Arc-Fault Circuit Interrupter (Afci); Anti-Islanding Protection; String Fuses - SMA SUNNY BOY 3000-US Installation Manual

4 Product Description

4.6 Arc-Fault Circuit Interrupter (AFCI)

According to the National Electrical Code
arc detection and interruption.
An electric arc with a power of 300 W or greater must be interrupted by the AFCI in the time specified
by UL 1699B. A tripped AFCI may only be reset manually.
Only the following Sunny Boy device types are equipped with an automatic arc-fault circuit interrupter
(AFCI):
• SB 3000-US-12
• SB 3800-US-12
• SB 4000-US-12
The 2011 edition of the National Electrical Code
PV plants attached to a building must be fitted with a means of detecting and disconnecting serial
electric arcs on the PV side.
The automatic arc-fault circuit interrupter can be deactivated in the "Installer" mode via the
communication device if this function is not desired.

4.7 Anti-Islanding Protection

The Sunny Boy has an active safety algorithm to protect against islanding.
A stand-alone grid occurs when the power distribution grid is switched off and the Sunny Boy attempts
to continue to feed in to the power distribution grid. For this to happen, the remaining load must be
resonant at 60 Hz and exactly match the power of the Sunny Boy. The effect of the safety algorithm
is that, in the event of the power distribution grid being switched off, the PV plant does not supply any
current to a symmetrical load that is resonant at 60 Hz.

4.8 String Fuses

The DC Disconnect is supplied with 4 string fuses (one fuse per string) designed for 15 A and 600 V.
With string fuses, the DC Disconnect can protect the PV modules from potential reverse currents.
24 SB30-40-US-IA-en-33
®
, Section 690.11, the Sunny Boy has a system for electric
®
, Section 690.11, stipulates that newly installed
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Installation Manual