Testing And Replacing The Dc Varistors - SMA SUNNY BOY 5000-US Installation Manual

Maintenance
10.6 Testing and Replacing the DC Varistors
Only the following inverter types are equipped with DC varistors:
SB 5000US-12/SB 6000US-12/SB 7000US-12/SB 8000US-12.
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.
NOTICE
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.
Position Description
A Terminals for DC varistors
B Fuse holders for fuse extractor with string fuses
1. Disconnect the Sunny Boy on the AC and DC sides.
2. Wait 5 minutes for the components to cool down.
3. Open the DC disconnect as described in Section 6.4 "Opening the DC Disconnect" (page 40).
DANGER
High voltages at the DC terminals with connected PV modules
Risk of death or serious injury when touching the DC terminal.
• Do not touch any live component of the DC terminals.
88 SB50US-80US-IA-en-36
SMA America, LLC
Installation Manual