Additional Functions; Load Shedding - SMA Sunny Island 5048 Technical Description

Additional Functions

12 Additional Functions
12.1 Load Shedding
The Sunny Island can automatically switch off loads to protect the batteries from deep discharge. To
do this, an external (AC or DC) power contactor must be installed between the Sunny Island and the
loads (see also section 21 "Accessories" (page 204)).
NOTICE!
Faulty system operation due to lack of load shedding.
• Install external load-shedding protection in case the off-grid system on the
AC-generating side is coupled to PV generators or wind generators.
• If there is overloading due to low energy production or very high energy
consumption, you must be able to switch off loads.
• Always switch off the loads, never the energy generators (e.g., Sunny Boy)!
Soc [%]
80
Lod1SocTm2 Stp
40
t2
30
Lod1SocTm2 Str
0h
The graphic shows an example for the settings that minimize the load shedding function at night.
From 6:00 a.m. to 22:00 p.m. the load shedding is activated for a charge state (SOC) of 40 %,
during nighttime (from 22:00 p.m. to 6:00 a.m.), by contrast, the charge state of the battery is allowed
to go down to 30 % before the load-shedding contactor is activated.
The load shedding function can be assigned twice. In the parameters mentioned above, the "Lod1"
part represents the first assigned function and the "Lod2" part represents a second, identical function.
These two load shedding functions, which are dependent on the battery's state of charge, allow for
tiered load shedding in which, by using different SOC values, different priorities can be given to
various load groups.
88 SI5048-TEN093630
Lod1SocTm1 Stp
Lod1SocTm1 Str
6h
Lod1Tm1Str
t1
22h
Lod1Tm2Str
SMA Solar Technology AG
Lod1SocTm2 Stp
t2
Lod1SocTm2 Str
24h
Technical Description