© 2016 Sensata Technologies
19
Appendix D – Installing Battery-based Inverters
Installing a MicroGT AC Coupled PV System
AC coupling is the ability to connect the inverter’s AC input and
output circuits in parallel, and to use utility power to continue to
power loads and charge the batteries from the AC side.
Creating an AC Coupled System
In a basic PV installation, a battery-less, grid-tie microinverter
system utilizes renewable energy to offset power consumption from
the utility grid. However, with that system, the grid-tie microinverters
must shut down during a utility power outage. Thus, your critical
loads are no longer powered, and all the energy produced by your
PV system during the outage is wasted.
In an AC coupled system, all the energy sources and loads are
connected directly to the AC side (Figure 13). Installing a bi-
directional battery-based inverter (i.e., Magnum Energy’s MS-PAE
Series) allows the existing battery-less, grid-tie microinverters to
operate, and therefore to continue to utilize the renewable energy
from your PV system to power the home’s critical loads during the
power outage—all from the AC side. The MS-PAE Series inverter
(
≥
Rev. 4.1) has a feature (“frequency shift”) that can be enabled
with an optional remote control (ME-RTR, ME-ARC, or ME-RC); this
feature allows the AC output frequency to shift when excess power
is generated on the AC side.
Note: Refer also to the instructions in the Installation section for
additional info and cautions during installation.
To install a MicroGT 500 AC Coupled PV system:
1. Mark the location of each MicroGT 500 inverter on the PV rack.
2. Mount and attach a MicroGT inverter at each of the identi
fi
ed
locations using hardware recommended by the PV module
racking manufacturer (Figure 5).
3. Connect the DC cables from the PV modules to the MicroGT 500
microinverters using the MC4 connectors (Figure 6).
4. Connect the grounding electrode conductors to the MicroGT
500s’ ground clamps (Figure 7).
5. Plug the female AC connector of the
fi
rst MicroGT inverter into
the male connector of the next microinverter (Figure 8), and so
on, to form a continuous AC branch circuit.
6. Install a protective end cap on the open AC connector of the last
microinverter in the AC branch circuit (Figure 9).
7. Route the open ends of the AC connector cable and the AC
branch circuit cable in to the sub panel. Secure both cables
using an appropriate gland/strain relief
fi
tting.
8. Route and connect the sub panel to your Magnum MS-PAE
inverter using appropriate wiring.
9. Route and connect the your Magnum MS-PAE inverter to the
main utility panel using appropriate wiring.
