Sonnen sonnenBatterie ecoLinx 10, Инструкция по установке и эксплуатации, Страница: 20 / 64

12
NEC 705.12(D)(2) calculation
Because residential energy storage is a new
and emerging technology, some installers and
inspectors are unfamiliar with how to take the
sonnenBatterie ecoLinx storage system into
account when sizing distribution panels in regards
to NEC 705.12(D)(2), the 120% rule. Because
the storage system has dedicated grid and
microgrid ports, only load centers located on the
microgrid side need to take the output of the
sonnenBatterie ecoLinx into consideration.
The storage system only discharges energy
when loads are present “downstream”; that is,
on the protected load panel. This is in contrast
to a PV system, which supplies energy whenever
grid voltage is present. Because of this, the main
service panel should be sized for only grid and PV,
if applicable. The protected load panel, however,
needs to take the grid supply overcurrent
protection device, PV, and the storage system into
account for proper rating.
The storage system incorporates an internal
power meter to measure loads. This meter uses
current transformers on the microgrid side of
the storage system to determine when loads
are present and how much energy to discharge.
Because of this design, the storage system will not
discharge more energy than necessary to power
loads on the microgrid. The main distribution
panel, located on the grid side of the storage
system, need not take the sonnenBatterie ecoLinx
into consideration because the storage system will
not discharge to upstream loads.
The overcurrent protection device used to
supply the sonnenBatterie ecoLinx can be up to
200 amps, based on the storage system’s internal
ATS and wiring, as the sonnenBatterie ecoLinx will
act as a pass-through for the grid power to serve
the load distribution panel. PV in excess of loads
also has a path to the grid from the microgrid load
distribution panel. See the example illustration
below.
ecoLinx output
sonnen ecoLinx max output
Fig. 6 NEC 705.12(D)(2) calculation example