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Introduction
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In a single inverter system, the meter is connected directly to the inverter. If your inverter
has a built-in revenue grade meter (RGM; the inverter is referred to a revenue grade
inverter), you can connect an external meter on the same bus as the RGM.
Fig 1.1
Meter Installation 2
2.1 Installation Guidelines
While Installing the meter, the National Electrical Code, ANSI/NFPA 70 and Canadian
Electrical Code C22.1. shall be used.
The meter is connected to the inverter using RS485.
AC wire specifications: 1.3 to 2.0 mm diameter / 22-18 AWG stranded wire, 600 V, type
THHN, MTW, or THWN.
RS485 wiring specifications:
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Cable type: Min. 3-wire shielded twisted pair (a 4-wire cable may be used)
Wire cross-section area: 0.32- 0.81 mm²/ 24-18 AWG (a CAT5 cable may be used).
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The meter is considered “permanently connected equipment” and requires a
disconnect means (circuit breaker, switch, or disconnect) and overcurrent protection
(fuse or circuit breaker).
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The meter draws 10-30mA, therefore the rating of any switches, disconnects, fuses,
and/ or circuit breakers is determined by the wire gauge, the mains voltage, and the
current interrupting rating required.
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The switch, disconnect, or circuit breaker must be located near the meter and be
easily operated .
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Use circuit breakers or fuses rated for 20A or less.
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Use grouped circuit breakers when monitoring more than one line.
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The circuit breakers or fuses must protect the mains terminals labeled L1and L2. In
the rare cases where neutral has overcurrent protection, the overcurrent protection
device must interrupt both neutral and the ungrounded conductors simultaneously.
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The circuit protection / disconnect system must meet all national and local electrical
codes.
Note
If using a cable longer than 10 m/33 ft in areas where there is a risk of
induced voltage surges by lightning, it is recommended to use external
surge protection devices. If grounded metal conduit is used for routing the
communication wires, there is no need for a lightning protection device.
2.2 Installing and Connecting the Meter
2.2.1
To mount the meter
1.The meter should be mounted in a Power Distribution Box.
2.Mount the meter on a 35mm DIN rail.
