SMA Solar Technology AG SUNNY TRIPOWER 10000TL, Service Manual For Installers

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6 Checking the Function of the Varistors
If the inverter is equipped with varistors and the error message 7401 occurs, the function of the
varistors needs to be checked.
Overview of the varistors
Figure 2: Position of the varistors inside the inverter
Check the function of each varistor as described in the following:
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.
Destruction of the measuring device due to overvoltage
• Only use measuring devices with a DC input voltage range of 1000 V or higher.
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).
6 Checking the Function of the Varistors SMA Solar Technology AG
Service Manual for Installers STP5-12TL-20-SG-en-13 22
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