PREGUNTAS DE FORMACIÓN PROFESSIONAL ENERGY MANAGER

EXAMEN DE COMPETENCIAS

PROFESSIONAL ENERGY MANAGER

1.- Active Energy Efficiency Using Speed Control

Pregunta 1

What is the main alternative to variable speed control in fan and pump applications?

a.-Changing to an interruptable tariff
b.-Reducing the operating hours of the equipment
c.-Using a valve or damper to adjust the flow
d.-None of the above

Pregunta 2

Electronic Variable Speed Drives

a.-Make starting and stopping operations smooth and controlled
b.-Minimize inrush currents
c.-Convert mains AC supply into a tunable frequency and voltage
d.-All of the above

Pregunta 3

Which of the following is the most common motor starting method available on the market under 10kW

(15Hp)?

a.-Direct-on-line
b.-Star/delta
c.-Soft starting
d.-None of the above

Pregunta 4

This starting method progressively increases the motor voltage so that the motor becomes strong enough to accelerate the load to rated speed without causing torque or current peaks.

a.- Direct-on-line
b.- Star/delta
c.- Soft starting
d.- None of the above

Pregunta 5

Which of the following drive and has very accurate speed and torque control?

a.-Gear box
b.- Frequency converter
c.- Eddy current
d.- Damper

Pregunta 6

Which of the following is an advantage of variable speed control?

a.-Controlled start and stop
b.-Accuracy
c.- Mechanical protection
d.- All of the above

Pregunta 7

Chokes, passive filters and C-less drives are used in conjunction with variable speed drives to reduce the effects of what?

a.-Harmonics
b.-Belts
c.-Linear loads
d.-Input shafts

Pregunta 8

Using variable speed drives, the highest potential energy savings can be found on

a.-C-less drives, DC chokes, and passive filters
b.-AC chokes, multi-pulse drives, and active filters
c.-Pumps, fans and compressors
d.- Hoisting, Conveyors, generators

Pregunta 9

Which of the following conditions have the potential to negate the value of a variable speed drive?

a.-Energy is very cheap
b.-Valves or dampers are normally set in a fully open position
c.-Payback period or internal rate of return that does not meet company financial criteria
d.-All of the above

Pregunta 10

An energy saving opportunity is identified on a fan installation. The flow from the fan can be reduced from 100% of nominal output to 75%. According to the affinity laws, how much power will be saved at this output, compared to the power used to supply 100% of the flow?"

a.-25%
b.-40%
c.-58%
d.-75%

2.- Boiler Types and Opportunities for Energy Efficiency

Pregunta 1

What are the two primary designs of boiler layouts?

a.-Condensing boiler and system boiler
b.-Longitudinal drum and cross drum
c.-Fire tube and water tube
d.-None of these answers

Pregunta 2

Which of the following is an advantage of fire tube boilers?

a.-Relatively inexpensive
b.-Easy to clean
c.-Compact in size
d.- All of these answers

Pregunta 3

Which of the following is an advantage of water tube boilers?

a.- Cost
b.-Ease of cleaning
c.-Large steam output capabilities
d.-Ability to replace tubes

Pregunta 4

Which of the following is an advantage of condensing boilers?

a.- Increased condensate recovery
b.- Lower needs for water treatment
c.-Heat recovery from water in flue gases
d.-Ability to replace tubes

Pregunta 5

Low pH is a problem in boilers because acids attack metal surfaces. High pH is not a problem because alkalines do not cause any adverse effects.

a.- True
b.- False

Pregunta 6

Which of the following is NOT a common water impurity?

a.- Suspended solids
b.- Dissolved solids
c.- Dissolved gases
d.- Substances that cause foam or scum
e.- None of these answers

Pregunta 7

What is the purpose of blowdown?

a.- To eliminate impurities that accumulate in boiler water with evaporation
b.- To clean scale off the boiler tubes
c.- To eliminate impurities from the boiler feedwater tank
d.- To release steam contaminated with impurities
e.- All of these answers

Pregunta 8

A "bottom blowdown" removes "mud" and sludge from the bottom of the boiler.

a.-True
b.- False

Pregunta 9

A ______________ boiler blowdown uses a calibrated valve and a blowdown tap near the boiler water surface to draw water from the boiler at a predetermined rate

a.-Manual
b.- Continuous
c.- Automatic
d.- All of the above

Pregunta 10

Which of the following are examples of energy efficiency measures that can be taken in order to save on boiler operational running costs?

a.-Variable speed drives
b.- Pre-heating combustion air by recovering heat from flue gases
c.- Heat recovery from surface water blowdown
d.- Pre-heating feedwater by recovering heat from flue gases using an economiser
e.- All of the above

3.- Building Controls I

Principio del formulario

Pregunta 1

The purpose of a building control system is to measure environmental data (E.g. temperature, humidity, pressure, or

flow rate), compare that data against predetermined standards and initiate a change in order to change or maintain current environmental conditions.

a.-True
b.- False

Pregunta 2

A simple ______________ is defined as one input to a controller housing the control logic, which provides an output to one controlled device.

a.- Control system
b.- Control loop
c.- Control function
d.- Reset module

Pregunta 3

What provides data to the controller?

a.- Input devices such as sensors or contact closures
b.- Direct digital control
c.- Closed loop
d.- Controlled variable

Pregunta 4

Which control system component interprets the input according to its control logic?

a.- Sensor
b.- Controller
c.- Output
d.- Controlled device

Pregunta 5

Which control system component is activated in order to change or maintain environmental conditions?

a.-Input
b.-Sensors
c.- Controlled device
d.-None of the answer choices

Pregunta 6

Which control system component is activated in order to change or maintain environmental conditions?

a.-Input
b.-Sensors
c.-Controlled device
d.-None of the answer choices

Pregunta 7

This is the type of control loop where the output has no effect on the controlling variable.

a.- Open
b.- Closed
c.-Cascading
d.- Direct Digital

Pregunta 8

Another name for a cascade control loop is:

a.- Analog control loop
b.- Reset control loop
c.- Manual control loop
d.- None of the answer choices

Pregunta 9

This is the type of control loop where the controlling variable is affected by the actions of the controlled device upon the controlled variable.

a.-Open
b.-Closed
c.-Cascading
d.-Direct Digital

Pregunta 10

This is the type of control loop used to modify the performance of closed control loops when required.

a.- Open
b.- Closed
c.- Cascading
d.- Direct Digital

Final del formulario

4.- Building Controls II

Pregunta 1

True or false? Sensors can be a weak link in a building control system because if the control system is getting a signal from a faulty sensor, the control system makes wrong decisions, which can result in wasted energy and wasted money.

a.-True
b.-False

Pregunta 2

Which of the following is true of thermistors?

a.-They are inexpensive
b.- They require a source of power
c.- They are consistent in their performance over time
d.- They have excellent resolution that allows them to be used where precision control is a requirement

Pregunta 3

Which of the following is true of temperature transmitters?

a.-They are inexpensive
b.-They have adequate resolution for commercial applications
c.-They do not deliver the performance required for critical applications requiring high accuracy
d.-They require a source of power

Pregunta 4

Temperature sensors are used to measure a variety of variables, including:

a.-Outside air temperature
b.- The occupied space temperature
c.- Various temperatures within the mechanical system
d.- All of the above

Pregunta 5

Direct sunlight on an outside air temperature sensor will give the controller a false sense of the actual ambient temperature when making decisions. For buildings located in the northern hemisphere, the _____ side of the building is the best place to locate the outside air temperature sensor.

a.-North
b.-South
c.-East
d.-West

Pregunta 6

To measure the temperature of fluid in pipes, normally a/n ____ is used.

a.-Humidity sensor
b.-Temperature transmitter sensor
c.-Immersion sensor with well
d.-Averaging sensor

Pregunta 7

_____ measure the relative level of moisture in the air, and are important in critical environments like libraries, labs and data centers.

a.-Humidity sensors
b.-Temperature transmitter sensor
c.-Immersion sensor
d.- Strap-on sensor

Pregunta 8

True or False? There are practical limits on the distance between a sensor and the controller. Manufacturers provide specific guidelines on how far a sensor can be located from the controller for accurate control.

a.-True
b.- False

Pregunta 9

Which of the following gases are relevant for monitoring in a building system?

a.-Carbon monoxide
b.-Carbon dioxide
c.-Refrigerants
d.-All of the above

Pregunta 10

This type of flowmeter measures the speed of the flow and uses the cross-sectional area to calculate the volume that has passed through.

a.-Differential pressure flow meter
b.- Positive displacement flowmeter
c.-Velocity flowmeter
d.- Mass meters

5.- Building Controls III

Pregunta 1

The value that the controller is aiming to achieve is called the:

a.- Set point
b.- Control point
c.- Offset
d.- Controlling variable

Pregunta 2

Floating control may be used to control an analog device. The process will increase or decrease the control signal to the device based on its current position and its operating range. When floating control is used to control an analog device, the signal will be a value within a range, for example, between 0% and 100%. "

a.-True
b.- False

Pregunta 3

Which of the following are digital responses?

a.-Proportional
b.-Proportional + Integral
c.-Proportional + Integral + Derivative
d.-All of the above
e.-None of the above

Pregunta 4

Two-position control always produces an analog response where the end device is either in an "on" state or off state. The controlled device is also analog.

a.-True
b.- False

Pregunta 5

What are the five control loop responses?

a.-Two-position response, floating response, proportional response, proportional plus integral, and proportional plus integral plus derivative response
b.-Two-position response, tri-state response, floating response, proportional response, and inverse response
c.-Tri-proportional response, integral response, derivative response, floating response and a programmed logic response
d.-None of the above

Pregunta 6

What is a differential and why are differentials needed in building controls?

a.-The differential is where the "deadband" or neutral zone occurs. It is needed to ensure the system differentiates between on and off.
b.-The differential is where the throttling range is maximized. Without a differential, the throttling range the actuator will hunt for the programmed logic, and not finding it, will eventually shut down.
c.-The differential is a characteristic of a two-position controller. It is the difference between the setting at which the controller operates at one position, and the setting at which it changes to the other position. This is needed to prevent the controller from rapidly cycling off and on, also known as "hunting".
d.-None of the above

Pregunta 7

A tri-state device can accept one of three input signals. What are the possible responses?

a.-Clockwise rotation, counter-clockwise rotation, or remain stationary
b.-Open a contact, close a contact, or sound an alarm
c.-Increase proportional response, add integral response, add derivative response
d.-None of the above

Pregunta 8

The difference between the actual value and the value that the controller is aiming to achieve is called the.

a.-Error-Offset
b.-Differential
c.-Setpoint-Control point
d.-None of the above

Pregunta 9

What is the throttling range?

a.-The throttling range refers to the precision with which an actuator may be positioned, e.g. in increments of 10%
b.-The throttling range is the amount of change in the controlling variable required to run the actuator of the controlled device from one end of its stroke to the other end.
c.-The throttling range is the set of outputs that inversely correspond to the deadband of a floating response.
d.-None of the above

Pregunta 10

Stability is achieved when the controller has obtained the desired value with zero offset.

a.-True
b.-False

6.- Building Controls IV

Pregunta 1

Which of the following statements, regarding the two position control response, are true?

a.-A two-position control response is the simplest kind of response that can be made from a controller.
b.-When a certain condition is met, the controller enables a digital output to be turned "on".
c.-When a second certain condition is met, the controller disables that digital output, or turns it "off."
d.-All of the above
e.-None of the above

Pregunta 2

What is the definition of the "differential"?

a.-The differential is the difference between the setting at which the controller operates at one position, and the setting at which it changes to the other position.
b.-The differential is the range of inputs for which the controller output does not change, even if the input changes.
c.-The differential is either on or off, 1 or 0, yes, or no...nothing in between.
d.-None of the above

Pregunta 3

Imagine a temperature control system with a differential of 3 degrees. What would occur if the actual value was 1 degree warmer than the setpoint?

a.-The system would supply warm air to the zone
b.-The system would supply cool air to the zone
c.-Nothing
d.-None of the above

Pregunta 4

Why is it important to have a "neutral zone" (or "deadband") when employing a floating control system?

a.-A "neutral zone" or "deadband" ensures that the system operator can decide whether or not to accept a request from a user.
b.-A "neutral zone" or "deadband" ensures control devices from different manufacturers are compatible.
c.-A "neutral zone" or "deadband" ensures the actuator does not respond when the actual value is within an acceptable range of the setpoint - avoiding overuse.
d.- None of the above

Pregunta 5

Stability is achieved when the control point is within the throttling range.

a.-True
b.-False

Pregunta 6

Floating control may be used to control an analog device. The process will increase or decrease the control signal to the device based on its current position and its operating range. When floating control is used to control an analog device, the signal will be a value within a range, for example, between 0% and 100%.

a.-True
b.-False

Pregunta 7

What is the chief benefit of floating control?

a.-Greater complexity-but more efficiency in a system
b.-Greater simplicity in a system
c.-Greater stability in a system
d.-All of the above
e.-None of the above

Pregunta 8

The throttling range is the range of inputs that translate into the full range of travel of the actuator.

a.-True
b.-False

Pregunta 9

What are the effects of selecting a small or large deadband?

a.-A small deadband helps to keep the system close to setpoint. A large deadband improves stability.
b.-A small deadband defines a tight tolerance to setpoint. A large deadband helps to prevent the system from "hunting" and making many small adjustments while trying to achieve the setpoint.
c.-With a small deadband, actuators will tend to make more adjustments to maintain actual values close to setpoint and will wear out more quickly. With a large deadband actuators will operate less and their life is increased
d.-All of the above
e.-None of the above

Pregunta 10

The neutral zone is the range over which the output of the controller remains constant as the input varies.

a.-True

b.-False

7.- Building Controls V

Pregunta 1

Which of the following statements is true regarding the proportional control response?

a.-Proportional control is a simple and widely used method of control for many kinds of systems.
b.-Proportional control involves giving a response proportional to the stimulus by addressing how far from set-point the variable is.
c.-Proportional control follows one simple rule, "For every degree of temperature difference from the setpoint, increase the airflow by a certain amount".
d.-All of the above
e.-None of the above

Pregunta 2

The proportional response is concerned with

a.-The present offset
b.-Accumulation of past offsets
c.-Prediction of future offsets
d.-None of the above

Pregunta 3

The integral response is concerned with

a.-The present offset
b.-Accumulation of past offsets
c.-Prediction of future offsets
d.- None of the above

Pregunta 4

The derivative response is concerned with

a.-The present offset
b.-Accumulation of past offsets
c.-Prediction of future offsets
d.- None of the above

Pregunta 5

On a graph of actual over time, the integral is represented by the area under the graph.

a.-True
b.-False

Pregunta 6

On a graph of actual over time, the derivative is represented by the slope of the line.

a.-True
b.-False

Pregunta 7

When is it especially useful to avoid overshooting the setpoint?

a.-In a building where cooling towers are employed to increase the refrigeration effect. If the cooling tower is overused due to overshooting the setpoint, there will be an impact on the water bills and fan energy consumption.
b.-In a building where cooling is enabled but heating is disabled. If the zone is overcooled due to overshooting the setpoint, users will have to wait for the space to heat back up passively.
c.-In a building where waste heat recovery is used to provide domestic hot water. If the zone is overheated due to overshooting the setpoint, insufficient waste heat may be available.
d.-None of the above

Pregunta 8

What's the value of adding the derivative?

a.-The derivative term changes the total response if the actual value is falling or rising quickly. This makes the change more gradual and helps avoid overshooting the setpoint.
b.-The derivative calculation increases the range of inputs for which the controller output does not change, even if the input changes.
c.-The derivative term changes the total response if the actual value has been away from setpoint for a long time. This makes the change even faster in order to achieve setpoint in a timely manner.
d.-All of the above

Pregunta 9

When determining appropriate uses for P-I-D, what is the first key component to determine?

a.-Cost-how much you can spend
b.-Time-how long the control system takes to detect a change
c.-System placement
d.-None of the above

Pregunta 10

Select the appropriate response for a control situation where for every degree of temperature offset from the setpoint, the response must be increased by a fixed amount.

a.-Proportional
b.-Integral
c.-Derivative
d.-Floating

8.- Building Controls VI

Pregunta 1

The purpose of tuning a system is to adjust the response to best meet the load conditions

a.-True
b.-False

Pregunta 2

Name two ways of handling setpoint adjustments without incurring large swings in the control response

a.-Include an integral term in the control response, or adjust the gain of the system
b.-Include a derivative term in the control response, or make the setpoint adjustment gradually
c.-Incorporate floating control with a wide deadband, or two-position control with a narrow differential
d.-None of the above

Pregunta 3

Although PID control can be expensive, it is the best overall control strategy for any building control situation.

a.-True
b.-False

Pregunta 4

What is the advantage of reduced gain?

a.-There is no advantage, because reduced gain causes actuators to wear out more quickly ← Respuesta incorrecta
b.-The system will be lower cost, because fewer controllers can be used
c.-The acceptable offset from the setpoint will be smaller. This makes it easier for the system to achieve stability
d.-The proportional response will be smaller, allowing for finer adjustments. This makes it easier for the system to achieve stability

Pregunta 5

PID control is not the best control strategy to minimize/eliminate overshooting a setpoint.

a.-True
b.-False

Pregunta 6

What happens when a system is tuned with proportional control for a light load (1-2 people, each with a laptop) and a meeting is held in that same space with 10 people, each possessing a laptop?

a.-There will be an increase in temperature at first, however the system will continue to send more and more air, and eventually the system will stabilize within an acceptable offset of the setpoint.
b.-There will be an increase in temperature, however the system will only push back a little. Since it isn't pushing back enough airflow, the temperature will continue to rise. The response will also continue to rise, sending more and more air, but it will never be enough for the space. This system will never stabilize, unless the load is reduced.
c.-The derivative calculation will notice that the temperature is increasing quickly, and will increase the response in order to achieve setpoint more quickly.
d.-None of the above

Pregunta 7

Building control systems often reach stability at an offset or error from the setpoint. What or who determines if that offset is acceptable?

a.-Customer needs
b.-Offsets are never acceptable
c.-The capability of the control system
d.-The engineer who programs the system

Pregunta 8

The integral component gets added to the longer that the system is away from setpoint. If I am above setpoint, a positive amount gets added. If I am below my setpoint, a negative amount gets added. If the integral component is positive or negative, it will be combined with the proportional component to increase or decrease the proportional response.

a.-True
b.-False

Pregunta 9

What type of response is the best fit for a moderate responding system with stable setpoints?

a.-Proportional
b.-Proportional + derivative
c.-Proportional + integral
d.-Proportional + integral + derivative
e.-None of the above

Pregunta 10

What type of response is the best fit for a fast responding system?

a.-Proportional
b.-Proportional + integral
c.-Proportional + integral + derivative
d.-Floating
e.-None of the above

9.- Building Controls VII

Pregunta 1

What is the main reason why a system using proportional control will reach stability with an offset?

a.-Proportional control is a poor method and is incapable of reaching setpoint.
b.-The offset is acceptable so there is no reason for the system to continue responding
c.-The load on the system at the time is matched by the tuning of the proportional response
d.-None of the above

Pregunta 2

What is the main reason why a system using proportional control will often oscillate before stabilizing?

a.-When the system detects an offset and responds by increasing the response, the actual value will approach the setpoint. The system may reduce the response as a consequence, and if the load is great enough the actual value will once again diverge from setpoint. This is repeated until stability is reached
b.-When the system detects that the offset is within the deadband range it will not make further adjustments to the response. The actual value will float within the deadband until stability is reached.
c.-When the system detects that the offset has exceeded the throttling range the variable is out of control.
d.- Variable is out of control. None of the above

Pregunta 3

Which of the following equations represents a proportional response?

a.-Output = deviation from setpoint * time * ga
b.-Output = (system load - offset) * gain
c.-Output = error * gain
d.-None of the above

Pregunta 4

In a PID control loop, what is the main intention of the proportional term?

a.-Respond to offsets and achieve stability within an acceptable offset from the setpoint
b.-Reduce the offset from the setpoint
c.-Achieve a value close to setpoint more quickly.
d.-None of the above

Pregunta 5

In a PID control loop, what is the main intention of the integral term?

a.-Respond to offsets and achieve stability within an acceptable offset from the setpoint
b.-Achieve stability at a reduced offset from the setpoint
c.-Achieve a value close to setpoint more quickly.
d.-None of the above

Pregunta 6

In a PID control loop, what is the main intention of the derivative term?

a.-Respond to offsets and achieve stability within an acceptable offset from the setpoint
b.-Achieve stability at a reduced offset from the setpoint
c.-Achieve a value close to setpoint more quickly
d.-None of the above

Pregunta 7

The integral term is based on the accumulation of errors (offsets) over time.

a.-True
b.-False

Pregunta 8

What is the effect of changing the gain of a system?

a.-Changes the response to an offset
b.-Increases the cost of the system
c.-Increases the likelihood of breakdown
d.-All of the above

Pregunta 9

Proportional control is a form of

a.-Linear response
b.-Logarithmic response
c.-Exponential response
d.-Regressive response

10.- Building Controls VIII

Pregunta 1

Which of the following is NOT a type of controller

a.-Primary controller
b.-Secondary controller
c.-Application-specific controller
d.-Systemic controller
e.-Network controller

Pregunta 2

The difference between a primary and secondary controller is:

a.-Secondary controllers have less memory
b.-Secondary controllers usually do not contain a time clock
c.-Secondary controllers have fewer I/O points
d.-All of the above

Pregunta 3

A variable air volume or VAV box controller is an example of

a.-A primary controller
b.-A secondary controller
c.-An application-specific controller
d.-None of the above

Pregunta 4

Which device is used in order to expand the number of inputs and outputs of a primary controller?

a.-An application-specific controller
b.-A point collection module
c.-A network controller
d.-None of the above

Pregunta 5

This type of controller can be used to translate and allow communications between devices with different communications protocols on the same system, such as converting between LON and Bacnet

a.-An application-specific controller
b.-A point collection module
c.-A network controller
d.-None of the above

Pregunta 6

This type of actuator is used in any application where only an open or closed position is desired

a.-Two-position
b.-Modulating
c.-Tri-state
d.-Pulse width modulation

Pregunta 7

______________ are most commonly used for enabling and disabling mechanical devices such as chillers and boilers, thermostats, fans, and pumps.

a.-Actuators
b.-Tri-state controllers
c.-Relays and contactors
d.-None of the above

Pregunta 8

Without this, a pump or fan would only be able to run at one speed, and that might not be the most efficient use of motor power.

a.-Modulating actuator
b.-Variable speed drive
c.-Secondary controller
d.-None of the above

Pregunta 9

An actuator that can receive instructions to "turn clockwise," "turn counter-clockwise," or "stay in current position" is called

a.-Two-position
b.-Modulating
c.-Tri-state
d.-Pulse width modulation

Pregunta 10

If a circuit is wired to a normally open relay:

a.-then it would not be a "made" or completed circuit until power was applied to the electromagnet

b.-then it would be a "made" or operable circuit when there is no power on the electromagnet, and a broken circuit when power is applied to the electromagnet
c.-Neither are true
d.-Both are true

11.- Compressed Air Systems I

Pregunta 1

Sound, energy efficient operating practices inside the compressed air system can lead to a significant reduction in costs and reduce energy consumption by 20% to 50%.

a.-True
b.- False

Pregunta 2

Optimization of the compressed air system can lead to:

a.-Reduced maintenance
b.-Less downtime
c.-Increased production and product quality
d.-All of the above

Pregunta 3

Why is compressed air a relatively inefficient source of power?

a.-60 to 80% of the power consumed to make compressed air is converted into heat
b.-60 to 80% of the power consumed to make compressed air is lost in friction and pressure drops
c.-60 to 80% of the power consumed to make compressed air is lost due to oil contamination
d.-60 to 80% of the power consumed to make compressed air is lost due to inefficient control methods such as throttling

Pregunta 4

Which of the following statements is NOT true.

a.-Gauge pressure is the sum of absolute pressure and atmospheric pressure
b.-Absolute pressure is measured compared to a perfect vacuum. Gauge pressure is pressure above atmospheric pressure.
c.-Gauge Pressure is the difference between absolute pressure and atmospheric pressure
d.-Atmospheric pressure is generally accepted as 1.013 bar a or 14.7 psi a.

Pregunta 5

A standard cubic foot and a standard cubic metre of air are compressed to one-eighth of their original volume. What is the result?

a.-0.125 standard cubic foot and 0.125 standard cubic metre of compressed air
b.-0.5 cubic foot and 0.5 cubic metre of free air delivered
c.- 1 standard cubic foot and 1 standard cubic metre of air if allowed to return to standard conditions
d.-None of the above

Pregunta 6

In a compressed air system, the supply side focuses on how compressed air is distributed and utilized for productive use, and the demand side deals with how compressed air of the required quality should be efficiently produced.

a.-True
b.- False

Pregunta 7

Why are compressed air systems overlooked as a source of energy efficiency savings?

a.-Systems are not well understood by plant operations staff
b.-Modifying a system is perceived as a risk to production
c.-Vendors compete in a market where equipment is typically sold on a "lowest first bid", without regard for the cost of operation
d.-All of the above

Pregunta 8

_____ is volume flow referenced from the conditions at the compressor inlet.

a.-Inlet flow
b.-Actual flow
c.-FAD
d.-Standard flow

Pregunta 9

Compressed air requirements include

a.-Cleanliness
b.-Dryness
c.-Oil content
d.-All of the above

Pregunta 10

Over the lifetime of a compressed air system, approximately _____ of the total cost of ownership is energy.

a.-20%
b.-40%
c.-60%
d.- 80%

11.- Compressed Air Systems II

Pregunta 1

True or False? There are two basic compressor types: Positive- dynamic and Displacement.

a.-True
b.- False

Pregunta 2

The selection criteria involved in choosing the proper compressor for your application could include:

a.-Capacity
b.-Efficiency at full, partial and no load
c.-Oil carry-over
d.-All of the above

Pregunta 3

This type of positive displacement compressor resemble a bicycle pump or piston, driven by a rod from a crankshaft and may be air-cooled or liquid-cooled.

a.- Reciprocating
b.-Rotary
c.-Centrifugal
d.- Axial

Pregunta 4

What is the advantage of multi-stage compressors?

a.-It is more efficient to bring compressed air to the required compression in stages, instead of doing it all in one stage
b.-It is easier to maintain a multi-stage compressor, because each stage can be worked on separately
c.-Multi-stage compressors have lower initial capital costs, because each of the stages can use smaller, less complex parts and designs
d.- Multi-stage compressors are more reliable, because if one stage fails the others can still keep working

Pregunta 5

What is a double-acting compressor?

a.-It is a compressor which combines rotary and reciprocating designs to achieve maximum efficiency
b.-It is a reciprocating compressor where both sides of the piston are used for compression, giving twice the capacity for a given cylinder size
c.-It is an axial compressor where both the rotor and the stator contribute to the compression effect
d.-It is another term for a two-stage compressor

Pregunta 6

This type of rotary compressor has a rotor with blades that fit inside radial slots. The rotor is fitted within the casing at an offset.

a.-Liquid Ring
b.-Sliding vane
c.-Screw compressor
d.-Rotary lobe blower

Pregunta 7

This type of rotary compressor uses a pair of meshed helical screws to force air or gas into a smaller space, thus compressing the element.

a.-Liquid Ring
b.-Sliding vane
c.-Screw compressor
d.-Rotary lobe blower

Pregunta 8

What is the most important measurement for practical comparisons of the energy efficiency of different compressors?

a.-Adiabatic efficiency
b.-Energy used per unit compressed air produced (e.g. kW per CFM or kW per CMH)
c.-Mechanical efficiency
d.-sothermal efficiency

Pregunta 9

This type of dynamic compressor include single-stage and multi-stage blowers and compressors, use one or more spinning impellers to transfer kinetic energy to a continuously flowing air stream, and have one to four stages (or more for high pressure applications).

a.-Reciprocating
b.-Rotary
c.-Centrifugal
d.-Axial

Pregunta 10

This type of dynamic compressor contains a rotor and a motionless stator with airfoils that work together to raise air pressure through each stage of compression and generally have multiple stages.

a.-Reciprocating
b.-Rotary
c.-Centrifugal
d.-Axial

12.- Compressed Air Systems III

Pregunta 1

The most simple and effective method of control is simply turning the compressor on and off. Why isn't every compressor controlled this way?

a.- One cannot turn off large compressors and re-start them often as this can prematurely cause electric motor failure.
b.-The "hardware/software" expenditure to implement this type of control method is cost prohibitive.
c.-Turning on and off a compressor results in poor compressor performance at part load for many types of compressors.
d.-All of these answers
e.-None of these answers

Pregunta 2

Which of the following is a common method of compressor control?

a.-Automatic start-stop
b.-Variable speed control
c.-Dual or automatic dual
d.-Load-unload control
e.- All of these answers

Pregunta 3

Which control method is typically the most energy-efficient method to meet variable loads?

a.-Load-unload control
b.-Inlet modulation
c.-Variable speed control
d.-Discharge blow-off
e.-Variable volume ratio

Pregunta 4

Which control method is typically the least energy-efficient method to meet variable loads?

a.-Load-unload control
b.-Inlet modulation
c.-Variable speed control
d.- Variable volume ratio

Pregunta 5

Can throttling be applied to a centrifugal compressor?

a.-Throttling should never be used on a centrifugal compressor because of the risk of unstable flow and the potential for compressor damage.
b.-Throttling should never be used on a centrifugal compressor because it is the most inefficient control method. Discharge blow-off should be used instead.
c.-A centrifugal compressor can be throttled to some extent, but will reach the surge limit, where the compressor cannot overcome the pressure rise required. At his point the compressor has to be unloaded.
d.-A centrifugal compressor can be throttled across a wide range of required duties with virtually no limitations.

Pregunta 6

What are the different methods of Constant Speed Control?

a.-Load-unload two-step control
b.-Variable displacement and step-control
c.-Inlet modulation
d.-All of the above
e.-None of the above

Pregunta 7

A lead compressor is used to fulfil base load requirements while other trim compressors are brought online when needed to meet short-term peaks. This method avoids having a single large compressor which may operate efficiently during short-term peaks but which operate inefficiently at part load all the rest of the time. What is the name of this strategy?

a.-Sequencing
b.-Baselining
c.-Trimming
d.-Suction throttling
e.-Inlet modulation

Pregunta 8

Which of the following is a simple method of coordinating multiple compressors?

a.-Multiple stage inlet modulation.
b.-Cascaded pressure band control
c.-Dual control
d.-Modified control
e.-Load-unload two-step control

Pregunta 9

Which of the following control methods are commonly used with reciprocating compressors?

a.-Outlet guide vanes
b.-Adjustable inlet stator blades
c.-Suction throttling
d.-Demand response
e.-None of these answers

Pregunta 10

Inlet guide vanes can be used to control capacity on:

a.-Scroll compressors
b.-Reciprocating compressors
c.-Axial compressors
d.-Centrifugal compressors
e.-All of these answers

12.- Compressed Air Systems IV

Pregunta 1

In the supply side of the system, this component filters particulate and water of incoming ambient air:

a.-Air inlet filter
b.-Coalescing filter
c.-Adsorption filter
d.-All of these answers

Pregunta 2

Air compressors can be most efficiently operated at part load. A receiver stores air from the compressor so that it can be operated at part load for extended periods.

a.-True
b.-False

Pregunta 3

The four types of dryer that are commonly used on compressed air systems are:

a.-Ambient, latent, refrigerant, desiccant
b.-Deliquescent, refrigerant, desiccant, heat of compression
c.-Desiccant, vapor-compression, adsorption, coalescent
d.-Centrifugal, sensible heat, desiccant, absorbent

Pregunta 4

In the supply side of the system, this component cools compressor discharge air and condenses up to 70% of the

moisture drawn draw into the compressor.

a.-Automatic Drain
b.-After-Cooler
c.-Separator
d.-Primary Receiver

Pregunta 5

True or false? Manual valves are always encouraged as a way to drain liquid condensate from the traps that capture it.

a.-True
b.-False

Pregunta 6

The regeneration cycle for desiccant dryers can be done in a number of ways. Which is these is the MOST efficient method?

a.-Heat of Compression
b.-Heated Blower Purge
c.-Heated Exhaust Purge
d.-Pressure-Swing Heatless Method

Pregunta 7

Which of the following is NOT likely to improve the efficiency of the compressed air system:

a.-Changing manual valves to zero-air-loss traps
b.-Installing a twin-tower desiccant dryer instead of a refrigerant dryer
c.-Installing a pressure / flow controller between supply and demand sides of the system
d.-Increasing receiver capacity

Pregunta 8

True or false? The supply-side is normally where ambient air is processed into a pressurized, dry, clean form that can be used for many useful tasks. The demand side is the portion of the plant where air is distributed, final-filtered, regulated, and perhaps lubricated for a productive end use.

a.-True
b.-False

Pregunta 9

Desiccant dryers can achieve dew points below the freezing point of water. The pressure dew point is the temperature at which condensation or frost will first occur in piping.

a.-True
b.-False

Pregunta 10

Which of the following is used to remove lubricant oil from the compressed air?

a.-Cold coalescer
b.-Particulate filter
c.-Moisture separators
d.-Aftercooler

13.- Compressed Air Systems V

Pregunta 1 (Ponderación 10%)

The demand side of the compressed air system includes:

a.-The primary receiver, and the pressure / flow controller if present
b.-Text of Distractor
c.-One or more air compressors, and various aftercoolers
d.-Traps, drains, filters and dryers
e.-Components after the primary receiver, and the pressure / flow controller including the distribution and storage components, and end use equipment

Pregunta 2

True or False? Compressed air systems which are well maintained do not benefit from metering.

a.-True
b.- False

Pregunta 3

Which of the following is a good practice for design of the air distribution system?

a.-The length of the network should be kept to a minimum to reduce pressure drop
b.-The piping should have a large enough diameter to minimize pressure drop
c.-Piping should slope to allow for drainage of condensate and include traps for its removal
d.-All of the above

Pregunta 4

Over the life of a compressed air system, energy accounts for ____of the Total Cost of Ownership compared to just____ for the initial cost of capital.

a.-60%, 7%
b.-70%, 8%
c.-80%, 9%
d.- 90%, 10%

Pregunta 5

What data is required to calculate the annual operating cost of a compressor?

a.-Shaft power, operating hours, unit cost of electricity, operating level and percent of operating time, percentage of full load power used, motor efficiency
b.-Shaft power, operating hours, unit cost of electricity, motor efficiency
c.-Shaft power, operating hours, unit cost of electricity, motor efficiency, total air production
d.-Shaft power, operating hours, unit cost of electricity, motor efficiency, initial purchase price, maintenance costs

Pregunta 6

New, clean filters typically cause a pressure drop that consumes _____ of compressor energy. The pressure drop should be monitored over time to determine the optimal time to change filters.

a.-1-2%
b.-2-3%
c.- 3-4%
d.- 4-5%

Pregunta 7

A compressed air system is being operated at higher than needed pressure. The two primary effects of this are:

a.-The compressor will run hotter which could require additional cooling, and the air dryer will consume less energy
b.-The compressor consumes more energy than needed, plus every air leak or unregulated use will consume more air
c.-The compressor will consume more energy, but end use tools will operate more efficiently

d.- The primary receiver will fill more quickly which could require additional capacity, and desiccant used in dryers will need to be replaced more frequently

Pregunta 8

What is the approximate breakdown of cost for air production, drying, and filtering on the supply-side of a compressed air system when brand new and in steady efficient operation?

a.-61% compressor, 26% drying plus loss, 13% filter loss
b.-71% compressor, 16% drying plus loss, 13% filter loss
c.-81% compressor, 10% drying plus loss, 9% filter loss
d.- 91% compressor, 6% drying plus loss, 3% filter loss

Pregunta 9

A typical component of demand, _________, is/are defined as excess volume of air consumed by unregulated end uses as a result of supplying higher pressure than necessary for the point-of-use applications.

a.-Actual production needs
b.-Leaks
c.-Inappropriate uses
d.-Artificial demand

Pregunta 10

The compressor discharge pressure should be set as low as possible while still meeting the end use requirements. Reducing the pressure by 140 millibar or 2 psi saves approx _____ of energy consumed by the compressor.

a.-1%
b.- 2%
c.-3%
d.-4%

13.- Compressed Air Systems VI

Pregunta 1

What are the benefits of completing a block diagram for your compressed air system?

a.-It identifies all the components in the system
b.-It ensures that you know what all the components are, and can ensure they are adequately covered by preventative maintenance plans, and replacement provisions as necessary
c.-It identifies all the points of use which allows you to analyze the appropriate use of the expensive compressed air
d.-All of the above

Pregunta 2

A properly designed system should have a pressure loss of much less than ______ of the compressor's discharge pressure, measured from the receiver tank output to the transmission system.

a.-2%
b.-10%
c.-20%

d.-Depends on altitude

Pregunta 3

The type of appropriate compressor control strategy specified for a given system is largely determined by

a.-The type of compressor being used
b.-The facility's demand profile
c.-Both a and b
d.-Neither a nor b

Pregunta 4

Which of the following is a good practice to reduce the impact of leaks?

a.-Valve off abandoned lines because leaks can occur even when there is no equipment connected
b.-Inspect compressed air lines and carry out a periodic leak survey with an ultrasonic leak detector
c.-Keep the system pressure to the minimum level required by the end use equipment
d.-All of the above

Pregunta 5

________ items can be implemented quickly for immediate savings and improved system reliability. Implement maintenance at prescribed intervals for compressors, dryers, filters, traps, control valves, and meters.

a.-Preventative maintenance
b.-Predictive maintenance
c.-Breakdown maintenance
d.-Periodic maintenance

Pregunta 6

Since compressed air is such an expensive utility, leaks can be a very costly source of wasted energy in an industrial compressed air system. It's not unusual to find ____ of compressor output wasted in a good system, ____ in an average one, and ____ or more leakage in a poorly maintained system.

a.-2%, 6%, 8%
b.-5%, 8%, 15%
c.-10%, 20%, 30%
d.- 30%, 40%, 50%

Pregunta 7

It is important to fix leaks in your compressed air system because:

a.-Leaks waste energy and cause a drop in system pressure, which can make air tools function less efficiently, adversely affecting production
b.-Leaks shorten the life of almost all system equipment (including the compressor package itself)
c.-Leaks can lead to adding unnecessary compressor capacity
d.-All of the above

Pregunta 8

What is a potential alternative to compressed air for open blowing?

a.-Low pressure blowers and fans
b.-Brooms and brushes
c.-Nozzles
d.- All of the above

Pregunta 9

Which of the following are potentially inappropriate uses of compressed air

a.-Pneumatic screwdrivers and drills
b.-Padding, dilute-phase transport, and sparging
c.-Air powered torque drivers and actuators
d.-None of the above

Pregunta 10

Compressors convert 80% to 90% of their incoming energy to heat. ______ of this can be recovered and used for thermal energy.

a.-10% to 30%
b.-20% to 50%
c.-40% to 80%
d.- 50% to 90%

14.- Distributed Generation

Pregunta 1

What are the main benefits and issues for combustion turbines?

a.-Combustion turbines have relatively low emissions, low installation costs, and infrequent maintenance requirements. However, their low electric efficiency has limited turbines to serving peaking unit and combined heat and power (CHP) applications.
b.-Combustion turbines have relatively low emissions, low installation costs, and infrequent maintenance requirements. However, combustion turbines cannot be used for serving peaking unit and combined heat and power (CHP) applications due to their need for recuperated energy.
c.- Combustion turbines have relatively high electric efficiencies. However, their relatively high emissions, high installation costs, and frequent maintenance requirements make them a concern.
d.- Combustion turbines are the perfect solutions for distributed generation, since they produce no emissions, have low installation costs and no maintenance requirements. They have the highest electrical efficiency and may also be used for combined heat and power applications in remote areas.

Pregunta 2

What are the advantages and disadvantages of photovoltaics?

a.-PV systems require no fuel supply, are completely silent, require little maintenance, have a long shelf life, and are excellent for load balancing. However, they have a high initial cost and the system components are expensive to replace. PV systems require a skilled labor force to create, and may require the use of toxic materials such as Cadmium. PV systems are intermittent and only produce electricity when the sun is shining, so storage batteries or a secondary power source is needed.
b.-PV systems are inexpensive to create/install, and the system components are inexpensive to replace; PV systems require no fuel supply, require little maintenance, have a long shelf life, and are excellent for load balancing. However, they can become quite noisy; and may require recuperation; they must be used in populated areas, and are not suitable for remote applications.
c.- PV systems are inexpensive to create/install, and have short construction times; PV systems have automated operation, as well as quick load changes. However, PV systems require a specialized fuel supply, have high maintenance requirements, have a short shelf life, and do not allow for effective load balancing. PV systems are not suitable for remote applications.
d.-PV systems have no known advantages. However, disadvantages include expense to operate and install, toxicity to environment while operating, noise, and reliability has been low.

Pregunta 3

Which of the following has the longest start-up time from a cold start?

a.-Diesel engine power plant
b.-Conventional steam power plant
c.-Combined gas turbine and steam turbine
d.- None of the above

Pregunta 4

Place these distributed generation technologies in order of overall efficiency - from highest to lowest.

a.-Photovoltaics, Stirling engine, Combustion gas turbine, Microturbine Photovoltaics
b.-Combustion gas turbine, Microturbine, Stirling engine, Photovoltaics
c.-Microturbine, Stirling engine, Photovoltaics, Combustion gas turbine
d.-Stirling engine, Photovoltaics, Microturbine, Combustion gas turbine

Pregunta 5

What are the primary categories of technology used to generate small-scale electricity?

a.-Engine generator sets, microturbines, combustion gas turbines, steam turbines, wind turbines, and

b.-Engine generator sets, macroturbines, nuclear turbines, coal-fired turbines, wind turbines, and photovoltaics
c.-Engine generator sets, microturbines, jet-engine turbines, fog turbines, satellite turbines, solar turbines
d.-None of the above

Pregunta 6

What are the emerging technologies for distributed generation?

a.-Fuel cells, nuclear turbines and photovoltaics
b.-Stirling engines and vertical wind turbines
c.-Fuel cells, photovoltaics, and wind turbines
d.-Fuel cells and Stirling engines

Pregunta 7

Dispersed Power is the use of small-scale power generation technologies located close to the load being served. In most cases, dispersed power with energy recovery provides multiple streams of energy - cleanly and efficiently.

a.-True
b.-False

Pregunta 8

Recent electricity market deregulation, greater emphasis on environmental quality, and on-going concerns related to the high cost of electricity is resulting in a renewed interest for distributed generation throughout the world.

a.-True

b.-False

Pregunta 9

Distributed generation increases energy losses by moving energy production further away from the end user. Distributed generation increases the number and size of transmission and distribution wiring needed to serve modern-day energy needs.

a.-Trueb.-False

Pregunta 10

Most microturbine units are designed for continuous-duty operation and many are recuperated to reduce fuel consumption. How does recuperation affect efficiency and heat recovery?

a.-A recuperated unit will decrease fuel efficiency, but provides for an increase in heat available for recovery and other uses
b.-A recuperated unit will not affect fuel efficiency, but provides for an increase in heat available for recovery and other uses
c.- A recuperated unit will increase the fuel efficiency, but leaves less heat available for recovery for other uses
d.- A recuperated unit will increase the fuel efficiency, and increases the heat available for recovery and other uses
e.-None of the above

15.- Energy Audits

Pregunta 1

What are the four steps of an audit?

a.-Kick-off; On-site inspection; Data analysis; Results restitution
b.-Initial meet and greet; site analysis; Projected timeline for completion; Deficiency identification; Results restitution
c.-Kick-off; Analyzing head-count; Projecting savings; On-site inspection
d.- Planning; Preparation; Prioritization; Pay-off

Pregunta 2

What are the three things an energy audit will tell you?

a.-Projected energy consumption; projected priorities; potential to save energy
b.-Current cash flow; projected cash flow; projected financing costs
c.-Current energy consumption; projected cash flow; help with prioritizing actions
d.-Current energy consumption; potential to save energy; help with prioritizing actions

Pregunta 3

If you wanted to obtain a detailed evaluation of the energy saving opportunities at your site, which audit would you choose?

a.-Comprehensive
b.-Walkthrough
c.-Investment grade audit
d.-Financial audit

Pregunta 4

Which of the following would be covered in a typical energy audit?

a.-Pumping, Ventilation, Lighting, Compressed Air
b.-Steam, Refrigeration, HVAC, Vacuum, Process Machinery
c.-Controls, Operations, Maintenance, Employee Awareness
d.-All of the above
e.-None of the above

Pregunta 5

What are the two areas to focus on when preparing for an energy audit?

a.-Access to the audit instruments
b.-Commonly required data
c.-Planning the audit activities to include participation of the necessary people from the facility
d.-A and B
e.-B and C

Pregunta 6

How does the facility operating profile help the auditor?

a.-Shows the budget available for investment in energy efficiency programs to help the auditor tailor the report
b.-Shows the days and times that the plant is operating to help the auditor understand usage patterns and analyze rate options
c.-Shows the availability of operators and technicians for interviews during the audit
d.-All of the above

Pregunta 7

Every audit will culminate with an audit report. What should be included in an audit report?

a.-Executive Summary; Energy Cost Projections; Energy Management Priorities; Energy Action Plan Results
b.-Executive Summary; Energy Cost Analysis; Energy Management Recommendations; Energy Action Plan
c.-Executive Summary; Audit Effectiveness Analysis; Energy Management Priorities; Energy Action Plan Results
d.- None of the above

Pregunta 8

An "Action Plan" will provide ways to manage and control power consumption and costs, as well as propose energy

savings solutions.

a.-True

b.- False

Pregunta 9

What are the four activities the auditor performs?

a.-Understanding the site and gathering the data; Measuring/Monitoring/Testing; Assessing the situation, and Proposing an action plan
b.-Understanding the site and gathering the data; Documenting waste; Data analysis; Testing the water for wastefulness
c.-Assessing the situation; Measuring; Monitoring/Testing; preparing audit report for the client
d.-Conducting a walkthrough; Employing questionnaires; Documenting and assessing; Proposing an action plan

Pregunta 10

Follow-up actions are necessary to benefit from the audits and drive continuous improvements for the site. Which of the following are follow-up actions to an audit?

a.-Review the energy action plan; Establish an implementation schedule; Measure the energy saving goals; Approve the action plan; Compare audit performance over time; Seek additional opportunities to include valued people
b.-Validate the energy action plan and the implementation schedule; Measure the energy saving goals; Approve the action plan; Measure the audit goals; Set a baseline and compare the performance over time; Seek additional audit opportunities
c.-Validate the energy action plan and the implementation schedule; Define the energy saving goals; Implement the action plan; Establish indicators for measuring the fulfillment of the goals; Set a baseline and compare the performance over time; Seek additional opportunities for continuous improvement
d.-None of the above

16.- Energy Audits Instrumentation I: Electrical, Lighting, Temperature and Humidity Measurement

Pregunta 1

Light measurements should be taken to assess that lighting conditions are adequate for the space. To ensure proper measurements, which condition(s) should be met for accurate readings?

a.-Measure the lighting levels at each task site
b.-Measure the lighting levels at the working surface in a horizontal plane, 76.2 centimeters (30 inches) above the floor
c.-Measure the lighting levels with the full use of interior shading to reduce direct solar gain
d.-All of the above

Pregunta 2

Which type of hygrometer provides the most precise readings of relative humidity?

a.-Cooled mirror dew point hygrometer
b.-Aspirated psychrometer
c.-Hair tension hygrometer
d.- Sling pyrometer
e.-Any of the above, as they will all provide equally precise measurements

Pregunta 3

To measure current properly, the ammeter needs to be placed in series with the element (resistor, bulb, battery) that we are measuring.

a.-True
b.-False

Pregunta 4

Thermocouples are very simple and durable temperature sensors. Name two common applications of thermocouples.

a.-Measuring room temperature and monitoring the presence of a pilot light
b.-Spot checking refrigerators and ovens
c.-Measuring objects that are electrically active and too dangerous to touch
d.-Measuring relative humidity at very low and very high ranges

Pregunta 5

Name the instrument used for measuring the electrical potential difference between two points in an electric circuit.

a.-Psychrometer
b.-Power Factor Meter
c.-Ohmmeter
d.-Voltmeter

Pregunta 6

An RTD measures temperature by measuring the change in electrical resistance across a metal wire.

a.- True

b.-False

Pregunta 7

Which of these instruments are used for measuring relative humidity?

a.-Psychrometer, Hair Tension Hygrometer, Electronic Hygrometer
b.-Luxometer, Ohmmeter, Thermometer, Surface Pyrometer, Sling Speedometer
c.-Manometer, Hydrometer, Pedometer
d.-A and B
e.-B and C

Pregunta 8

A dual bimetal thermometer provides readings in both Celsius and Fahrenheit. What are some common energy audit applications for dual bimetal thermometers?

a.-Checking ambient air temperature
b.-Checking the temperatures of refrigerators, walk-in coolers and ovens ← Respuesta incorrecta
c.-Checking HVAC systems
d.-All of the above

Pregunta 9

Humidity recorders allow you to track the level of humidity in a given location for a defined period of time. Which type of humidity recorder is the most appropriate to use in a remote location for an extended period of time?

a.-Paperless recorder
b.-Circular recorder
c.- Datalogger
d.-Flatbed recorder

Pregunta 10

With this type of temperature measuring instrument, an infrared thermometer senses emitted, reflected, and transmitted energy from an object and translate this information into a temperature reading. Name this instrument.

a.-Surface pyrometer

b.-Dual bimetal thermometer
c.-Surface thermometer
d.-Infrared psychrometer