SMA Solar Technology America LLC
4 Product Description
Installation Manual
CU1000-US-11-IA-en-13
17
4.5 String Fuses
String fuses are used to protect wiring and equipment from excessive currents that can cause damage,
heating, or in extreme cases, even fire.
In PV systems, the ampacity and voltage ratings of string fuses is determined by the electrical
specifications of the PV modules and
National Electrical Code
®
requirements. Refer to the PV module
datasheet or contact the manufacturer for technical specifications to determine required string fuse
ratings.
The maximum ampacity rating for string fuses in the Connection Unit is 20 A. The Connection Unit
Integration Kit includes 15 A string fuses. It is the responsibility of the system designer and installer to
determine the appropriateness of the supplied string fuses for any particular installation.
The minimum ampacity rating of the string fuses is calculated by means of the short-circuit current
rating (Isc) of the PV module. The
National Electrical Code
®
stipulates that all string fuses are
designed to be at least 1.56 times as large as the Isc of the PV module being used. The correct
ampacity rating of the string fuse is determined by calculating the minimum size and then rounding it
up to the nearest standard fuse rating.
Item
Quantity Description
A
2
1-inch conduit sections
Liquidtight Flexible Non-Metallic Conduit (LFNC-B)
B
4
1-inch conduit fittings
Non-metallic Liquidtight (NMLT) with locknuts
C
2
1-inch conduit fitting sealing washers
(for sealing conduit fittings at top Connection Unit openings)
D
2
1-inch liquidtight hole plugs
E
5
Output conductors leads
8 AWG, Copper, 1000 VDC, PV Wire
(2) - red (pos), (2) - black (neg), (1) - green (gnd)
F
16
String fuses
15 A, 1000 VDC, PV Fuses
Liquidtight Flexible Non-Metallic Conduit (LFNC-B)
The liquidtight flexible non-metallic (LFNC-B) conduits supplied in the Integration Kit are suitable
for FCC Part 15 Class A compliance for use in business/industrial/commercial environments.
If FCC Part 15 Class B compliance is required for use in a residential environment, metal
conduits (supplied by the installer) must be used.
Summary of Contents for CU 1000-US-11
Page 1: ...CU1000 US 11 IA en 13 Version 1 3 CA US Installation Manual SMA CONNECTION UNIT 1000 US...
Page 2: ......
Page 6: ...General Warnings SMA Solar Technology America LLC 6 CU1000 US 11 IA en 13 Installation Manual...
Page 44: ...www SMA Solar com SMA Solar Technology SMA Solar Technology America LLC www SMA America com...
