Wiring Design and Protection Including Ground Fault Circuit Interrupters

This material was produced under grant number SH 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 or call us at (863) Introduction

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 (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

Separation of Overhead Lines & Pedestrians Installations on or after August 13, ’ Clearance – less than 150V to ground Examples include: Finished grade Side walks Clearance for Overhead Lines (c)(2) - Table S-6

Clearance for Overhead Lines (c)(2) - Table S-6 Separation of Overhead Lines & Vehicles / Equipment Installations on or after August 13, ’ 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 (c)(2) - Table S-6 Separation of Overhead Lines & Vehicles / Equipment Installations on or after August 13, ’ Clearance – 301V – 600V to ground Examples include:  Residential property and driveways  Commercial area subject to vehicular traffic other than truck

Clearance for Overhead Lines (c)(2) - Table S-6 Separation of Overhead Lines & Vehicles / Equipment Installations on or after August 13, ’ 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)

3’ from windows, doors, porches, fire escapes, balconies etc. Service conductors may not be below openings through which materials may be moved Clearance From Building Openings (c)(3)(i)

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 Overcurrent Protection (f)(1)(iv) – (ix)

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 Appliances to be Grounded (g)(6)(iii) & (g)(6)(iv)(A)

Appliances Shall have a disconnecting means Shall have nameplate with rating in volts and amps or in volts and watts Appliance Requirements (j)(3)(ii) – (iii)

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 Equipment Grounding (g)(6)(vi)(C)(1) – (6)

Wiring System Prohibitions (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 not to exceed 90 days (i.e. Christmas lighting, carnivals, etc.) This also includes experimental work and emergencies Temporary Power & Lighting (a)(2)(i)(B)

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 General Wiring (a)(2)(v)(C)

Conductors must be distinguished by color or other means  Grounded conductor  Ungrounded conductor  Grounding conductor Distinguishing Conductors (f)(3)

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 Motors (j)(4)(i)

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 Transformer Vaults (j)(5)(vii) – (viii)

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’ Amusement Rides (k)(2)(ii)