SMA Rapid Shutdown System

ID: prod:sma-rapid-shutdown-system
IRI: https://solarlattice.org/kb/prod/sma-rapid-shutdown-system
Status: active
Also known as: RSS-US-IA, PVRSS, PV Rapid Shutdown System
Category: MLPE
Make: sma
Product level: family

The SMA Rapid Shutdown System is a complete PV rapid shutdown setup. It is made up of an SMA inverter, PV module or array disconnect switches, and a rapid shutdown initiator. Together they must bring the DC conductors below 30 V within 30 seconds. The inverter on its own is listed as PV Rapid Shutdown Equipment under UL 1741 and does not perform every function of a complete system. The installer is responsible for making sure the finished system meets NEC rapid shutdown requirements. Rapid shutdown starts when the inverter loses AC grid voltage, for example when the main PV AC disconnect is opened. That disconnect must be readily accessible and marked, and its Off position shows that a shutdown has been initiated. With SunSpec-compliant module switches, the inverter sends a permission-to-operate signal over the DC conductors and stops sending it during a shutdown. Every module connected to the inverter must then have a SunSpec-compliant switch. The switches must disconnect the array within 15 seconds. The sum of switch standby voltages in a string must stay below 30 V, and newer manuals add a lower limit of 3.6 V. The recommended total string cable length is 300 m (1000 ft) on Sunny Tripower models and 160 m (520 ft) on Sunny Boy Smart Energy. On Sunny Boy Smart Energy, the initiator can be the AC disconnect or a device wired to the GSI digital input, such as the SMA Rapid Shutdown Initiator RSI-US-50, which can serve up to 3 inverters. SMA supports JMS-F SunSpec certified rapid shutdown devices. Each one should measure about 1 Vdc before it is connected into a string.

<!-- review notes

sentence 4: support check: partial - Signal, stop on shutdown and 15 s disconnect are stated, but 'every module must have a SunSpec switch' is stated as needed for proper function, fine; however the 15 s applies to all disconnect switches rather than only SunSpec ones, a minor qualifier.
sentence 5: support check: partial - The <30 V, >3.6 V in newer manual, 300 m and 160 m are stated, but the 160 m passage (u24) is for a different inverter (PV or hybrid) and Sunny Boy Smart Energy is not named there; u26 attributes it to the SBSE section only implicitly, and u26's 3.6 V/160 m is shown while u30 shows 300 m with 3.6 V too, so 'Sunny Tripower' attribution is unstated.
sentence 6: support check: partial - RSI-US-50 up to 3 inverters and a GSI digital input initiator option are stated, but 'AC disconnect' as an SBSE initiator option and the RSI wired to the GSI are only loosely supported. -->

Claims

`manufactured_by`

c1 drafted · lead SMA

sbsexx-us-50-rapid-shutdown-equipment sec=h1 h=fbcb8e01281b
STPxx-US-50-BE-en-14 sec=4.5.10 h=aea2d80fffb7

review note: support check: partial - Passages describe an SMA inverter-based rapid shutdown system (SMA 360° app, SMA Rapid Shutdown Initiator) but never state that the system is made by SMA explicitly; implied only.

`implements`

c2 drafted · lead PV rapid shutdown

A complete system is the SMA inverter (listed as PV Rapid Shutdown Equipment), PV array disconnect switches and a rapid shutdown initiator; it must bring DC conductors below 30 V within 30 seconds.

SMA STP 33-US IOM sec=h79 h=e0da560c67b6
sbsexx-us-50-rapid-shutdown-equipment sec=h1 h=fbcb8e01281b
STPxx-US-50-BE-en-14 sec=4.5.10 h=aea2d80fffb7
STP33-62-US-41-BA-en-13 sec=h76 h=f47c5bb7909c

`uses_protocol`

c3 drafted · lead SunSpec rapid shutdown signal

The inverter sends a SunSpec permission-to-operate signal over the DC input conductors and stops it when rapid shutdown is initiated.

SMA STP 33-US IOM sec=h79 h=e0da560c67b6
sbsexx-us-50-rapid-shutdown-equipment sec=h1 h=fbcb8e01281b
STPxx-US-50-BE-en-14 sec=4.5.10 h=aea2d80fffb7
STP33-62-US-41-BA-en-13 sec=h76 h=f47c5bb7909c

`requires`

c4 drafted · lead Qualified person

Connecting the external SMA Rapid Shutdown Initiator RSI-US-50 is a task for a qualified person.

SBSExx-US-50-BE-en-11 sec=h197 h=2164977aaec7

review note: support check: partial - u25 is headed QUALIFIED PERSON and covers connecting the RSI-US-50, but the passage doesn't explicitly say it requires a qualified person beyond the heading.

`compatible_with`

c5 drafted · lead Sunny Boy Smart Energy US-50

Rapid Shutdown function enabled by default on this inverter.

sbsexx-us-50-rapid-shutdown-equipment sec=h1 h=fbcb8e01281b
SBSExx-US-50-BE-en-11 sec=4.4.11 h=651fa43381de
sbsexx-us-50-sm-rapid-shutdown-initiator tbl=1 h=3f6455b58cd5

review note: support check: partial - u16 links RSI-US-50 to Sunny Boy Smart Energy, but the default-enabled note appears in u24/u26 whose applicability to SBSE US-50 isn't stated in the passages.

c6 drafted · lead Sunny Tripower CORE1-US

Rapid Shutdown function disabled by default.

SMA STP 33-US IOM sec=h79 h=e0da560c67b6
STP33-62-US-41-BA-en-13 sec=h76 h=f47c5bb7909c
stpxx-us-41-configuring-the-rapid-shutdown-function sec=front h=a658b65c6f8a

review note: support check: partial - Disabled-by-default is stated in u2/u34, and u7 is a Sunny Tripower CORE1-US configuration article, but u2/u34 don't name the product explicitly.

c7 drafted · lead Sunny Boy 3.0-7.7-US-41 proposed

sbx1xpus41-configuring-the-rapid-shutdown-function sec=front h=07476a4e5bca
SBxx-US-1XP-41-BA-en-12 tbl=19.r3 h=cbb2f6177c5f
sbx1xpus41-configuring-the-rapid-shutdown-function tbl=1.r3 h=d0088ff9ec26

review note: support check: partial - u4 is a Sunny Boy 3.0-7.7-US-41 configuring-rapid-shutdown article title, implying compatibility, but no content states it.

c8 drafted · lead Sunny Tripower TL-US

DC-side discharge is off by default and must be activated manually after commissioning.

STPTL-US-10-IA-xx-22 sec=h63 h=01288b4fa6a7

review note: support check: partial - u29 states DC discharge off by default and must be activated manually, but doesn't name Sunny Tripower TL-US or explicitly state compatibility.

c9 drafted · lead JMS-F rapid shutdown device proposed

SMA-compatible SunSpec certified rapid shutdown receiver mounted on each module frame.