8
105. AC Connections
CAUTION:
A) All
LG
inverter system units contain hazardous AC and DC voltages. Because of these voltages, a qualified electrician
must install the
LG
inverter system, AC line service, and batteries. The electrician must install the AC line service
according to local, state and NEC codes and must be familiar with batteries and battery installation.
B) Before installing, maintaining, or servicing the unit, always remove or shut off all sources of AC and DC power to the
LG
inverter system. Turn off the AC line input circuit breaker at the service panel and place the
LG Battery Switch S2
in the
OFF
position to make sure the unit will not supply output voltage.
C) Whenever AC and/or DC voltage is applied, there will be AC voltage inside the LG inverter system unit; the unit can
supply power from AC line or from its batteries. To avoid equipment damage or personal injury, always assume that
there may be voltage inside the LG inverter system.
D) Remove rings, watches, and other jewelry before installing the AC wiring. Always wear protective clothing and eye
protection and use insulated tools when working near batteries. Whenever servicing an energized unit with the inside
panel open, electric shock is possible; follow all local safety codes.
TEST BEFORE TOUCHING!
E) To reduce the risk of fire or electric shock, install the
LG
inverter system and the batteries in a temperature-controlled
and humidity-controlled indoor area free of conductive contaminants. See
Section 103
for operating environment
specifications.
105.1 AC Wiring Preparations
1) Remove the system’s front cover. Make sure the
LG Battery Switch S2
is in the
OFF
position.
2) Make sure the
LG
inverter system input and output voltages are correct for the particular application. Remember that
the
LG
system provides single-phase power only.
3) The input circuit breaker in the input service panel provides the means for disconnecting AC to the
LG
inverter sys-
tem. Only authorized persons shall be able to disconnect AC to the unit. (See
NEC 700-20 and 700-21
.)
CAUTION: To prevent electrical shock or equipment damage, for all units, the LG Battery Switch S2 and the
AC input circuit breaker at the service panel are all OFF before making AC connections to the LG inverter
system.
4) If not previously done, remove cabinet knockouts for AC Input and AC Output as described in
Sections 104-4, 104.5
or 104.6
depending on mounting method
CAUTION: Do not drill the cabinet; drill filings may damage the unit and prevent it from operating. If larger
knockouts are needed, use a chassis punch to enlarge the appropriate knockout. Do not add additional or
unnecessary knockouts.
5) Install the input and output conduits.
6) Run the AC Input service conductors and AC Output conductors through separate conduits.
LG
inverter system emer-
gency output circuits shall be installed in dedicated conduit systems and not shared with other electrical circuits as
described in
NEC 700-9(b)
.
105.2 AC Input and AC Output Connections
CAUTION: Prior to making any wiring connections to unit make sure branch AC input circuit breaker feeding
the LG unit is turned off at the service panel!
The
LG
models can be configured for various modes of operation and are described in this section. Refer to the
appropriate wiring diagrams to properly connect the utility AC power, fixtures and external switching device (where
applicable). Perform all wiring procedures in accordance with applicable codes.