SMA SB 3000-US - Manual (Page 83)

SMA America, LLC 11 Cleaning and Care
Installation Manual SB30-40-US-IA-en-34 83
Figure 26: Position of the DC varistors and string fuses
Requirement:
☐ Set with 3 replacement varistors including insertion tool must be available
(see Section 13 "Accessories", page 97).
1. Open the DC Disconnect (see Section 9.3).
2. Check whether the DC varistors are discolored or whether there is any other visible damage.
If DC varistors are visibly discolored or damaged, replace the DC varistors.
4. Disconnect the DC varistors:
• Disconnect the string connectors of all ungrounded DC cables from the PV array.
• Remove the 4 fuse extractors with string fuses from the fuse holders of the DC Disconnect.
• Remove the 4 string fuses from the fuse extractors.
• Insert the 4 fuse extractors without string fuses into the fuse holder of the DC Disconnect.
5. Ensure that no voltage is present at the DC varistors.
Position Designation Explanation
A DC varistors ‒
B Fuse holder For connecting 4 fuse extractors with
string fuses
3.
Danger to life due to short circuits in the DC varistors
Death or serious injury due to electric shock.
• Check whether current is flowing in the DC cables.