Checking The Pv Plant For A Ground-Fault - SMA SUNNY BOY 3000-US Installation Manual

SMA America, LLC

11.6 Checking the PV Plant for a ground-fault

If the red and yellow LEDs glow, there may be a ground-fault in the PV plant.
Check each string of the PV plant for a ground-fault as per the following procedure:
Danger to life due to electric shock
Death or serious injuries due to high voltages at the PV array.
• Only touch the insulation of the PV array cables.
• Do not connect strings with ground-faults to the inverter.
Destruction of the measuring device due to excessive voltages
• Only use measuring devices with a DC input voltage range of at least 600 V.
1. Open the DC Disconnect (see Section 9.3).
2. Measure the voltages at all PV strings:
• Measure the voltages between the positive terminal and the PV protective conductor.
• Measure the voltages between the negative terminal and the PV protective conductor.
If there is a voltage between the negative terminal of a string and the PV protective conductor
or positive terminal of a string and the PV protective conductor, there is a ground-fault in the
string.
• The approximate position of the ground-fault can be determined from the ratio of the
measured voltages between the positive terminal against the PV protective conductor and
the negative terminal against the PV protective conductor.
• Eliminate the ground-fault.
If there is no ground-fault and the message continues to be displayed, contact the
SMA Service Line.
Installation Manual
11 Cleaning and Care
SB30-40-US-IA-en-33 85