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Complying with USA National Electric Code (NEC) 690.12 Rapid Shutdown

  • Updated

Tigo is pleased to announce that its TS4-S, TS4-O, TS4-L, and junction box equivalent products, along with the TS4-F and 2F PLC signaling controlled models - provide a solution to USA National Electric Code  (NEC) revisions of 2014 and 2017 defined in section 690.12 requirements for Rapid Shutdown System (RSS) - assuming all the following requirements are met:

For NEC 2014 Compliance

  • All modules are equipped with either one or a combination of the following TS4 units:
    • TS4-S/TS4-A-S (Safety models)
    • TS4-O/TS4-A-O (Optimizing models)
    • TS4-L/TS4-A-L (Optimizing with voltage limiting models)

or

    • TS4-F/TS4-A-F (Fire Safety models, only. Can not be combined with O, S, or L)

or

    • All modules are Smart Modules (TS4-S/O/L) which are Integrated MLPE installed at PV module factory. They use the JES or HBF integrated junction box.

Along with:

  1. For O/L/S models: a Cloud Connect or Cloud Connect Advanced and 1 or more TAP(s)  (or Gateways) or, for F models: a compatible RSS PLC signaling Transmitter, either Tigo Energy or inverter integrated.
  2. The Cloud Connect Advanced or the RSS Transmitter(s) are powered by the same AC Grid Power as the  rapid-shutdown ready inverter
    • (For non-RSS ready inverters, DC disconnect must also be switched off to enter Rapid Shutdown)

A Photo  Voltaic  (PV) solar electric power system meeting the above criteria will initiate rapid shutdown that is compliant with NEC 2014 requirements when its main breaker is turned off which causes the outputs of all Tigo MLPE outputs to drop to 0 Amps and 0 Volts within 30 seconds. Thus, array voltage is below 30V and 240V AC inside the PV Module Array boundaries as required by NEC 2014 version codes.

These solutions were tested and certified by Intertek in October 2014.

For NEC 2017 Compliance

Per NEC 2017 690.12, the requirements below will be mandated as of January 2019. Until that date, either the solution above for NEC 2014 or the solution below for NEC 2017 are acceptable.

The requirements mandated as of January 2019:

  • All modules are equipped with either TS4-S/TS4-A-S or TS4-O/TS4-A-O with CCA and TAP, or TS4-F/TS4-A-F with RSS PLC signaling transmitter.
  • The CCA/RSS Transmitter(s) are installed on the same power company AC service main circuit breaker as a rapid-shutdown ready inverter
    • For non-RSS ready inverters, make sure that upon AC Grid Power loss the inverter drops voltage between (+) and (-) string wires, and to Ground, within 30 seconds.
  • Installed inverter and Tigo TS4 products to be used are tested and certified by UL on the following website: http://productspec.ul.com/document.php?id=QIJS.E469960.

A PV system meeting the above criteria will initiate a Rapid Shutdown that is compliant with NEC 2017 requirements when its AC solar disconnect is turned off, causing the outputs of all module leads to drop to 0 Amps and 0 Volts - within 30 seconds. Thus, within the array (up to 1 ft or 305 mm from it) voltage drops below 80V, and outside the array, voltage drops below 30V, within 30 seconds, as defined by code.

 

Please consult the Tigo Energy Installation and Safety Manual to ensure that the system is set up and configured properly.

Click here to view our rapid shutdown certificates.

For the full details of rapid shutdown and other safety functions with Tigo PV-Safe, click here.

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