Installing a solar PV system is a great way to take control of your energy sources. However, it is important to ensure that your system meets code requirements, including the one around the rapid shutdown of PV systems.

Trinaswitch from Trina Solar adds smart functionality to solar modules, allowing you to shutdown your system at a moment’s notice. Additionally, a Trinaswitch system can be upgraded to Trinasmart, which lets you lower the balance of system (BOS) cost and increase panel design flexibility. It also ensures your system complies with the updated safety precautions outlined in the National Electrical Code (NEC).

Following NEC requirements

The National Fire Protection Association, a private trade association, establishes the guidelines for electrical safety in residential, commercial and industrial buildings, with its comprehensive NEC. This standards book covers regulations on:

• Installation of equipment
• Electrical wiring
• Over current protection
• Grounding
• Safety precautions

The NEC continues to update and add rules. This is especially true of rules around local power generation, reflecting the continued growth in renewable power technology, including solar panels. To further address safety best practices for the installation and operation of solar PV systems, the NFPA in 2014 added rule 690.12, "Rapid Shutdown of PV Systems on Buildings."

Why is rapid shutdown important?

This rule establishes requirements designed to mitigate electrical and fire safety hazards, particularly for first responders. The NFPA set up these rules to provide a national framework for solar PV safety, just like they do for any electrical system in a home or office, such as the wiring or lighting. This ensures that first responders in the thousands of jurisdictions across the country can all follow the same best practices. 

The rapid shutdown requirements are in place because a PV system’s conductors may still remain energized even after the inverter is turned off, according to Solar Power World. This poses dangers to first responders who might have to interact with the system.

The rapid shutdown rule requires systems have the means to limit the voltage in conductors of a PV system to 80 V. Trinaswitch accomplishes this goal by stopping current produced by the PV system at the module junction box as soon as the system is disconnected from AC power.

Currently more than 24 states require that all rooftop solar modules comply with this standard, and more states are expected to follow suit. However, as noted by Homepower, the rule doesn't specify a single "rapid shutdown initiation device" or strategy. While there might be several different ways to implement this task, not all of them come with a full range of value-added functionalities that ultimately reduce costs to end users.

An inexpensive option for rapid shutdown 

Trinaswitch, a cost-effective safety solution for solar PV modules, meets the NEC 690.12 module-level rapid shutdown requirements. If the PV system is disconnected from the inverter or in the case of AC power loss, Trinaswitch has module-level disconnect to remotely deactivate the module, mitigating safety hazards. 

The smart module also monitors your PV module parameters around the clock, providing real-time data on module performance. If the smart module detects a safety hazard, such as over-heating or over-voltage it will enter PV-Safe mode and send a report to the Cloud Connect. If necessary, the system will perform an automatic rapid shutdown of a single module or the entire array.

Not only does Trinaswitch give you ultimate control over your solar PV array, it's the only system with upgradeable functionality. You can swap out the junction box faceplate to upgrade a Trinaswitch module to Trinasmart, which has module level optimization and a capped maximum voltage. This allows for more flexibility in how you design your system. You can potentially add more modules, thereby generating more power and obtaining a faster return on investment.

With increased system safety and reduced BOS cost potential, Trinaswitch makes the best financial sense for the rapid shutdown of solar PV systems.

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