SMA America, LLC
AC Voltage Configuration
Installation Guide
SB50US-80US-eng-IUS112633
21
Tightening torque of the screw terminals for the left terminal block:
4. Connect and fasten all cables not being used to the right terminal block (C). Tightening torques
of the screw terminals for the right terminal block (cables not being used):
Automatic Grid Voltage Detection
The Sunny Boy automatically detects the grid voltage that it must feed in. Depending on the voltage
and the phase angle between L1‑N and L2‑N, the inverter determines whether it is connected to a
208 V, 240 V or 277 V grid. If the Sunny Boy is configured for the wrong grid voltage (for example,
the inverter was configured for 240 V and then connected to a 208 V grid), the Sunny Boy displays
an error message.
The table below contains the limiting values for voltage and frequency in the AC terminal:
If the power distribution grid uses a neutral conductor, the responsible authority can demand that a
neutral conductor be connected to the inverter.
To set the configuration jumpers, observe the procedure in 4.4 ”Jumper for System Configuration”
(page 23).
To connect a neutral conductor to the Sunny Boy, observe section 6.4.2 ”AC Connection without
SMA DC Disconnect” (page 41) or section "AC Wiring with SMA DC Disconnect" on page 43.
Configuration of Grid Voltage
The figure on the next page illustrates common grid forms. Note that it is not the phase relationship
that is important when connecting the Sunny Boy to the power distribution grid, but the voltage
compatibility.
Gray terminal blocks (Weidmüller)
18 in-lbs. (2 Nm)
Green terminal blocks (Phoenix)
22 in-lbs. (2.5 Nm)
Do not remove the cable in the left terminal block with the marking 0 V (B).
This always remains connected to the right side of the left terminal block.
Gray terminal blocks (Weidmüller)
11 in-lbs. (1.2 Nm)
Green terminal blocks (Phoenix)
15 in-lbs. (1.7 Nm)
If the Sunny Boy is configured for the wrong
input voltage, this error message appears in
the display:
• Check if the configuration of the AC voltage is correct.
Voltage range for 208 V nominal value, phase-phase
(not Sunny Boy 8000-US)
183 V … 229 V
Voltage range for 240 V nominal value, phase-phase
211 V … 264 V
Voltage range for 277 V nominal value, phase-neutral conductor
244 V … 305 V
Frequency range
59.3 Hz … 60.5 Hz
