SMA SUNNY TRIPOWER STP DC CONNECTION UNIT - COMBINER BOX WITH DC DISCONNECT, CU 1000-US-10

Features

SMA Sunny Tripower STP DC Connection Unit – Combiner Box with DC Disconnect, CU 1000-US-10

The Connection Unit is an optional system component of the Sunny Tripower TL-US production series and includes Combiner Box and disconnect functionality in one convenient enclosure. Its integrated reverse polarity indicator supports safe installation.

The Connection Unit is a String-Combiner to which up to eight strings can be connected.

In the Connection Unit the PV array strings are combined and routed into the inverter via cables. The
integrated fuse holders are designed to be used with string fuses for overcurrent protection. The Connection Unit is equipped with a DC switch-disconnector and therefore serves as a DC disconnection unit.

The Connection Unit is equipped with a DC switch-disconnector. The DC switch-disconnector enables
disconnection of the inverter from the PV array. The disconnection takes place at all poles.

The Connection Unit is suitable for indoor and outdoor use.
The Connection Unit must only be used in ungrounded PV systems. Do not use grounded PV modules
with the Connection Unit. Only ground the mounting frame of the PV modules.
All DC inputs of an ungrounded PV system must be equipped with an overcurrent protection
according to the National Electrical Code® NEC 690. The Connection Unit shall be installed per the
requirements contained in Section690.35 of the National Electrical Code®, ANSI/NFPA 70. The
Connection Unit must only be used with the following transformerless SMA inverters:
• SB 6000TLUS-12 / 7000TLUS-12 / 8000TLUS-12 / 9000TLUS-12 / 10000TLUS-12 / 11000TLUS-12
• STP 12000TL-US-10 / 15000TL-US-10 / 20000TL-US-10 / 24000TL-US-10

String fuses are used to protect wiring and equipment from excessive currents that can cause damage, heating, or in extreme cases, even fire.
If the string fuses are designed too small, they may open too early and cause interference. If the string fuses are designed too large, they do not provide the required protection as they open too late.
In PV systems, the minimum and maximum size of the string fuse is determined by the electrical nominal sizes of the PV module as well as by UL and National Electrical Code® requirements. Contact the manufacturer of the PV modules in order to obtain the corresponding nominal sizes of the string fuses.
The maximum nominal size for string fuses in the Connection Unit is 20 A

The minimum size of the string fuses and cables is calculated by means of the short-circuit current rating (ISC) of the PV module. The National Electrical Code® stipulates that all string fuses and cables are designed to be at least 1.56 times as large as the Isc of the PV module being used. The correct size of the string fuse is determined by calculating the minimum size and then rounding it up to the nearest standard size for string fuses.

Example: calculating the minimum size of the string fuses
For example, if the Isc of the PV module equals 6.9 A, then the size of the string fuses is determined as follows: 1.56 x 6.9 = 10.76
The nearest standard size for string fuses would be a 12 A fuse.

The SMA Connection Unit 1000-US is equipped with reverse polarity detection.

The reverse polarity detection will test if the polarity of the connected conductors is correct once a string has been newly connected. Testing occurs by operating the integrated button. As long as there is sufficient DC voltage, the test result is visualized by the LEDs flashing.