Page 121 - Solar Power in Building Design The Engineer's Complete Design Resource

ELECTRIC SHOCK HAZARD AND SAFETY CONSIDERATIONS 91

methodology are subject to rigorous guidelines, which are outlined in the National
Electrical Code (NEC) Article 690.
System components, such as overcurrent devices, breakers, disconnect switch-
es, and enclosures, are specifically rated for the application. All equipment that is
subject to maintenance and repair is marked with special caution and safety warn-
ing tags to prevent inadvertent exposure to hazards (see Appendix B for typical
sign details).

SHOCK HAZARD TO FIREFIGHTERS
An important safety provision, which has been overlooked in the past, is collaborating
with local fire departments when designing roof-mount solar power systems on wood
structures. In the event of a fire, the possibility of a serious shock hazard to firefight-
ers will exist in instances when roof penetration becomes necessary.

SAFETY INSTRUCTIONS

■ Do not attempt to service any portion of the PV system unless you understand the
electrical operation and are fully qualified to do so.
■ Use modules for their intended purpose only. Follow all the module manufacturer’s
instructions. Do not disassemble modules or remove any part installed by the
manufacturer.
■ Do not attempt to open the diode housing or junction box located on the back side
of any factory-wired modules.
■ Do not use modules in systems that can exceed 600 V open circuit.
■ Do not connect or disconnect a module unless the array string is open or all the
modules in the series string are covered with nontransparent material.
■ Do not install during rainy or windy days.
■ Do not drop or allow objects to fall on the PV module.
■ Do not stand or step on modules.
■ Do not work on PV modules when they are wet. Keep in mind that wet modules
when cracked or broken can expose maintenance personnel to very high voltages.
■ Do not attempt to remove snow or ice from modules.
■ Do not direct artificially concentrated sunlight on modules.
■ Do not wear jewelry when working on modules.
■ Avoid working alone while performing field inspection or repair.
■ Wear suitable eye protection goggles and insulating gloves rated at 1000 V.
■ Do not touch terminals while modules are exposed to light without wearing elec-
trically insulated gloves.
■ Always have a fire extinguisher, a first-aid kit, and a hook or cane available when
performing work around energized equipment.
■ Do not install modules where flammable gases or vapors are present.