SMA SB 1300TL Service Manual - Manual (Page 20)

Position Designation
B Middle varistor lead
C Lower varistor lead with loop
Destruction of the inverter due to overvoltage
If varistors are missing, the inverter is no longer protected against overvoltage.
• Do not operate the inverter without varistors in PV systems with a high risk of overvoltages.
• Do not recommission the inverter until the defective varistors have been replaced.
If no ground fault was detected in the PV system, check the function of the varistors as described
below:
Procedure:
1.
Danger to life due to high voltages
• Disconnect the inverter from all voltage sources (see Section 2.2, page 7).
2. Remove all screws from the enclosure lid and pull the enclosure lid forward smoothly.
3. Remove the grounding conductor from the bottom of the enclosure lid.
4. Use a measuring device to measure whether
there is a conductive connection between the
upper and the middle varistor lead.
If there is no conductive connection, the varistor is defective. SMA Solar Technology AG
recommends replacing all varistors immediately.
4.2.4 Replacing the Varistors
Proceed as follows to replace each varistor.
Procedure:
1.
Danger to life due to high voltages
Disconnect the inverter from all voltage sources and open the enclosure lid (see Section 2.2,
page 7).
2. Remove all screws from the enclosure lid and pull the enclosure lid forward smoothly.
3. Remove the grounding conductor from the bottom of the enclosure lid.
4 Troubleshooting SMA Solar Technology AG
Service Manual SB13-21TL-SG-en-11 20