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Roof disco
- Thread starter SAP
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Ask for a code reference on why you need the disco
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Fresno has a municipal code that requires a DC disconnect, not AC. A few of the surrounding AHJs have adopted a similar stance. Moving forward, you should be able to sit down with the fire official and explain that the new requirements for rapid shutdown (micro-inverters are compliant) preclude the need for a handled box on the roof.
FYI - the relevant language is buried in Chapter 10:
605.11.3. DC Roof Top Disconnects. There shall be a separate emergency DC disconnect on the roof to disconnect solar panels from DC wiring running through, and on, the building to the inverter. This disconnect must be permanently labeled in reflective, fade-resistant material that states: "Emergency DC Disconnect." Disconnects, shall be in a NEMA 3R box, and shall be installed as close to the array as possible to reduce the length of energized wiring that cannot be shut down. Commercial installation where multiple disconnects are required will be evaluated for approval on a case by case basis by the fire code official or designee.
There were many local attempts to add emergency shutdown to the PV array in years past. There was an AHJ in Temecula CA that was requiring a remote operated DC contactor on the roof and this was maybe 7 or 8 years ago. Now that RSS is in the code all these local attempts to introduce array isolation need to be removed but guess who needs to do that? Local PV installers need to push for it when the local versions of codes are updated.
There were many local attempts to add emergency shutdown to the PV array in years past. There was an AHJ in Temecula CA that was requiring a remote operated DC contactor on the roof and this was maybe 7 or 8 years ago. Now that RSS is in the code all these local attempts to introduce array isolation need to be removed but guess who needs to do that? Local PV installers need to push for it when the local versions of codes are updated.
In the case of Fresno, the ordinance was snuck in with other changes to the fire code. No justification was provided pursuant to state law, I'm honestly not sure why no one called them out on that.
In the case of Fresno, the ordinance was snuck in with other changes to the fire code. No justification was provided pursuant to state law, I'm honestly not sure why no one called them out on that.
On the national level there are a lot of people looking for electrical requirements, particularly PV, sneaking into non-electrical codes. It's a lot of work and requires lots of people monitoring different code making processes. There is just not the same thing in place to catch every local code modification. It's up to people in a local jurisdiction to watch for that kind of thing.
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