690.15(C) Direct-Current Combiner Disconnects.

Even though the DC combiner box has the required disconnect, there is still another code violation. Can you spot it? This is an ungrounded PV system which is easily spotted because of the number of fuse holders. White conductor marking is only allowed on grounded conductors.
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Even though the DC combiner box has the required disconnect, there is still another code violation. Can you spot it? This is an ungrounded PV system which is easily spotted because of the number of fuse holders. White conductor marking is only allowed on grounded conductors.

Code Change Summary: A new code section now requires direct current combiner disconnects.

New requirements in 690.15(C) now specify that the DC output of DC combiners mounted on rooftops of dwellings and other buildings must have a load break rated disconnecting means either in the combiner box or within 6 ft. of the combiner.

This new rule allows first responders to quickly de-energize specific circuits in life safety emergencies or to make roof penetrations. Even though there are new rules on rapid shutdown in 690.12, there is no code language dictating where the rapid shutdown initiation device is to be located.

Having a load break disconnecting means within 6 ft. of a DC combiner located on the roof provides an additional measure of safety especially if the first responders cannot locate the rapid shutdown switch for the PV system conductors.

Below is a preview of the NEC®.  See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on the “free access” tab and select the applicable year of NFPA 70 (National Electrical code).

2014 Code Language:

690.15(C) Direct-Current Combiner Disconnects. The dc output of dc combiners mounted on roofs of dwellings or other buildings shall have a load break disconnecting means located in the combiner or within 1.8 m (6 ft) of the combiner. The disconnecting means shall be permitted to be remotely controlled but shall be manually operable locally when control power is not available.

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690.15(C) Direct-Current Combiner Disconnects.

Below is a Real Question from our Electrical Continuing Education Courses for Electrical License Renewal:

Which of the following is true of a DC combiner box in a PV installation?

A: DC source circuits inside the box must be separated from each other by a partition.
B: If mounted on the roof of a building it must have a load break rated disconnecting means integral to the combiner or within 6 ft.
C: The disconnecting means is NOT permitted to be remotely controlled.
D: If mounted at grade level it must have a load break rated disconnecting means integral to the combiner.
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