protection have been installed and, 3) the correct DC voltage and polarity
have been verified.

MPXS-30D DC Wiring

This section covers the DC wiring to/from the inverters, and from the battery bank.

WARNING: During normal operation, the terminals, busbars, and electrical components

inside the MP enclosure may be energized – DO NOT TOUCH. Disconnect all power sources

before removing the cover.
WARNING: Use precaution when working with the DC/battery system, even though it is

a “low voltage” system signifi cant hazards may be present, particularly if short circuits

occur.
CAUTION: DO NOT connect the battery cables to the battery bank until all wiring to

the inverters and inside the MP/MPX enclosures is complete, and the correct DC voltage

and polarity have been verifi ed.

Installing DC Cables from Inverters to MP (see Fig. 3-18c - MPSL-30D, Fig. 3-19c - MPSH-30D)

WARNING: Ensure all AC and DC breakers are switched OFF before connecting or dis-

connecting the battery cables, and that all AC and DC power is disconnected from the

inverter.
WARNING: Lethal currents will be present if the positive and negative cables attached

to the battery bank touch each other. During the installation and wiring process, ensure

the cable ends are insulated or covered to prevent touching/shorting the cables.
CAUTION: The Magnum inverter is NOT reverse polarity protected, if this happens the

inverter will be damaged and will not be covered under warranty. Before making the

fi nal DC connection

from the MP enclosure down to the battery bank, verify the correct

battery voltage and polarity by using a voltmeter. If the positive (+) terminal of the bat-

tery is connected to the negative

(–)

busbar of the MP enclosure and vice versa, severe

damage will result. Ensure the cables are color-coded to avoid polarity confusion.

1. Route a DC positive battery cable (red) from the battery bank thru the bottom of the MP

enclosure for each inverter.

2. Connect the end of each DC positive battery cable (red) to a DC circuit breaker’s bottom battery

positive connection.

IMPORTANT: Coordinate the DC wiring to each inverter from each DC breaker such that the

far left inverter (Master) is connected to the far left breaker (Master DC breaker), and the

second inverter (Slave 1) is connected to the second DC breaker (Slave 1 breaker), and so on.

1. Route a DC positive cable (red) from each inverter into the MP enclosure.
2. Connect the end of the DC positive cable (red) to the inverter’s positive DC terminal.
3. Connect the other end of the DC positive cable (red) to a DC circuit breaker’s top terminal.
4. Route a DC negative cable (black) from each inverter into the MP enclosure.
5. Connect the end of the DC negative cable (black) to the inverter’s negative DC terminal.
6. Connect the other end of the DC negative cable (black) to the top of the DC shunt’s busbar.
7. Route an appropriately sized DC equipment ground wire from each new inverter’s DC GROUND

terminal to the DC GROUND busbar in the MP enclosure.

8. Verify all DC connections are torqued from 10 to 12 ft lbf (13.6 to 16.3 N-m).
9. Once the DC connections are correctly wired and tested, coat the terminals with an approved

anti-oxidizing coating.

Installing the DC Cables From the Battery Bank to the MP Enclosure (see Figure 3-18d -

MPSL-30D, Figure 3-19d - MPSH-30D)