Critical Systems Final Flashcards
Where does the transfer of information begin?
The user or customer by receiving or sending information from computer via internet
Where does the data info enter the Data Center first?
Main Telecom Closet or Corporate Cable Room, processed into the main switches or routers
What are the three main ways data info can be transmitted from a Data Center?
Phone utilities (hard wire), micro-emitter, radio frequency
How can a data center be considered down if there is no interruption in critical power or critical cooling?
Without a method of sending or receiving data from and to servers - issue with telecom, radio frequency, or micro-emitter
An intranet connection is considered what type of network?
Internal or secured network for a group (business, organization, etc.), private network within a building or organization
Define internet.
Vast computer network linking computer networks worldwide using the same set of communication protocols
What devices store all data info on a data floor?
Blade Servers
What devices find, route, and send info or data from the blade servers to the user?
Communication swtiches like Cisco or Nexus. MDF, IDF, TOR (top of rack)
What do the following abbreviations stand for? CPU, MDF, IDF
Central Processing Unit, Main Distribution Function (a switch), Intermediate Distribution Function (capacity adding switch)
What is the purpose of an Extranet?
Intranet extended to customers, partners, suppliers or anyone not employed by the company. Ex. Online Banking
What is reactive maintenance?
Waiting for component/system failure before repairing a systems. Leads to downtime
Under the Documentation and Human Factor section of the chapter, how is information on Data Center Maintenance used?
Ever-increasing volumes of data force documents to be maintained for reference on components and systems, used to develop Methods of Procedure, Escalation Procedures, Maintenance Procedures, Risk Management Assessment, and certifications and education. Creation of living documents
Under the Education and Training section, why must data center management train all personnel?
Increases shared knowledge, limits added risks leading to human error, and limits downtime during critical environment event and maintenance
Under Standards and Benchmarking, what is the key?
Benchmark the facility on routine basis to identify deviations in operations from original design specs
Under the Testing and Commissioning section, why is integrated testing important?
Assures facility systems work together properly according to design, which limits envronment events and works to protect equipment
What are the main objectives of the U.S. Patriot Act, Basel II, and Sarbanes-Oxley Acts?
- Assure public safety, confidence, and services. 2. Establish responsibility and accountability. 3. Encourage/facilitate partnering among all government levels. 4. Encourage market solutions. 5. Facilitate meaningful info sharing. 6. Foster international security cooperation. 7. Develop technologies and expertise to combat terrorist threats. 8. Safeguard privacy and constitutional freedoms. 9. Raise confidence level of investors/shareholders while publically reporting. 10. Create harsh new punishments for scams and other violations
The U.S. Patriot Act defines critical infrastructure as?
Systems and assets, physical or practical, that are so crucial to U.S. that the annihilation of such systems would have many devastating impacts on not only security, but national economic security and national public health and safety
Basel II was adopted for financial institutions. Why does Basel II affect data centers or info technology?
Requires higher security for private info on servers and requires protection systems for data centers to reduce downtime. Because global 24hr banking
Sarbanes-Oxley Act (SOX) requires major changes in security laws. Reviews of policies and procedures with attention to data standards and IT process, what are the key parts of the review process?
How vital corporate data is stored, managed, and protected. Focus is on availability, integrity, and accountability. Ensures corporations have accurate, up-to-date info for audit review, defines reporting requirements, eliminates security exposure, and automated finanacial reporting
NFPA 1600 requires what kind of approach?
“All Hazards” approach, which means assessment of all hazards by a business, along with risk assessments to develop program for mitigation, preparedness, response, and recovery
What is the main reason 100% uptime cannot be achieved?
Human error, natural weather disturbances, terrorist activities
What is the average life span of most server equipment?
3 years. Technology changes every 18 months
Data centers average how much power usage in Giga Watts in the U.S. alone?
418gW
Basel II defines categories of loss events as?
Levels or categories. Level 1: damage to physical assets or system failure. Level 2: Disasters and other events, business/system disruption. Level 3: Natural disaster losses, human losses, hardware and software losses, and utility losses
What does the Sarbanes-Oxley Act require from businesses that use information technology?
To not risk losing data or even risk downtime that could jeopordize accessing info in a timely fashion
What does NFPA stand for?
National Fire Protection Agency
What percent of failures can be attributed to human error?
50%
How much downtime is associated with 99.9% of uptime?
8.76 hours
What are the N+1 and N+2 critical electrical configurations applied to?
Utility services, P distribution, UPS, Emergency and standby generators, fuel systems to emergency standby generators
What are the seven steps to improved reliability and maintainability?
- Planning and Impact Assessment. 2. Engineering and Design. 3. Project Management. 4. Testing and Commissioning. 5. Documentation. 6. Education/Training, and annual Certification. 7. Operations and Maintenance
To avoid downtime facilities managers also must understand?
All trends affecting the utilization of data centers, given the rapid evolution of technology
What is the key to protecting an investment such as a data center?
An effective maintenance and testing program for main electrical loads
In a mission critical power distribution system, what are the two basic architectures for power distribution to critical loads?
- Electrical power from UPS system connected directly thru transformers or redundantly from two sources thru STS to remote mounted circuit breaker panel with branch circuits to critical loads. 2. Power from UPS system fed to PDUs, which house transformers and panel boards with branch circuits running to critical loads
What code provides safety and regulations from electrical shock, short circuits, and arc flash trauma?
NFPA 70E
Infrared scan of an ATS or STS identifies what?
Abnormal heat in electrical components (higher risk of failure)
Acceptance and Maintenance testing are pointless unless?
Test results are objectively evaluated and compared to standards and previous test reports that have established benchmarks
What is the definition of Reliability?
Probability that some item will perform satisfactorily for specified period of time under stated set of conditions
What is the definition of Availability?
Probability that an item will be operational at randomly selected future instant in time
What are the definitions of N+1 and N+2?
N+1 is combo of two basic scemes that meets criteria of furnishing an essential component plus one additional component for backup. N+2 is a premium system designed to provide power to an essential component plus two components for backup. Dual utility electric service
What are the four steps to improve reliability and maintainability of a data center?
Proper design, construction, testing, and maintenance
What does the term PM stand for?
Preventative Maintenance: completion of tasks performed on a defined schedule based on manufacturer’s recommendations to avoid voiding the warranty
What is a BTU and how many BTUs does it take to remove one pound of water from the air?
British Thermal Unit: amount of energy required to raise one pound of water one degree farenheit. 970-1000 BTUs to remove one pound of water from air
How is heat removed from the air by a CRAH?
Dehumidifies the air by cooling below Dew Point when air runs through the evaporator. Uses chilled water
How does the media in a cooling tower help dissipate the heat from the water?
Increases the heat exchange surface area and acts as a baffle to slow down the water flow to increase contact time with the heat exchange media
How is heat transferred from the water in the condenser and evaporator bundles of the chillers?
Room air blown across heat ex coil in evap, heat-laden fluid transferred to heat ex for evap/cond, heat transferred to cond water, which is sent to cooling tower to reject heat outside
What is the main disadvantage of a screw compressor?
Amount of energy required to produce more tonnage of cooling is enormous. Could require 1000V
What is the main advantage of dry-cooler over a cooling tower?
Mechanical cooling provided by the compressor can be eliminated during low ambient temps, providing energy savings to owner (Economizer mode)
What is the fundamental purpose behind a data center cooling system?
Provide adequate cooling, so computer equipment can operate in safe operating temperature range, which prevents downtime and damage
What are the four basic types of fluids used in cooling?
Air, water, refrigerant (Direct Expansion Cooling), Glycol-water mixture
What are the two major cooling distribution methods?
Air-cooled Chiller (packaged unit), Water-cooled Chiller (Evaporative cooling with cooling towers)
What is the definition of a chiller?
Mechanical refrigeration equipment that produces chilled water as a cooling output
What is the difference between water cooled chillers and air cooled chillers?
Air-cooled exchange heat to a refrigerant loop, which has air blown across a condenser coil to reject heat. Water-cooled uses a cooling tower
What type of circuit breakers are used for the main input breaker and alternate breaker?
High E, vacuum and spring operated breaker (high tension spring reduces arc flash)
When the electrical power enters the UPS system, what is the first thing the power does?
It is rectified to DC
How long does the rotor of a Rotary UPS rotate after a loss of power from the switchgear?
Predetermined time period based on need and design
What mode of operation does the UPS enter if there is a failure of any internal components of the UPS?
Bypass from battery operation
What is the average length of service time of the batteries of a UPS system before they are replaced?
3 years
Does an STS have any mechanical moving parts to switch power sources?
No, switching completely by SCR
What device of an STS is required to translate info between the circuit boards of the STS and the Mimic Screen?
Human Machine Interface translates code into something we understand
What is required for an ATS to perform a Closed Transition Switch between power sources?
Sync Relay or Isochronous Governor (for a generator)
According to OHM’s Law, as a component’s resistance increases the power will do what and the temp will do what?
Dissipate more, heat will rise
What does an ATS do?
Transer mechanism and control panel that recognizes loss of normal power, initiates start for generator or emergency power, monitors emergency power, and if quality is good, will switch power connection
At what percentage of nominal voltage does an ATS process begin starting a generator or ATS switching to alternate source?
80%
If the ATS has a manual transfer switch what does it need to operate?
A qualified technicial to operate it
An arc is drawn when contacts switch from one source to another under load. What increases the duration of the arc?
If the voltage is higher and power factor lower or if the amperage is high
Time delays are important to an ATS application. What do time delays allow for?
Start time delay override engine start form momentary deviation in normal power supply, transfer time delay, return to utility, engine warm up, engine cool down
What are the four major functions of an STS?
1.Allows maintenance and repair of upstream components without affecting load. 2. Prevents upstream component failure from affecting load. 3. reduces transformer in-rush current from transformers connected to STS output, which reduces breaker tripping. 4. Provides data to help management meet key elements of SOX, Basel II, NFPA 1600
What is a SCR and what does it do?
Silcon Controlled Rectifier: electronic element that controls power flow between source and load. Determines which source will power the load
During normal operatoin, how are the power sources of an STS identified?
Logic control monitors the power supplies. If an anomaly occurs on the normal supply, it can switch to emergency feed
An STS needs to be monitored to alert operators of defects, faults, and transfers. How do the STS communicate to operators?
The logic provides and interface, typically multiscreen and graphical, and can be BAS integrated
Human error accounts for 40-60% of mission critical site problems. How do STS suppliers address human errors?
- Operating instruction written in text on graphical screen and voiced. 2. Step by step graphical icons. 3. One display for STS/transformer systems, so one place to view all data. 4. STS and STS/transformer systems with door alarms for psychological barriers. 5. Password and PIN or fingerprint/swipe card for psychological barriers
What percentage is utility power available for a year from the power grid and how many hours of downtime is that a year?
99.9%, 8.76 hours
What are the four phases of the cycle of electricity?
Generation, transmission, distribution, end use
Why is AC power preferred over DC?
AC is easier to generate and transformers can adjust voltage for many different power requirements
What is single phase and what is three phase power?
Single: Center-tapped from single transformer with two hots, neutral, and ground. (Typ. 120/240, 115/230, 110/220). Three: Sine waves 120 degrees apart, 3 hots, neutral and ground. (Typ. 120/208, 277/480, 2400/4160)
What is the definition of Transient Voltage?
Change in voltage and/or current, usually initiated by some type of switching event (energizing capacitor bank or electric motors). “Ghosts”
What is the definition of Sag?
Usually occurs when large load is energized, creating a voltage dip below 10% of normal voltage for a half cylce to one minute
What is the definition of Swell?
Usually occurs when large load is turned off, creating a voltage jump above 10% of normal voltage for a half cylce to one minute
When referring to harmonics, what are liner loads and non-linear loads?
Linear: draw current in linear fashion without creating harmonics (motors, heaters, capacitors). Non-linear: draw current intermittently and produce harmonic distortions within a facility (switching power supplies and electronic ballasts)
What are the five steps in Tsing and correcting power problems?
- Interview personnel whom observed the issue and take measurements. Use data to determine issue. 2. Identify solution. 3. Implement solution. 4. Observe and measure all data in problem area to confirm solution. 5. Institute procedure to prevent this in the future
What is the definition of generator?
Device that converts mechanical energy into electrical energy
What is a Prime Generator used for?
Power generation in off-grid circumstances
What are the four recommended maintenance intervals for engin generator maintenance?
Daily, weekly, monthly, annually
Name two reasons why record keeping is important in generator operations and maintenance?
- Required by certain agencies for life safety and environmental purposes. 2. Trend logging generator ops provides maintenance before failure and prevents voiding manufacturer’s warranty
Name three fire protection devices that will also require maintenance or testing in a generator enclosure?
VESDA (Very Early Smoke Detection Alarm), A/V, Vapor Fire Mist System
What four categories of equipment based on reliability requirements and the time that the power supply can operate without electrical power?
- Data processing equipment needing UPS. 2. Safety equipment defined by codes that require power restoration within seconds. 3. Essential equipment that can tolerate interruption of minutes. 4. Non-critical equipment
What does UPS stand for?
Uninterruptible Power Supply
What are the three main UPS systems?
Offline UPS, Delta Conversion, Single Conversion
For a static UPS, what are the most common batteries used?
Lead Acid
What is the purpose of a battery run down test?
To observe temperature, voltage, and current under load conditions and to test how long it takes for voltage decay
What code enforced by the State Fire Marshall requires anyone who operated Fuel Delivery Systems using a UST to obtain operating credentials?
EPA - 40-CFR 280
Name the four major components of the fuel delivery system?
Fuel storage, delivery system, monitoring system, and maintenance system
How much of the tank is required to be above ground for it to be classified as an above ground storage tank?
9-100%
How much of the tank is required to be below ground for it to be classified as a underground storage tank?
10-100%
What are the disadvantages of an Above Ground Storage Tank?
Requires pumps for all return fuel (pipes aren’t above the tank), space constraints, tanks/piping must be heat treated due to weather exposure, certain state/FED codes limit size
What are the disadvantages of an Above Underground Storage Tank?
Leaks harder to detect, early leak detection required, water pumps required, tanks and piping must be double lined, increased corrosion protection required, expensive to maintenance and operate, strict construction permits, maintenance, training, and emergency response, and state/FED regulations more strict
What is the biggest advantage of a Day Tank?
Redundancy if issues arise with main tank pumps or system. Also helps reduce strain on pump by reducing runtime during an emergency
What types of valves are required for fuel delivery systems according to the NFPA?
Quick Action Safety Fuel Cut-off with temperature sensitive element that melts during a fire
What is the most common way to heat fuel and oil to maintain operating temperature?
Electrical Heat Trace
What is the purpose of fuel polishing?
Removes moisture and sediment, and prevents fuel from becoming stagnant
A standby system is classified as an Alternate Power Source. When can a Standby System be classified as an Emergency or Legally Required Standby System?
When required by code or an enforceable administrative agency
What are the three important considerations in identifying a load as one requiring an Emergency Source of Power?
Nature of occupancy, criticality of load, length of time outage can be permitted without a hazard to occupants
What are the five safety concerns when performing maintenance on a generator system?
- Never wear loose clothing around it. 2. Stay clear of rotating and hot components. 3. Wear hearing and eye protection. 4. Be aware of high voltages. 5. Only qualified and trained personnel should work on them
Why would a standby generator system fail to start?
Oversight of people accountable for its maintenance
Load Bank Testing is important to test a generator system under a working load. What is the recommended length of time a generator should be load banked?
Approximately 4 hours or long enough for temperatures to stabilize in the engine/generator
What are Federal and State Codes for fuel storage meant to protect?
Prevent ground water supply contamination
What can happen to fuel and oil if it is exposed to freezing temperatures?
Coagulation of fuel, which could plug filters and fuel lines
Who is responsible for cleanup of any leaked fuel and oil?
The owner of the tanks
What devices should be used to monitor fuel and oil delivery equipment for failures?
Actuator End Switches and Flow Switches
What should you check for 24 hours after fuel have been delivered to the main tank?
Any signs of water or sediment
