Fire Hazards And Precautions

A first line support technician must be aware of the potential risks in an environment that uses computers and their peripherals. The technician should also be aware of safe working practices. This includes not only taking care of the human element within a workplace but also the proper care and handling of equipment.

Health and safety issues range from the straightforward, e.g. common sense placement of a single computer, to the complex, e.g. hundreds of computers and other devices that have to be networked together.

Generally, computers are regarded as being safe devices that do not suddenly blow up or burst into flames. However, because all devices that use electricity have a potential to become dangerous coupled with the rapid strides in technology that has made computers faster and more powerful there are components within a computer system that can get very hot.

In most instances, the safety devices built within the computer system should prove adequate, e.g. fuses and circuit breakers but there may be cases when, due to unforeseen circumstances, a fire happens. In the case of a fire there are steps that can be taken that will minimise human injury and computer damage.

Fire Awareness Tips

Due to the serious nature of fire and its consequence it is vital that you are aware of what is best to do if you discover a fire. Every workplace is legally bound to provide its staff with details of fire exits, meeting points, and other guidelines about what to do in the event of a fire. It is the employees responsibility to familiarise themselves with this information.

The following are a general list of advice that you should follow if you discover a fire:

You should try to put a fire out only if you discover it in its early stages and you are completely confident that you can put it out. Be aware, however, that even a small fire can spread quickly and soon become out of control. You safety and your fellow workers safety comes first.

If you do decide to tackle the fire, make sure that if you can’t control it that you can still escape and that your exit is not blocked. Also be aware that fire extinguishers are only designed to fight fires in their very early stages and that the extinguisher may not be adequate if the fire spreads and the room becomes filled with smoke or fumes.

If you believe that the fire cannot be easily dealt with you should immediately set off the nearest fire alarm by breaking the glass and then leave through the appropriate fire exit. The fire brigade should be contacted immediately.

Fire Prevention Tips

There are many common sense approaches with regards to cutting down the risk of fire with relation to computer equipment, including:

Regular cleaning and maintenance of equipment, e.g. to cut down the build up of dust in a system.

Taking care not to expose computer equipment to water or other possibly damaging liquids, e.g. refraining from placing potted plants that have to be watered on top of computing equipment.

Making sure that ventilation ducts are clear and free from obstruction.

Making sure that cables are not frayed or damaged in any way.

Fire Extinguishers

It is vital that first line support technicians have an awareness of the different types of fire extinguishers that are available, the purpose of each and how to use them.

The first thing to note regarding fire extinguishers is that they are only designed to fight fire in its early stages. There are many types of fire extinguisher that are designed to suit different situations in which a fire may occur and it is important that the correct extinguisher is used for the type of fire being fought.

Classes of Fire

Depending on the country you are in there are slightly different categorisations of fire, .e.g. USA and Europe. We will examine the European classifications.

In Europe, fires can be divided into six classes:

Class A: These are fires involving flammable solids, e.g. wood, cloth, rubber, paper, and some types of plastics. An example of this type of fire would be a campsite fire.

Class B: These are fires involving flammable liquids or liquefiable solids, e.g. petrol, oil, paint and also some waxes & plastics, but not cooking fats or oils.

Class C: These are fires involving flammable gases, e.g. natural gas, hydrogen, propane, butane.

Class D: These are fires involving combustible metals, e.g. sodium, magnesium, and potassium.

Class E: These are fires involving any of the materials found in Class A and B fires, but including electrical appliances, wiring, or other electrically energized objects in the vicinity of the fire, with a resultant electrical shock risk if a conductive agent is used to control the fire.

Class F: These are fires involving cooking fats and oils. The high temperature of these types of fats and oil when on fire far exceeds that of other flammable liquids which means that normal fire extinguishers should not be used.

Extinguisher Maintenance

Al fire extinguishers should be regularly checked to make sure that they are fully functional and ready to use if required.

In the UK, there are three types of maintenance required:

Basic Service – All extinguishers require this service annually and it includes checking pressure, weight and any other indication of damage.

Extended Service – Water, wet chemical, foam and powder extinguishers have to be serviced every five years and the examination is more detailed than the basic service and includes a test discharge.

Overhaul – CO2 extinguishers require a thorough service every ten years.

Each of the services includes the examiner signing and date stamping that the service has taken place.

There are other items that can be used to fight fire such as fire blankets and hose reels but these are outside the remit of the course.

Types of Extinguisher

We will look at the following types of fire extinguisher:

Water and Foam

Carbon Dioxide

Dry and Wet Chemical

Powder

Water and Foam

Water extinguishers work by quickly removing the heat from the fire. Water extinguishers are only suitable for fighting Class A fires that involve materials such as wood, paper and textiles. Water should not be used to fight Class B fires because flammable liquids could be spread by the steam from the water, neither should they be used for Class E electrical fires because water conducts electricity there is a risk of electrocution.

Foam extinguishers work by quickly removing heat and oxygen from the fire. Foam extinguishers are suitable for Class A and Class B fires. They are especially suited for controlling Class B flammable liquid fires because the foam has a blanketing effect that smothers the flames without spreading the fire.

Carbon Dioxide

Carbon Dioxide (CO2) extinguishers work by removing the oxygen element from the fire. Carbon Dioxide extinguishers are suitable for Class B and Class E fires, i.e. involving flammable liquids and electricity respectively

Carbon dioxide extinguishers should not be used in confined spaces because they reduce the oxygen in the air. Also, do not hold the nozzle while using because this may lead to injuries such as cold burns because the CO2 is released at extremely low temperatures.

Wet and Dry Chemical

Wet chemical extinguishers work by removing the heat from the fire and by creating a barrier between the fuel and oxygen. Wet chemical extinguishers are suitable for Class F fires, i.e. cooking oil and fats, which can reach extremely high temperatures.

Dry chemical extinguishers work by removing the chemical reaction of the fire. Dry chemical extinguishers are suitable for Class A, Class B and Class C fires, i.e. involving flammable liquids and electricity respectively

Powder

Powder extinguishers work by removing the heat from the fire or by separating the fuel and oxygen. Powder extinguishers are suitable for Class A, Class B and Class E fires.

Fire Extinguishers Task

Go to this website and have a look through this resource on Fire Extinguishers. Have a go at the quiz at the end of it to see how much you have learned.

Good Luck.

Click on this link for a useful flash tutorial on fire extinguishers.

Electrical Hazards

Anything that uses electricity to work contains a risk that if it is faulty then it could lead to an electric shock. There are certain devices that are considered more dangerous than others and users should be warned that trying to fix these would be best left to professional electronic engineers, e.g. a computer monitor should not be opened even after mains power has been switched off because a dangerous electrical charge remains.

Computers and their associated peripheral, such as printers, scanners are powered from the mains and as such are a potential hazard. Therefore, the risk of electric shocks applies to all users and not just technicians who have the systems opened while they are working with them.

Greater care must be exercised when a technician is working with an open system. It is advised that all of the equipment under repair or modification is disconnected from the mains supply during the entire process.

Hazard Protection

There are different hardware devices that can be used to guard against human injury and damage to expensive equipment. These include:

Fuses

Circuit Breakers

Residual Current Devices

These devices are designed to carry out one or more of the following:

Reduce the risk of fire

Reduce the risk of electrical shock

Reduce the risk of equipment damage

Fuses

Fuses and circuit breakers are devices that protect an electrical system from overload and short circuits. These devices are designed to protect equipment rather than users.

These devices are current sensitive which are designed to cut power if the current rises above a preset limit.

Fuses are a very common way of protecting equipment from power overloads and can be found in many places including the home. Any device, e.g. TV and Video, which connects to the mains, will have a fuse in the plug. If you open a fuse you would see a thin wire or foil which will vaporise quickly if an overload of current goes through it. The fuse must then be replaced in order for the device to work again.

Circuit Breakers

A circuit breaker is an electromechanical device that carries out a very similar job as a fuse. They are designed to make circuits under normal conditions and to break circuits in the event of an overload, .e.g. a short circuit.

The key difference between a fuse and a circuit breaker is that once a fuse has performed it duty it needs to be replaced, whereas a circuit breaker can be reset.

Modern electricity supplies use circuit breakers rather than fuses and these will be located at different locations in a building.

In the event of a circuit breaker ‘tripping’ and cutting power, then this will allow an engineer to check the equipment for any faults before the circuit breaker can be safely reset.

Another advantage of circuit breakers is that they can be switched off manually to allow safe repair and maintenance.

Residual Current Devices (RCD)

This is a device for human safety rather than solely protecting computer equipment and its function is to minimise the possibly of injury through electric shock. An RCD works by detecting if electricity is ‘leaking’ from a circuit and if so it breaks the circuit.

Most RDCs are combined with a circuit breaker and so will protect equipment in the case of an overload.

Typically, RCDs can be tested by pressing a testing button with should cause the device to operate as if a dangerous leakage had occurred. If the device operates properly, it can be used in a live environment and will perform its function. RCDs should be checked on a regular basis to make sure that they are still functioning properly.

PAT Regulations

Portable Appliance Testing (PAT) is part of the Electricity at Work Regulations 1989 legislation. This legislation places legal implications on employers to ensure the safety of electrical devices in the workplace and the person most likely to carry out this kind of testing the first line support technician.

The ‘portable’ refers to any electrical item that can be moved from one location to another and therefore includes PCs, printers, scanners and many other electrical objects that can be found in the workplace.

There are three parts to PAT:

– Visual inspection

– Earth continuity test

– Insulation test

PAT testing should be carried out a regular intervals, however, a common time frame is every 12 months.

Electro Static Discharge (ESD)

Electro Static Discharge (ESD) can cause a lot of damage to electronic components, such as those found in computer systems, e.g. the processor and RAM.

The amount of ESD required to destroy or damage a computer component would not register with a human and at most a person would feel a little shock.

Many of the semiconductor chips (integrated circuits) and other components in a computer system operate at a low voltage and can be irreparably damaged by ESD2-5 volts and can be damaged by as little as 40 volts ESD.

The causes of ESD include:

People moving about normally

Equipment being moved

Low humidity

Poor connections

Unshielded cables

Improper grounding

Minimising ESD

Steps should be taken to minimise ESD, particularly by technicians working with components that are most susceptible to damage by it. Example solutions could include:

Installation of humidifiers to cut down on low humidity conditions

Changing the work environment, e.g. removing carpets

Training of staff to make them aware of the problem

The use of devices or equipment to minimise ESD

Anti-Static Precautions and Safety Hazards

Probably the most common guard against ESD when working with computer components is an anti static wrist strap. This is a conductive strap that has a wire attached. The wire is typically attached to the computer’s casing or could be connected to a special plug inserted into an ordinary mains socket or to an anti static work mat.

An alternative to a wrist strap is an anti static heel strap which performs the same function but will be connected to a anti static floor mat.

Warning: an important safety issue when using an antistatic device is not to work on any equipment where there is a possibility of touching a live or high voltage component. The anti static device will form an excellent path for the electricity to flow to ground through your body, and that would be extremely dangerous.

It is also important that when touching components, such as processors and

LSZH Sheathing Cable Protection

Low Smoke Zero Halogen is a special type of cable sheath used by manufactures for a variety of types of cable, including network cables. Unlike the normal PVC cable covering used that can produce toxic and corrosive gases when it burns, this type of cable covering does not release dangerous gases when it burns.

Many organisations’ structured cabling schemes require that several cables be run together. This can be extremely dangerous in the event of a fire because of the greater amount of PVC burning result in an increase in life threatening fumes. Generally, when this is the case, organisations will choose to install LSZH cabling.