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Wiring Design and Protection Including Ground Fault Circuit Interrupters. Introduction.
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Wiring Design and ProtectionIncluding Ground Fault Circuit Interrupters
Introduction This material was produced under grant number SH-16615-07-60-F-12 from the Occupational Safety and Health Administration, U.S. Department of Labor. It does not necessarily reflect the views or policies of the U.S. Department of Labor, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government. This material was produced by the Workplace Safety Awareness Council, a 501(c)(3) not-for-profit organization dedicated to safety in the workplace. For further information about the council or upcoming safety related training, please visit our website at www.wpsac.orgor call us at (863) 537-4053.
Ground-Fault Circuit Interrupter • This device protects you from dangerous shock • If a ground fault is detected, the GFCI can shut off electricity flow in as little as 1/40 of a second, protecting you from a dangerous shock
Ground Fault Receptacles 1910.304(b)(3)(i) & (b)(3)(ii)(A) GFCI are required: • in bathrooms • on rooftops • temp wiring for maintenance, remodeling or repair • extension cords if used for temp. electric power • receptacles used for equipment in damp or wet locations
Outlet devices Outlets shall not be rated for less than the circuit load
Clearance for Overhead Lines 1910.304(c)(2) - Table S-6 Separation of Overhead Lines & Pedestrians Installations on or after August 13, 2007 10’ Clearance – less than 150V to ground Examples include: • Finished grade • Side walks
Clearance for Overhead Lines 1910.304(c)(2) - Table S-6 Separation of Overhead Lines & Vehicles / Equipment Installations on or after August 13, 2007 12’ Clearance – less than 300V to ground Examples include: • Residential property and driveways • Commercial area subject to vehicular traffic other than truck
Clearance for Overhead Lines 1910.304(c)(2) - Table S-6 Separation of Overhead Lines & Vehicles / Equipment Installations on or after August 13, 2007 15’ Clearance – 301V – 600V to ground Examples include: • Residential property and driveways • Commercial area subject to vehicular traffic other than truck
Clearance for Overhead Lines 1910.304(c)(2) - Table S-6 Separation of Overhead Lines & Vehicles / Equipment Installations on or after August 13, 2007 18’ Clearance – Less than 600V to ground Examples include: • Public streets, alleys, roads and driveways • Commercial area subject truck traffic • Other land traversed by vehicles (i.e. cultivating, forests)
Clearance From Building Openings 1910.304(c)(3)(i) • 3’ from windows, doors, porches, fire escapes, balconies etc. • Service conductors may not be below openings through which materials may be moved
Overcurrent Protection 1910.304(f)(1)(iv) – (ix) Overcurrent protection: • Readily accessible to building management personnel • Not be located where they could be damaged • Breakers clearly indicate whether on or off • If operated vertically up position is on • C.B. shall be marked SWD if used as switches • C.B. rated 120/240 used only on 120/240 circuit panels • C.B. rated 277/480 used only on 277/480 circuit panels
Appliances to be Grounded 1910.304(g)(6)(iii) & 1910.304(g)(6)(iv)(A) • Ranges, ovens, counter cooking units, clothes dryers if within 8’ vertically or 5’ horizontally of grounded objects • Hazardous locations • Supplied by metal clad, metal sheathed or metal raceway • Any terminal at over 150v to ground
Appliance Requirements 1910.305(j)(3)(ii) – (iii) Appliances • Shall have a disconnecting means • Shall have nameplate with rating in volts and amps or in volts and watts
Equipment Grounding 1910.304(g)(6)(vi)(C)(1) – (6) Equipment Shall be Grounded • Refrigerators, freezers, and air cond. • Clothes washer, dryer, dishwasher, sump pumps, aquarium equipment • Motor tools • Hedge clippers, lawn mowers, snow blowers, wet scrubbers • Appliances in wet locations • Portable X-ray • Portable hand lamps
Wiring System Prohibitions 1910.305(a)(1)(iii) No wiring system installed in ductwork used to transport dust, loose stock, flammable vapors, or ducts for commercial cooking equipment
Temporary Power & Lighting 1910.305(a)(2)(i)(B) • Temporary Power & Lighting not to exceed 90 days (i.e. Christmas lighting, carnivals, etc.) • This also includes experimental work and emergencies
General Wiring 1910.305(a)(2)(v)(C) General wiring • No branch – circuit conductors may be laid on the floor • All lamps for general illumination shall be protected • Flexible cords and cables shall be supported
Distinguishing Conductors 1910.305(f)(3) Conductors must be distinguished by color or other means • Grounded conductor • Ungrounded conductor • Grounding conductor
Motors 1910.305(j)(4)(i) Motors • Disconnecting means “within sight of” and not more than 50’ away • Disconnecting shall plainly indicate whether off or on • Disconnecting means shall be readily accessible
Transformer Vaults 1910.305(j)(5)(vii) – (viii) Transformer vaults • Any pipe or duct system foreign to the electrical installation may not enter or pass through the vault • Materials may not be stored in vaults
Amusement Rides 1910.306(k)(2)(ii) Amusement rides and attractions shall be not less than 15’ in any direction from overhead conductors of 600V or less. For conductors over 600V they cannot be below and within 15’