Dc Current After Ac-Side Disconnection; Checking The Pv Array For Earth Faults - SMA Sunny Boy 3000TL Installation Manual

12 Troubleshooting

12.4 DC Current after AC-side Disconnection

In spite of the AC side having been disconnected, a current is still detectable in the DC cables with a
current clamp. This is not an error but normal behaviour of the inverter when in operation.
• Always disconnect the inverter on the AC and DC sides (see Section 9.2 "Disconnecting the
Inverter from Voltage Sources", page 64).

12.5 Checking the PV Array for Earth Faults

If the red LED is lighting and the inverter displays event number "3501", "3601" or "3701", then there
is probably an earth fault in the PV array.
Check the strings for earth faults as described below:
1. Disconnect the inverter from voltage sources and open it (see Section 9.2 "Disconnecting the
Inverter from Voltage Sources", page 64).
Excessive voltages can destroy the multimeter
• Only use multimeters with a DC input voltage range up to at least 1,000 V.
2. Measure the voltages between the positive pole of
each string and the earth potential (PE).
3. Measure the voltages between the negative pole of
each string and the earth potential (PE).
4. Measure the voltages between the positive and
negative poles of each string.
84 SB30-50TL-21-IA-en-21
SMA Solar Technology AG
Installation Manual