SMA SB 2500TL-21 Installation - Manual (Page 76)

Troubleshooting SMA Solar Technology AG
76 SB25-30TLST-21-IA-en-13 Installation Manual
11.4 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 8.2 "Disconnecting the
Inverter from Voltage Sources" (page 57)).
11.5 Checking the PV Array for Earth Faults
If the red LED is glowing 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 and open it (see Section 8.2 "Disconnecting the Inverter from Voltage
Sources" (page 57)).
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.
Notice!
Excessive voltages can destroy the multimeter
• Only use multimeters with a DC input voltage range up to at least 1,000 V.