Testing And Replacing The Varistors; Dc Varistors - SMA Sunny Boy 6000TL‑US Installation Manual

SMA America, LLC
9.5 Testing and Replacing the Varistors
In regions where storms or other DC overvoltages frequently occur, the DC varistors loose their
functionality if the PV plant is not equipped with an additional overvoltage protection. To ensure that
the functionality of the DC varistors remains at a constant level, SMA recommends in such cases to
replace the DC varistors after an operating time of 10 years with new ones.
No protection against overvoltage due to faulty or missing varistors
Destruction of the inverter is possible.
• Do not operate the inverter with faulty varistors or no varistors at all.
• Replace faulty varistors immediately.
9.5.1 DC Varistors
Only the following inverter types are equipped with DC varistors:
SB 6000TLUS-12/SB 7000TLUS-12/SB 8000TLUS-12/SB 9000TLUS-12/
SB 10000TLUS-12/SB 11000TLUS-12.
Position Description
A

DC varistors

1. Disconnect the Sunny Boy on the AC and DC sides.
2. Wait 5 minutes for the component parts to cool down.
3. Open the DC disconnect as described in Section 8.3 "Opening the DC Disconnect", page 58.
Installation Manual
A
-
+ L1 L2 N
SB6-11TL-US-IA-en-13
9 Maintenance
65