be obstructed by tree limbs, mechanical equipment, or other equipment or wires.
Workers need to observe access and spacing requirements, including those that:
Ensure access to the roof
Grant clear paths to particular spaces on the roof
Do not interfere with aeration for smoke ventilation
Allow emergency exits
Local authorities may have different requirements than those above. Condi-
tions for access, pathways, or ventilation may include the following:
Proximity and type of nearby exposures
Other access opportunities
Access to roof from the ground
Solar array ventilation
Other aeration prospects
Automatic ventilation device
New technology or methods that make access safe and easy for
fire departments
Residential Systems—Single-and Two-Unit Residential Dwellings
It is advisable to examine the local, state, and national requirements for residen-
tial access, pathways, and smoke ventilation. Many in the fire protection industry
recommend that PV systems taking up more than 50 percent of the roof area be
reviewed. This review will look at access, pathways, and smoke ventilation. The
following information comes from the California Department of Forestry and
Fire Protections Solar Photovoltaic (PV) Installation Guideline.
Access
Homes with hip roof layouts should have modules with at least one clear access
pathway that is three feet wide. Place this pathway at a bearing wall. Bearing walls
are structurally strong enough for this.
CODE
NEC 2011, 690.14(C)(2)
Marking. Each photovoltaic system disconnecting means shall be permanently marked to iden-
tify it as a photovoltaic system disconnect.
Reprinted with permission from NFPA 70
®
, National Electrical Code
®
, Copyright© 2010, National Fire
Protection Association, Quincy, MA.
36 ADVANCED PHOTOVOLTAIC INSTALLATIONS

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