SAFETY TIPS - Electrical safety

The ABC's of Electricity

Current:

ç    Like water, electricity flows. It can flow through you and other conductors, such as metals.

ç    It can seriously harm you when it flows through your body (electric shock).

ç    The unit of current is the ampere (amp).

Resistance:

ç    Like the pipe restricts the water, resistance can restrict the current.

ç    The more resistance, the less the current flows.

ç    The unit of resistance is called an ohm.

Voltage:

ç    Like water hitting you, voltage is a force.

ç    The more water and faster it comes at you, the larger the force.

ç    The more current and less resistance means a bigger force.

ç    The unit of voltage is called a volt: (e.g. 440 volts)

Potential:

ç    When water is in a water tower, is has potential to drop and exert a force.

ç    Stored electricity can have a potential to move and exert a force.

ç    Capacitors are an example of stored electricity.

 

What Are The Causes of Electrical Accidents?

3 Basic causes:

1) Unsafe Acts by People

There are 2 basic reasons for unsafe acts:

1. We know better, but intentionally do something unsafe.

2. We don't know any better.

 

AVOID the following unsafe acts:

ç    Attempting to work on electrical equipment or components you are not trained for.

ç    Failure to de-energize, lockout & tag out hazards during maintenance, repair or inspections.

ç    Not verifying the power is off when making repairs

ç    Use of defective and/or unsafe tools, equipment, or instruments.

ç    Use of tools or equipment too close to energized parts.

ç    Not draining off stored energy in capacitors.

ç    Using a 3-wire cord with a 2-wire plug.

ç    Remove the wrong fuse.

 

2) Hazardous Environments

Be sure to use special precautions around hazardous conditions, such as:

ç    Flammable vapors, liquids and gases

ç    Combustible dusts

3) Unsafe Equipment

ç    Loose connections

ç    Faulty insulation

ç    Improper grounding

ç    Defective parts, such as broken cover plates

ç    Ground faults in equipment

ç    Unguarded live parts

Report all unsafe electrical equipment immediately so it can be repaired.

 

Electricity and How it Can Harm You

Effects on your body

A small night-light with a 6-watt bulb draws 0.05 ampere (50 milli amp), and even that small amount of current can be fatal. Here are some effects of current in milli amps (1/1000 of an amp) passing through a 150 pound (67.5 kg) body:

Milli Amps

 Perception 0.5 - 1.5

 Muscle contractions 1 –5

 Pain 3 – 10

 Let-go threshold 10 – 40

 Respiratory paralysis 30 – 75

 Ventricular fibrillation 75 – 100

 Heart paralysis 250 – 300

 Internal Organ burns 5000 – 6000

 

Current passing through your body can cause Electric Shock, resulting in 3 types of potential injuries:

1. Burns (arcs burn with heat & radiation)

2. Physical injuries (broken bones, falls, & muscle damage)

3. At 10 mA, the muscles clamp on to whatever the person is holding.

 Nervous system effects (breathing is stopped at 30 to 75 mA alternating current at 60Hz, fibrillation at 75 to 100 mA at 60Hz).  Fibrillation = heart "twitching" and there is no blood flow to the body.

 

The heart can be damaged because it is in the path of most common pathways:

 Hand to hand

 Hand to foot

 

First Aid for Electrical Shocks:

 

• Do not touch the casualty while he is still in contact with electricity.
• Switch off the current at once.
• Do not attempt first aid until the contact has been broken.
• Make the air passage clear and clean.
• Restore breathing Artificial respiration and external cardiac massage, if needed. (For External Cardiac Massage the first aider should be trained.)
• Call for immediate medical aid.

 

 

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Subject: SAFETY TIPS - Electrical safety

 

Electrical Safety

 

Electricity is an important part of our lives that cannot be taken for granted. Electricity must be treated with caution and respect.

 

 Practice safety precautions and these following tips to remain safe:

• Never go near or touch power lines. Assume every wire is "live" and never assume a line is "dead."
• Be cautious of downed wires. If you happen to come across downed wires, call the National Electric Service (NES). Keep people and pets away from the wire until the NES or police arrive.
• Do not fly kites, balloons or model airplanes near power lines. If one gets caught in a line, do not try to remove it. Leave it alone.
• Never install a TV or radio antenna within falling distance of power lines.
• Before you move a metal ladder or scaffolding, check to see that it's clear of power lines. They can be deadly if contact occurs with a line.
• Never climb trees, poles, or steel towers whose upper branches are contacting, or even near power lines.
• Never use water on electrical fires. Have everyone leave the house and call the fire department if you cannot extinguish it. If the fire is a small appliance, unplug the appliance or turn off the electricity. DO NOT TOUCH APPLIANCES. Use a class C fire extinguisher, which is recommended for electrical fires.
• Never repair a break in an outdoor extension cord.. Throw the cord away and buy a new one.
• Don't use indoor lights for outdoor purposes. Use only bulbs, extension cords, wiring, outlets, and other fixtures specifically designed for outdoor use. (Check the manufacturer' s instructions and the Underwriters Laboratories approval).
• Don't touch appliances, cords or plugs with wet hands or while standing on a wet surface. Don't put electrical tools, appliances or cords in water.
• Keep electric rotisseries, radios, wiring for outdoor lighting and other electrical devices away from swimming pools. Never touch an electrical device while in a swimming pool or when standing in water.
• If you encounter an electrical-injured victim, do not touch the person until they have been freed from the source of electricity. You can use a non-conductor, such dry rope or wood to push or pull the victim away from the power source.
• Never raise any tall object near a power line. Carry it level with the ground and be cautious when removing water pipes and well casings.
• Never attempt to open or tamper with transformers. Don't plant shrubs and trees close to them - bushes and trees should be at least ten feet away from the front of the transformer.
• If an appliance works improperly or gives the slightest warning of a problem, such as shocks or sparks, disconnect it and have it serviced.
• Take extra precautions when using power tools.. Your electrical wiring should be adequate for the job. Circuits should be grounded. The tools should be three-pronged or double insulated.
• Protect cords from heat, chemicals and oil. Coil cords loosely when storing tools. If cords are broken, get new ones or shorten them. Never splice broken cords.
• During severe weather, temporary low-voltage conditions can dim lights and remain low longer than a minute. In such cases, turn off or unplug all motorized appliances. Also, turn off televisions and fluorescent lamps.