SMA SUNNY BOY 3.0-US Instrucciones De Servicio Técnico página 9

SMA Solar Technology AG
5.
Danger to life due to high voltages on the DC-in connecting terminal plate
When exposed to sunlight, the PV array generates dangerous direct voltage. Touching the
DC conductors can lead to lethal electric shocks. Even if the DC load-break switch of the
inverter is in the O, position, there will be dangerous direct voltage present in the DC
conductors and on the DC-in connecting terminal plate in the Connection Unit.
• If an external DC disconnecting switch is available, open the external DC disconnecting
switch.
• If there is no external DC disconnecting switch, cover the PV modules with opaque
material (e.g. foil).
• Ensure that there is no voltage on the DC conductors of the PV array.
• Wait five minutes before working on the inverter.
• Leave the DC-in connecting terminal plate plugged into the Connection Unit and only
touch it on the black enclosure.
6. Wait until the LEDs have gone out.
7. Unscrew all six screws of the enclosure lid of the Connection Unit with a Torx screwdriver (TX
25) and remove the enclosure lid carefully toward the front. While doing so, note that the
display assembly on the enclosure lid and the communication assembly in the inverter are
connected via a ribbon cable.
8. Disconnect the display cable from the socket on
the communication assembly.
9. Use a current clamp to ensure that no current is present in the DC conductors.
10. Ensure there is no voltage on the AC-out connecting terminal plate between L1 and N and L2
and N using a suitable measuring device. To do this, stick the test probe (max. diameter: 2 mm
(0.078 in)) in each rectangular opening of the terminal.
11. Ensure there is no voltage on the AC-out connecting terminal plate between L1 and the
equipment grounding conductor and L2 and the equipment grounding conductor using a
suitable measuring device. To do this, stick the test probe (max. diameter: 2 mm (0.078 in)) in
each rectangular opening of the terminal.
Service Manual
5 Disconnecting the Inverter from Voltage Sources
SB30-77-1SP-US-40-AT-COM-SG-xx-10 9