Understanding the Importance of Electrical Safety

Electrical safety is a critical aspect of our daily lives, yet it is often overlooked until an incident arises. The "Electrical Safety Handbook," authored by experts in the field, highlights essential practices to ensure safety when working with electrical systems. Understanding these principles is vital for both professionals and homeowners alike, as it can prevent accidents and save lives.

The handbook emphasizes the importance of adhering to established safety protocols. Electrical hazards can result in severe injuries or even fatalities if safety measures are neglected. Basic practices, such as turning off power before working on electrical circuits and using insulated tools, are crucial for risk management. Additionally, ensuring that electrical systems are properly grounded helps to prevent shock and fire hazards.

Another significant component covered in the handbook is the importance of regular maintenance and inspections. Electrical systems can degrade over time, leading to potential failures and dangerous situations. Regular checks help identify worn-out components, faulty wiring, or other issues that could pose risks. For homeowners, understanding when to call in a professional electrician can be the difference between safety and disaster.

The handbook also discusses the legal implications of electrical safety. Compliance with local electrical codes and regulations is not just a best practice; it's a legal requirement. Failure to adhere to these codes can result in penalties and, more importantly, can jeopardize the safety of individuals in the vicinity. Knowledge of these regulations ensures that installations and repairs are performed correctly and safely.

Finally, the authors stress the importance of education and training in electrical safety. Whether you're a professional electrician or a DIY enthusiast, understanding the principles of electrical systems is essential. Training programs and resources like the "Electrical Safety Handbook" provide valuable insights into safe practices and the latest technologies, equipping individuals with the knowledge needed to work safely with electricity.

By recognizing the importance of electrical safety and utilizing available resources, we can create a safer environment for ourselves and those around us.

LIFTING AND MANUAL HANDLING HAZARDS AND INJURIES BASIC INFORMATION AND TUTORIALS

HAZARDS AND INJURIES OF MANUAL HANDLING AND LIFTING
What are the Hazards and Possible Injuries of Manual Handling?

The term ‘manual handling’ is defined as the movement of a load by human effort alone. This effort may be applied directly or indirectly using a rope or a lever.

Manual handling may involve the transportation of the load or the direct support of the load including pushing, pulling, carrying, moving using bodily force and, of course, straightforward lifting. Back injuries due to the lifting of heavy loads is very common and several million working days are lost each year as a result of such injuries.

Typical hazards of manual handling include:
S lifting a load which is too heavy or too cumbersome resulting in back injury
S poor posture during lifting or poor lifting technique resulting in back injury
S dropping a load, resulting in foot injury
S lifting sharp-edged or hot loads resulting in hand injuries.

Injuries caused by manual handling
Manual handling operations can cause a wide range of acute and chronic injuries to workers. Acute injuries normally lead to sickness leave from work and a period of rest during which time the damage heals.

Chronic injuries build up over a long period of time and are usually irreversible producing illnesses such as arthritic and spinal disorders. There is considerable evidence to suggest that modern life styles, such as a lack of exercise and regular physical effort, have contributed to the long-term serious effects of these injuries.

The most common injuries associated with poor manual handling techniques are all musculoskeletal in nature and are:

S muscular sprains and strains – caused when a muscular tissue (or ligament or tendon) is stretched
beyond its normal capability leading to a weakening, bruising and painful inflammation of the area
affected. Such injuries normally occur in the back or in the arms and wrists

S back injuries – include injuries to the discs situated between the spinal vertebrae (i.e. bones) and can lead to a very painful prolapsed disc lesion (commonly known as a slipped disc). This type of injury can lead to other conditions known as lumbago and sciatica (where pain travels down the leg)

S trapped nerve – usually occurring in the back as a result of another injury but aggravated by manual
handling

S hernia – this is a rupture of the body cavity wall in the lower abdomen causing a protrusion of part of the intestine. This condition eventually requires surgery to repair the damage

S cuts, bruising and abrasions – caused by handling loads with unprotected sharp corners or edges

S fractures – normally of the feet due to the dropping of a load. Fractures of the hand also occur but are less common

S Work-related upper limb disorders (WRULDs)

S rheumatism – this is a chronic disorder involving severe pain in the joints. It has many causes, one of which is believed to be the muscular strains induced by poor manual handling lifting technique.

WORKS THAT REQUIRE WORK PERMITS BASIC INFORMATION AND TUTORIALS

WORKS THAT REQUIRES WORK PERMIT
What are the Works that Requires Work Permit?

The main types of permit and the work to be covered by each are identified below.

General permit
The general permit should be used for work such as:
S alterations to or overhaul of plant or machinery where mechanical, toxic or electrical hazards may
arise
S work on or near overhead crane tracks
S work on pipelines with hazardous contents
S work with asbestos-based materials
S work involving ionising radiation
S work at height where there are exceptionally high risks
S excavations to avoid underground services.

Confined space permit
Confined spaces include chambers, tanks (sealed and open-top), vessels, furnaces, ducts, sewers, manholes, pits, flues, excavations, boilers, reactors and ovens.

Many fatal accidents have occurred where inadequate precautions were taken before and during work
involving entry into confined spaces. The two main hazards are the potential presence of toxic or other dangerous substances and the absence of adequate oxygen. In addition, there may be mechanical hazards (entanglement on agitators) and raised temperatures.

The work to be carried out may itself be especially hazardous when done in a confined space, for example, cleaning using solvents, cutting/welding work. Should the person working in a confined space get into difficulties for whatever reason, getting help in and getting the individual out may prove difficult and dangerous.

Stringent preparation, isolation, air testing and other precautions are therefore essential and experience shows that the use of a confined space entry permit is essential to confirm that all the appropriate precautions have been taken.

Work on high voltage apparatus (including testing)
Work on high voltage apparatus (over about 600 volts) is potentially high risk. Hazards include:

S possibly fatal electric shock/burns to the people doing the work
S electrical fires/explosions
S consequential danger from disruption of power supply to safety-critical plant and equipment.

In view of the risk, this work must only be done by suitably trained and competent people acting under the terms of a high voltage permit.

Hot work
Hot work is potentially hazardous as a:
S source of ignition in any plant in which highly flammable materials are handled
S cause of fires in all locations, regardless of whether highly flammable materials are present.

Hot work includes cutting, welding, brazing, soldering and any process involving the application of a naked flame. Drilling and grinding should also be included where a flammable atmosphere is potentially present.

In high risk areas hot work may also involve any equipment or procedure that produces a spark of sufficient energy to ignite highly flammable substances.

Hot work should therefore be done under the terms of a hot work permit, the only exception being where hot work is done in a designated area suitable for the purpose.

BIOLOGICAL EFFECTS OF IONIZING RADIATION BASIC INFORMATION AND TUTORIALS

IONIZING RADIATION IMPACT TO BODY
What Are The Biological Effects of Ionizing Radiation?

Information on the biological effects of ionizing radiation comes from animal experiments and from studies of groups of people exposed to relatively high levels of radiation. The best-known groups are the workers in the luminising industry early this century who used to point their brushes with the lips and so ingest radioactivity; the survivors of the atomic bombs dropped on Japan, and patients who have undergone radiotherapy.

Evidence of biological effects is also available from studies of certain miners who inhaled elevated levels of the natural radioactive gas radon and its radioactive decay products. The basic unit of tissue is the cell. Each cell has a nucleus, which may be regarded as its control centre.

Deoxyribonucleic acid (DNA) is the essential component of the cell’s genetic information and makes up the chromosomes which are contained in the nucleus. Although the ways in which radiation damages cells are not fully understood, many involve changes to DNA.

There are two main modes of action. A DNA molecule may become ionised, resulting directly in chemical change, or it may be chemically altered by reaction with agents produced as a result of the ionisation of other cell constituents. The chemical change may ultimately mean that the cell is prevented from further division and can therefore be regarded as dead.

Very high doses of radiation can kill large numbers of cells. If the whole body is exposed, death may occur within a matter of weeks: an instantaneous absorbed dose of 5 gray or more would probably be lethal (the unit gray is defined below).

If a small area of the body is briefly exposed to a very high dose, death may not occur, but there may be other early effects: an instantaneous absorbed dose of 5 gray or more to the skin would probably cause erythema (reddening) in a week or so, and a similar dose to the testes or ovaries might cause sterility.

If the same doses are received in a protracted fashion, there may be no early signs of injury. The effect of very high doses of radiation delivered acutely is used in radiotherapy to destroy malignant tissue. Effects of radiation that only occur above certain levels (i.e. thresholds) are known as deterministic. Above these thresholds, the severity of harm increases with dose.

Low doses or high doses received in a protracted fashion may lead to damage at a later stage. With reproductive cells, the harm is expressed in the irradiated person’s offspring (genetic defects), and may vary from unobservable through mildly detrimental to severely disabling.

So far, however, no genetic defects directly attributable to radiation exposure have been unequivocally observed in human beings. Cancer induction may result from the exposure of a number of different types of a cell. There is always a delay of some years, or even decades, between irradiation and the appearance of a cancer.

It is assumed that within the range of exposure conditions usually encountered in radiation work, the risks of cancer and hereditary damage increase in direct proportion to the radiation dose. It is also assumed that there is no exposure level that is entirely without risk.

Thus, for example, the mortality risk factor for all cancers from uniform radiation of the whole body is now estimated to be 1 in 25 per sievert (see below for definition) for a working population, aged 20 to 64 years, averaged over both sexes5. In scientific notation, this is given as 4 10 2 per sievert.

Effects of radiation, primarily cancer induction, for which there is probably no threshold and the risk is proportional to dose are known as stochastic, meaning ‘of a random or statistical nature’.

WORKING ON TRANSFORMERS AND CIRCUIT BREAKERS SAFETY PRECAUTION TIPS AND TUTORIALS

SAFETY PRECAUTIONS ON WORKING ON TRANSFORMERS AND CIRCUIT BREAKERS
What Are The Safety Precautions on Working on Power Transformers and Circuit Breakers

Take the following safety precautions when working on transformers and circuit breakers:

• Prevent moisture from entering when removing covers from oil-filled transformers.

• Do not allow tools, bolts, nuts, or similar objects to drop into the transformers. Tie tools or parts with suitable twine.

• Have workers empty their pockets of lose articles such as knives, keys, and watches.

• Remove all oil from transformer covers, the floor, and the scaffold to eliminate slipping hazards.

• Exhaust gaseous vapor with an air blower before allowing work in large transformer cases because they usually contain some gaseous fumes and are not well ventilated.

• Stay away from the base of the pole or structure while transformers are being raised or lowered.

• Ensure that anyone working on a pole or structure takes a position above or well clear of transformers while the transformers are being raised or supported with blocks.

• Ground the secondary side of a transformer before energizing it except when the transformer is part of an ungrounded delta bank.

• Make an individual secondary-voltage test on all transformers before connecting them to secondary mains. On banks of three transformers connected Y-delta, bring in the primary neutral and leave it connected until the secondary connections have been completed to get a true indication on the lamp tests.

• Disconnect secondary-phase leads before opening primary cutouts when taking a paralleled transformer out of service. Do not disconnect secondary neutral or ground connections until you have opened the primary cutouts.

• Do not stand on top of energized transformers unless absolutely necessary and then only with the permission of the foreman and after all possible precautions have been taken. These precautions include placing a rubber blanket protected with a rubbish bag over the transformer cover. Do not wear climbers.

• Treat the grounded case of a connected transformer the same as any grounded conductor. Treat the ungrounded case of a connected transformer the same as any energized conductor because the case may become energized if transformer windings break down.

• Ensure that the breaker cannot be opened or closed automatically before working on an oil circuit breaker and that it is in the open position or the operating mechanism is blocked.

• Ensure that metal-clad switching equipment is deenergized before working on it.

• Ensure that regulators are off the automatic position and set in the neutral position before doing any switching on a regulated feeder.

• Do not break the charging current of a regulator or large substation transformer by opening disconnect switches because a dangerous arc may result. Use oil or air brake switches unless special instructions to do otherwise have been issued by the proper authority.

• Do not operate outdoor disconnecting switches without using the disconnect pole provided for this
purpose.

• Ensure that all contacts are actually open and that safe clearance is obtained on all three phases each time an air brake switch is opened. Do not depend on the position of the operating handle as evidence that the switch is open.

• Do not operate switches or disconnect switches without proper authority and then only if thoroughly
familiar with the equipment.

• Remove potential transformer fuses with wooden tongs. Wear rubber gloves and leather over gloves.

• Do not open or remove disconnect switches when carrying load. First open the oil circuit breaker in series with the switches. Open disconnect switches slowly and reclose immediately if an arc is drawn.