Sunny Boy 2000
Technical Description
SB2000-11:EE
- 14 -
SMA Regelsysteme GmbH
Criteria for disconnecting the Sunny Boy from the grid:
l
Mains impedance
-
The inverter does not start feeding to the mains if a maximum impedance value
is exceeded (Z
AC
= 1.25
Ω
).
-
If the mains impedance changes by a certain value in a certain time (Z
AC
≥
0.5
Ω
) or if it exceeds a maximum value (Z
AC
≥
1.75
Ω
) during grid feeding, the in-
verter will be disconnected from the mains within 5 s.
l
Mains voltage
-
In case the mains voltage exceeds or falls below a range of -15/+10 % of the
nominal mains voltage V
N
, the Sunny Boy is disconnected from the mains within
0.2 s.
l
Mains frequency
-
If the frequency exceeds a range of ± 0.2 Hz of nominal mains frequency f
N
with
a mains voltage of -30/+15 % of nominal mains voltage this must additionally
cause a mains disconnection within 0.2 s.
l
Insulation
The quality of insulation in the entire system is guaranteed by two independent
monitoring activities:
-
The inverter will only start feeding to the grid if its resistance to ground (insula-
tion resistance) exceeds 2 M
Ω.
-
During operation the fault current (to earth) is continuously monitored. If this cur-
rent exceeds 95 mA or if the value increases or decreases by more than 30 mA
the Sunny Boy is disconnected from the grid within 0.2 s.
The new concept of the Sunny Boy provides maximum safety. Nevertheless, the instal-
lation expenses of a solar plant are drastically reduced because now a one-phase con-
nection of the inverter with MSD is sufficient.
