ECN Forum Forums General Topics of the Trade Alternative Energy New Jersey Warehouse Fire 9-1-13 Caused by PV?

Isn't the 2014 NEC going to require a "quick disconnect" for all new PV systems? I thought that I read it somewhere.

Hi Harold...this is from the 2014 NEC draft...

690.12 PV Arrays on Buildings Response to Emergency
Shutdown. . For PV Systems installed on roofs of buildings,
photovoltaic source circuits shall be deenergized from
all sources within 10 seconds of when emergency shutdown
is initiated or when the PV power source disconnecting
means is opened. When the source circuits are deenergized,
the maximum voltage at the module and module conductors
shall be 80 volts.

And here is a link to a piece of equipment that will do the job...

http://www.solarbos.com/products/combiner-boxes/contactor-combiners

shortcircuit

80 volts max? That gonna run costs up. More circuits bigger wire. It's good thing I'm not planning putting my systems of roofs. Most if not all of my systems are exceed 80 volts at the modules

This is 2014 NEC 690.12 from the softbound PDF:

690.12 Rapid Shutdown of PV Systems on Buildings.
PV system circuits installed on or in buildings shall include
a rapid shutdown function that controls specific conductors
in accordance with 690.12(1) through (5) as follows.
(1) Requirements for controlled conductors shall apply
only to PV system conductors of more than 1.5 m (5 ft)
in length inside a building, or more than 3 m (10 ft)
from a PV array.
(2) Controlled conductors shall be limited to not more than
30 volts and 240 volt-amperes within 10 seconds of
rapid shutdown initiation.
(3) Voltage and power shall be measured between any two
conductors and between any conductor and ground.
(4) The rapid shutdown initiation methods shall be labeled
in accordance with 690.56(B).
(5) Equipment that performs the rapid shutdown shall be
listed and identified.

I have a lot of reading to do, starting thru the NFPA version of the '14 Changes.

So the 5 and 10 foot rule is how the book reads? I have seen both proposals...but have not bought a 2014 NEC yet...

I have the '14 NFPA version with te PDF, and the Changes package.

Could not get it thru Mr Bill, as the PDF is 'NFPA Only'

I really miss the CD/DVD formats, but it seems they are gone by the wayside since '08

Shortcircuit,

That quick disconnect looks very nice. I always thought that there should be a way of disconnecting the current coming down from the roof without having to climb up there.

This new quick disconnect will only have to be installed on the full DC type systems where the send the DC down from the roof to the inverters right?

If the system on the roof has the micro inverters, would the quick disconnect be required? After all if you interrupt the AC going up to the roof, the inverter stops the current right there at the solar panel.

Yes on the DC systems with photovoltaic output circuits leaving the array. The large arrays on rooftops will probably have many of the shunt trip combiner boxes.

With the micro inverter systems when the AC is shut down, it kills the power right to the individual panel. The micro inverter systems are a best choice for fire fighters.