Checking the function of the varistors, 8 checking the function of the varistors – SMA SMC 9000TL Installation User Manual
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SMC9-11TLRP-IA-en-51
Installation Manual
10 Troubleshooting
SMA Solar Technology AG
If the red LED is flashing and the inverter displays the message Check Varistor, one of the varistors
may be defective. Check the function of each varistor as described in the following.
Position of the Varistors
10.8 Checking the Function of the Varistors
Figure 15:
Varistors inside the inverter
Item
Designation
A
Left-hand connection wire with loop
B
Middle connection wire
C
Right-hand connection wire
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 plants 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 up to 1,000 V.