Module 3

An ____ flash occurs when a flashover of electric current leaves the intended path and travels through the air from one conductor to another, or to ground

Arc

Grounding

- grounding creates a low-resistance path from a tool to the earth to dispense unwanted current - you should inspect electrical systems to ensure that the path to ground is continuous - you should ground exposed metal parts of equipment - don't remove ground prongs from tools or extension cords - Tools plugged into improperly grounded circuits may become energized

Fall Protection Preparation

1. Develop a written fall protection plan and train employees in fall protection safety 2. Assess potential fall hazards prior to each project 3. Use administrative controls to eliminate hazards by changing or rescheduling tasks 4. Inspect fall protection equipment to ensure its condition and appropriateness 5. Before starting work, remind employees of specific fall hazards that are present on the job site 6. Once work has begun, observe workers to ensure that fall protection equipment is being used properly

Electrical: Safety and Hazards

1. Energized Electrical Work Permit: energized work must be done because de-energizing would be riskier 2. Flame-resistant clothing and Class E hardhat: Joe may encounter falling objects and high voltages when he's within the Flash Protection Boundary 3. Rubber insulating gloves and hoods: Lisa will have to work near wires with a potential live electrical charge 4. Lockout/tagout: Jose will be inspecting and repairing electrical equipment 5. Special insulated tools: Steve will be working on fuses with energized teminals

Numbers to Remember

1. Guardrail systems must be able to withstand a force of at least 200 lbs at any point along the top edge 2. For pipe railings, posts shall be spaced not more than 8 feet apart on centers 3. A safety net's maximum mesh openings must not be longer than 6 inches on any side 4. Top rails must be 42 inches, plus or minus 3 inches, above the walking/working level 5. Intermediate members such as balusters, when used between posts, shall not be more than 19 inches apart 6. Safety net drop-tests must consist of a 400 lbs bag of sand being dropped into the net. 7. Safety net systems must be no more than 30 feet below the working surface 8. If safety nets are connected together, the connection must be as strong as the individual nets and not more than 6 inches apart 9. A Personal Fall Arrest System (PFAS) must be rigged so that an employee can neither free-fall more than 6 feet, nor contact any lower level

You're in charge of a new construction work site. You must make sure no one gets hurt and that everything complies with OSHA

1. Inspect the jobsite and work surfaces for hazards. 2. Determine that the work surfaces are strong enough to support the workers. 3. You find that work must be done near an unprotected edge 11 feet above lower levels, so workers need fall protection. 4. Have guardrail systems constructed and inspected. 5. Select and inspect the correct personal fall arrest systems, and make sure workers know how to use them. 6. Begin work and ensure workers follow safe work procedures.

What is the preferred setback distance from overhead wires during cleanup?

10 Feet

Electricity caused ___ percent of young worker deaths in the workplace.

12%

Positioning devices shall be secured to an anchorage capable of supporting at least twice the potential impact load on an employee's fall or ____ pounds, whichever is greater

3000 pounds

Toe boards shall be capable of withstanding, without failure, a force of at least ____ applied in any downward or outward direction at any point along the toeboard

50 pounds

Warning lines must be flagged at not more than ____ foot intervals with high-visibility materials

6

OSHA estimates that ____ of struck-by fatalities involve heavy equipment like trucks or cranes

75%

The area where the work space is located is called?

Activity Area

An ____ is received when electrical current passes through the body

Electric shock

Electrical current is the flow of _____ from a voltage source and back to the source

Electrons

How does electricity work?

Electrons flow from a voltage source through a conductor and back to the source

Electrical Safety Practices

Exposed Parts - screens that prevent contact, put eight feet or more above the floor, restricted room or platform Power Lines - stay at least ten feet away, never touch if downed, use wood or fiberglass ladders instead of metal ladders Cord and Wires - Remove by pulling on the plug, strain relief, marked for hard or extra-hard usage

A positioning device system is a fall arrest system

False

It is good practice to have the work zone area open to the public.

False

It is ok to use extension cords that have loose instillation and have exposed wires

False

Positioning devices shall be rigged such that an employee cannot free fall more than 6 feet

False, "Two feet"

_____ are overcurrent protective devices with a circuit opening fusible part that is heated and severed by the passage of overcurrent through that part

Fuses

Electrical Protective Devices

GFCIs - de-energizes a circuit in 1/40th of a second when a current to ground exceeds a predetermined value. Detects differences in current as small as 4 mA between the black and white wires. Fuses - circuit-opening fusible part is heated and severed by the passage of overcurrent through that part CBs - currents can be reset under certain abnormal circuit conditions such as those of a short circuit. Opens and closes a circuit without damage to the device when properly applied within its rating

Electrical review

Incident Energy - current travels through free air and the effects of the energy are not contained Arc Flash Incident - concentrated radiant energy explodes outward from electrical equipment, creating pressure waves

All covers should have any of the following to provide warning of a hazard except:

Inlabelled

The construction manager should have a daily ____ of the integrity of the equipment that is on the construction site.

Inspection

_____ debris left on a roof could easily be blown and strike a worker

Loose

Electrical protective devices are designed to automatically _____ a circuit, if excess current from overload or ground-fault is detected

Open

The revenue required for funds to offset an injury are:

Revenue Required = Total Cost of Incident / Profit Margin

_____ are used to connect lanyards to D-rings on a body harness

Snap hooks

Shock Severity

The severity of the shock depends of the path of the current through the body. amount of current flowing through the body(amps), and duration of the shocking current through the body

All profits are derived after the operational cost of the company have been calculated

True

IF working in damp locations, inspect electric cords and equipment to ensure that they are in good condition and free of defects, use a ground-fault circuit interrupter (GFCI)

True

If vehicular safety practices are not followed at a work site, workers are at risk of being struck-by swinging equipment

True

Proper safeguards should be used for all jacks and equipment.

True

The worker must never place their body between the tracks and the super structure of the crane. Though it is the closest area to communicate with the driver, this is an extremely dangerous practice.

True

Covers located in roadways and vehicular aisles shall be capable of supporting, without failure, at least ____ the maximum axle load of the largest vehicle expected to cross over the cover

Two times

Examples of indirect costs are:

Wages paid to injured workers, overtime due to the accident, training for replacement worker

The OSHA Construction requirement of 1926.1424 requires the creation of an area called ____ to protect workers from a Swing Radius Hazard

Work Area Control

Locking out and Tagging out of Circuits

1. Apply locks to the power source after de-energizing 2. Verify circuit is de-energized by testing with known functioning meters 3. Tag deactivated controls and power sources 4. Tag de-energized equipment and circuits at all points where they can be energized 5. Tags must identify equipment or circuits being worked on

Guarding of portable power tools and bench tools often have guards taken off for reasons that are _____ driven

Behavioral

Anyone of the job site can inspect powder actuated tools before they are used

False

It isn't a big deal to work underneath a suspended load.

False

How do you get an electrical shock?

Parts of your body completing an electrical circuit

Safe Practices

Personal Fall Arrest System - There is a hoisting area without guardrails Equipment Guards - Workers are working four feet above paving equipment Fences - An eight-foot-deep hole is hidden by overgrown grasses. Warning Line and Safety Monitoring Systems - Roofers are working on low-slope roofs with unprotected sides Hardhats and Barricades - Workers may be hit by falling tools and materials

A company's profit margin is calculated by:

Profit Margin = Total Profits / Total Sales

Each employee working in a controlled access zone must be directed to comply with all instructions by the _____

Safety monitor

If an overhead wire falls on your vehicle, then you should:

Stay in the vehicle

Always wearing bright, highly visible clothing when working near equipment is a method to avoid a _____ accident

Struck-by

Which device is strong but not flexible (absorbs little force)

Synthetic Webbing

What is the area in the MUTCD that is used to channel the motorists to the open travel lane.

Transition Area

_____ cost is no paid by the insurance company and is unrecoverable

Indirect

Workers that have to guide a load in anyway must not use their own hands on the load, but an approval tag line or guide line.

True