Ch. 4.4
Portable systems are fire extinguishers that can be used to suppress small fires. Be aware of the following facts when using a portable fire extinguisher:
*A pin is inserted in the handle of most fire extinguishers to prevent the extinguisher from being accidentally triggered. Remove the pin to use the fire extinguisher. *Use the PASS method (Pull, Aim, Squeeze, and Sweep) to administer the fire suppressant. Aim toward the base of the fire. *Fire extinguishers usually have a limited effective range of 3-8 feet, *Be aware that fires spread quickly. In most cases, you will be unable to control a fire with just a portable system.
The type of fire extinguisher you select should be based on the type of fire that is likely to occur in the area. The following table lists various U.S. fire classes and the appropriate suppressant type:
*Class A- Fuel type: Wood, paper, cloth, plastics, Suppressant type: Water or soda acid *Class B- Fuel type: Petroleum, oil, solvent, alcohol, Suppressant type: CO2 or FM200 *Class C- Fuel type: Electrical equipment, circuits, wires, Suppressant type: Halon or CO2 *Class D- Fuel type: Sodium potassium, Suppressant type: Dry powders *Class K- Oil, solvents, electrical wires, Suppressant type: Halon, CO2, soda acid
Computer systems are sensitive to environmental conditions. Environmental controls that can be implemented to protect computer systems include:
*Cool temperatures to protect hardware from being damaged by overheating. *A humidity controlled environment to keep humidity above 50% to avoid electric shock. *Moisture detectors to alert responsible individuals early and prevent water/flood damage from water pipes and sprinklers. *Fire suppression controls to prevent damage from heat and smoke.
A fixed system is part of a building and typically combines fire detectors with fire-suppression technology:
*Fire detectors detect rapid changes in temperature or smoke. *Fixed fire suppression systems usually use water or gas to extinguish fire. *Deluge sprinkles have open sprinklers, and the pipes are dry until the fire alarm causes the deluge valve to open and send water to all the sprinklers. *Wet pipe sprinklers contain pressurized water that is released when initiated by a heat-sensitive device. Wet pipe systems respond to fire threats more quickly than deluge systems. Be aware that a fixed system might only slow down a fire, giving you extra time to evacuate; it might be incapable of actually extinguishing a fire.
Fire requires 4 components:
*Fuel such as wood, paper, or petroleum. *Heat, which triggers the fire and raises the temperature of surrounding materials, bringing them closer to a combustible point. *Oxygen for the oxidation of the combustible material. *The chemical reaction that occurs as the oxygen and the fuel ignite.
A well-maintained heating, ventilating, and air conditioning (HVAC) system is important for employee comfort and the protection of equipment.
*HVAC controls the temperature and humidity of a building. *HVAC keeps temperatures cool for computer systems. *Computer systems and server rooms should be centrally located and have separate ducting for better controls. *Computer rooms/server rooms require full-time environmental controls.
Recommendations for water and gas focus mainly on the ability to turn them off in the event of a broken pipe, fire, or other type of emergency. These recommendations are:
*Identify the location of a master shut off valve *Identify the location of any secondary shut-off valves (using secondary shut-off valves minimizes the impact of the service loss) *Ensure that the shut-off valves work *Mark shut-off valves to increase vulnerability *Ensure that appropriate personnel have access to shut off valves for water and gas systems *Secure shut-off valves from general access
Radio frequency interference (RFI)is the reception of high-frequency radio waves. Sources can include:
*Microwave ovens *Wireless devices *Transmitting devices *Cellular phones *Florescent lighting
Electro-magnetic interference (EMI) is caused by noise between the hot wire and the ground or neutral wires in a circuit. It can disrupt the signal in a data table. Common causes of EMI are:
*Motors *Heavy machinery *Lights *Electrical systems (foe example, computer system)
EMI shielding is the process of protecting computer systems from interference to prevent transmission problems and security concerns, such as eavesdropping. Methods to shield computer systems include:
*Surrounding a server room with a faraday cage to protect a system from RFI. *Creating a TEMPEST environment or control zone to reduce electronic noise from devices. A key consideration inside the building is the location of the data center. Recommendations for location choice include: *Locate the data center as close as possible to the center of the building. *Do not locate under water pipes or in any other area that might be subject to flooding or water damage. *Make sure walls have a minimum fire rating of one hour and go all the way to the true ceiling. *Reduce the number of inbound doors. *Have small windows that a human cannot fit through. *The data server room should be the most restricted are of the facility. Thus, it should be located in an area where security can be easily and thoroughly implemented.
Recommendations for HVAC systems include:
*Use positive pressure systems, they protect the air quality in the facility by causing air to be forced out through doors, windows, and other openings. Negative pressure systems draw air in, potentially bringing in airborne particles such as dust, smoke from a fire, or contamination from a chemical leak. Positive pressure systems are more energy effective. *Protect filter air intakes. The air intakes are the source of air for the positive pressure system. Air intakes can be a target of sabotage or contaminated by toxic chemicals if an incident occurs in the surrounding area. *For electronic components, keep temperature between 70 and 74 degrees and humidity between 40% and 65%. *Ensure that appropriate personnel have access to shut off values for HVAC system in the event of an emergency.
Extinguishing agents used to suppress fires include:
*Water to remove the heat. Water can cause damage to computer equipment, but it is harmless to people. *Gas to displace oxygen. When extinguishing a fire around critical equipment, the best option is to eliminate oxygen because that would have the least damaging effect. The task almost always involves a gas (such as CO2 and Halon) that does not leave a damaging residue. Be aware of the following when using gas systems: *They don't work well in an open environment, and special ventilation may be required. *Evacuate the room immediately; removal of oxygen can suffocate someone in the room. *Dry chemicals (such as sodium bicarbonate), wet chemicals, and foam can be used to extinguish fuel from burning, but will leave a residue and cause damage to the computer equipment.
Be aware of the following facts regarding responding to fire emergencies:
*When a fire occurs, the first action is to ensure the safety of the people and evacuate the area. *In most cases, you should not attempt to put out a fire yourself. Fires spread quickly and become out of control, placing you in danger. *Never go back into a burning building to retrieve data or computer systems. Performing regular backups and and storing media offsite before the emergency is the best way to protect valuable data. *Education is key to proper response in the event of an emergency. Be sure to train employees that fire moves quickly and there is little time to waste to ensure safety and protect assets. *CO2 suppresses fire by eliminating oxygen. In addition to smothering fires, CO2 is toxic to humans. If you use CO2 to suppress a fire, you must evacuate the area and exhibit extreme caution. *Inspect fire extinguishers regularly for proper pressure. *Face the fire. Do not turn from it; back away from it instead. *Never reuse a fire extinguisher. It could have inadequate pressure, or the nozzle could become clogged. It is usually less expensive to simply purchase a new fire extinguisher.
What is the recommended humidity level for server rooms?
50%
blackout
A complete electrical power failure.
redundant power source
A device that ensure constant power, such as a backup generator or power from a secondary source.
line conditioner
A device that improves the quality of electric power by providing filters to remove noise, temporary voltage regulation, and surge protection.
uninterruptible power supply (UPS)
A device that protects against under-voltage conditions of short duration.
surge protector
A device that protects against voltage spikes that damage components.
transient
A fluctuation caused by line noise or disturbance.
fault
A momentary power outage that can have a variety of sources.
sag or dip
A reduction in voltage in electrical power that last for a short period of time.
brownout
A reduction in voltage that lasts longer than a few seconds.
surge or spike
A sudden rise in voltage in electrical power.
Which of the following is the least effective power loss protection for computer systems?
A surge protector is useless in the event of power loss.
TEMPEST
A technology involving the monitoring (and shielding) of devices that emit electromagnetic radiation (EMR) in a manner that can be used to reconstruct intelligible data.
Components within your server room are failing at a rapid pace. You discover that the humidity in the server room is at 60% and the temperature is at 80 degrees. What should you do?
Add a separate A/C unit in the server room.
A brownout is generally caused:
At the utility company during times of high power usage. The ANSI standard defines a brownout as an 8% drop between the power source and the voltage meter or a 3.5% drop between the voltage meter and the wall outlet.
Ways a surge or spike can be caused:
Can be caused by a lightening strike, a power plant coming online or going off-line, or even equipment inside the facility.
Which of the following fire extinguisher suppressant types is best used for electrical fires that might result when working with computer components?
Carbon dioxide (CO2)
Which of the following fire extinguisher types is best used for the electrical fires that might result when working with computer components?
Class C
Which of the following statements about ESD is NOT correct?
ESD is much more likely to occur when the relative humidity is above 50%.
Environmental monitoring
Environmental conditions have a substantial impact on the reliability and life span of IT equipment. Environmental monitoring should be implemented in server rooms and data centers to ensure the proper function of environmental controls. The goal of environmental monitoring is to maintain environmental conditions and keep them as stable as possible. Keep in mind the following regarding temperature: *Heat reduces the life span and reliability of computer equipment. *Fans and cooling systems on users' desktop, laptop, and notebook computers are usually adequate to keep those types of equipment sufficiently cool. *Server rooms require special cooling systems due to the high concentration of equipment. *The optimum temperature for computer equipment is 68 degrees Fahrenheit (20 Celsius). *There is a variety of environment sensors and software available to monitor the temperature in server rooms and data centers. *Environmental sensors and and software can also help you identify hot spots. *Temperature sensors are generally located one and a half to two feet above the floor and five to six feet above the floor throughout the room. A variation of more than 12 degrees between low-mounted and high-mounted sensors indicate a problem. Air flow is an important factor in controlling temperature. Be aware that: *Fans are a critical component in preventing hot spots in a computer room. There are two types of fans: *Fans inside the computer equipment. *Room fans, which circulate the air in the room. *The air exchange rate for a computer room is much higher than for an office area. *An office area needs approximately two air changes per hour. *A server room needs between 20 and 30 air changes per hour. Humidity is also an important consideration for server rooms: *Humidity should be kept within a range of 45 to 65 percent. *Too much humidity results in condensation. *Too little humidity results in electrostatic discharge (ESD). *Depending on the naturally occurring humidity level of your area and the season, you may have to add humidity or use a de- humidifier. *Avoid large, rapid changes in humidity. Keeping a narrow range of temperature in the computer room will help to avoid condensation. *Many temperature sensors also monitor humidity. Although sensors can keep you updated on specific temperature and humidity in the server room, you may want to consider implementing video monitoring. Being able to see what is happening in the server room can alert you to problems before the sensors register the change.
Which of the following fire extinguisher types poses a safety risk to users in the area? (Select two)
Halon and CO2
Radio Frequency Interference
High-frequency radio waves that disrupts the radio signals in wireless communication systems.
You walk by the server room and notice a fire has started. What should you do first?
Make sure everyone has cleared the area.
electro-magnetic interference
Noise between the hot wire and the ground or neutral wires in a electrical power circuit that disrupts the signals in data cables.
You maintain the network for an industrial manufacturing company. You are concerned about the dust in the area getting into the server components and affecting the ability of the network. Which of the following should you implement?
Positive pressure system
AC power
Power systems can help keep electrical service constant. The following types of protection are available to improve and protect your equipment for AC power issues: *Surge protectors protect against spikes that damage components. Many power strips have a built-in surge protector. *Uninterruptible Power Supplies (UPS) protect against under-voltage conditions of short duration (depending on battery life, 30 minutes or more). Most UPS systems include a line conditioner and a surge protector. *A redundant power source to ensure constant power. An example of a redundant power source is a backup generator or power from a secondary source in case one source fails. Backup generators require fuel to operate and can provide power to critical systems until the fuel is consumed. *Line conditioners (also known as power conditioners) are used to improve the quality of the power by providing one or more of the following: *Filters to remove noise *Temporary voltage regulators *Surge protectors The order in which critical equipment should draw power is: *UPS line conditioner *UPS battery *Backup generator
Besides protecting a computer from under voltage, a typical UPS also performs which two actions.
Protects from other voltages and conditions the power signal
Infrastructure
Refers to the systems that support the site. Infrastructure includes AC power, heating, ventilation and air conditioning systems (HVAC), gas and water. Of these systems, AC power can present the greatest challenge on a day-to-day basis.
heating, ventilation, and air conditioning (HVAC)
The system used to provide heating and cooling services to buildings.
Hot and cold aisles
To ensure proper cooling, make sure server rooms have separate ducting or cooling systems from the rest of the building. The use of hot and cold aisles within the server rooms is an effective method for reducing the temperature of server rooms. A cold aisle is created by having the front of the equipment face toward the center of the aisle. Hot aisles have the back of the equipment face the aisle. Air from the cooling system is forced into the cool aisles from underneath and exhausted through the hot aisles overhead. Typically, cold aisles face air conditioner output ducts and hot aisles face air conditioner return ducts. Best practices for hot aisle/cold aisle containment include: *Install internal fans to bring air into or exhaust it out of individual units to act with, not against, the overall pattern of air flow in the center. *Locate devices with side or top exhausts in their own part of the data center. *Raise the floor 1.5 feet so that air being pushed by air conditioning equipment can pass through. *Install automatic doors in the data center.
Sources of sags or dips:
chained power strips, faulty wiring, sudden power draws, (such as when equipment is first turned on), and large inductive sources, such as an electrical motor.
A blackout can have a variety of sources such as:
downed power lines or failed transformers
Products produced by fire combustion include:
water, carbon dioxide (CO2), smoke, and heat.