Electrical Safety and Safe Work Practices

Why Electrical Training?

What Problems Do You See in Your work area? Damaged plug Missing ground pin Shorted out – the missing prong was found still in the outlet... Why is a missing ground pin a problem? Missing ground pin: If there is any damage to the internal electrical wiring, the exterior of the equipment can become energized. The Ground provides a path back through the circuit breaker, that will cause the circuit breaker to trip. Without the ground pin, you risk becoming the path for the electricity...

What Problems Do You See in Your work area? Damaged GFCI outlet Why didn’t the GFCI prevent the damage? The GFCI device measures the current flow out on the hot lead, and returning on the neutral lead. They should be equal. If not, the GFCI trips. In this case, the short happened between the hot lead and the neutral lead, so the GFCI did not trip!

What Problems Do You See in Your work area? Spliced and taped cord on a lamp – fire and electrocution hazard

Don’t do this at home..... Not at BD – this picture is from the internet.

Home Electrical Safety Do not connect more than 3 light sets together & do not overload extension cords (use an outlet strip with built-in overload protection). Turn off all Christmas lights prior to leaving your home or going to bed. Test your smoke and carbon monoxide detectors, replace batteries. Plug lights & decorations into circuits protected by GFCIs (ground fault circuit interrupters). Never use lights with frayed cords, loose or bare wires, cracked or empty sockets. If outdoors, use only electrical decorations certified for outdoor use & keep clear from snow and water & use GFCI protected circuit. Use only equipment that is UL listed and in good repair.

Why Follow the Rules? Electrical shock Arc Flash hazard What is the highest voltage on production equipment here at BD – Sandy? When was the last electrical shock incident (other than static electricity) at BD – Sandy? Arc Flash hazard Electrical fires Electrical burns Highest Voltage on Production Equipment: UV Cure lamp electrical circuit: 11,500 Volts Last Electrical Shock incident: That I know of, October 2008...

ELECTRICAL HAZARDS Misnomer: Electricity flows through the path of least resistance. (It flows through ALL paths…) Electric shock occurs when the human body becomes part of the path through which electrical current flows. The direct result can be electrocution. Burns can result when a person touches electrical wiring or equipment that is energized The indirect result can be injury resulting from a fall or movement into machinery because of a shock.

Arc Flash/ Arc Blast Occurs when high amperage current jumps a gap (short circuit) – such as when un-insulated tools are being used on live electrical circuits... Arc Flash / Arc Blast injuries was the number one source of electrical injuries, and has been for many years… An arc blast can occur when electrical cabinets/panels are open Temperatures can be as high as 35,000 F Metal, Molten metal, or other objects Pressure Wave

ELECTRICAL HAZARDS Explosions: Occur when electricity provides an ignition source for an explosive mixture in the air. Flammable vapors Dust (plastic dusts, grain dust, other organic material, metal dusts,etc) Fires: Electricity is the most common cause of fires both in the home and in the workplace. Defective or misused electrical equipment is a major cause. Electrically Classified Areas and Equipment: Never substitute parts, never make modifications without an Engineering Review!

ELECTRIC SHOCK Effects of electric shock depend on: -- Current & voltage -- Resistance -- Path through body -- Duration of shock

CURRENT & VOLTAGE As alternating current increases: Tingling gives way to muscle contractions Pain develops Control of muscles becomes increasingly difficult At 15 mA, victims cannot let go of the conductive surface At 70 mA, ventricular fibrillation of the heart occurs (a typical circuit is 15 amps plus) Death follows in a few minutes Heavy current flow can also result in severe burns (internal & external) & heart paralysis

BY-STANDERS AND APPROACH DISTANCES (AKA Electric Shock Protection Boundaries) Nominal System Voltage Range, Phase to Phase Limited Approach Boundary Restricted Approach Boundary Prohibited Approach Boundary Exposed Movable Conductor  Exposed Fixed Circuit Part  Less than 50  36 in Avoid Contact 50-300  10 ft 0 in 3 ft 6 in Avoid contact 301-750  1 ft 0 in 1 in   751-15 kV  5 ft 0 in 2 ft 2 in 7 in 15.1 kV-36 kV  6 ft 0 in 2 ft 7 in 10 in 36.1 kV-46 kV  8 ft 0 in 2 ft 9 in 1 ft 5 in

General Electrical Concerns Extension cords can be made ONLY by “Qualified Individuals” (see above…) Do not use gang plugs (wall mount box on end of extension cord with 2 or more outlets installed…) Do not use cords with broken ground prongs Do not piggy-back surge protectors Do not use zip cords (light weight household type extension cords that do not have a secondary insulation sheath)

General Electrical Concerns Keep all electrical equipment clear from water and moisture Building Circuit Breakers can be reset ONLY by Qualified Facilities Personnel The only persons authorized to open and do any work in an electrical cabinet on production equipment are: Qualified Electro-mechanics Qualified Engineers

Don’t do this at Home....

Contact Info Ron Ruiz Rruiz3@slcc.edu