Ricardos 6th test
T/F A sudden drop in a resistance measurement of a motor such as 100 megohms to 2 megohms over a six-month period is an indication of a problem, even when the measurement is above the accepted value.
True
T/F In an electrical system, the ground removes any leakage current from exposed non-current-carrying metal parts and directs any high fault current to ground
True
T/F It is important to use as few connections as possible because excessive connections lower system performance.
True
T/F Modern requirements for communications include the need to communicate over great distances as accurately and quickly as possible
True
T/f One way of correcting the power factor is to add capacitor banks to the power lines.
True
T/F A preventative maintenance program is a combination of unscheduled and scheduled maintenance work required to maintain equipment in peak operating condition.
True
T/F Product testing can be of the nondestructive or destructive type.
True
T/F The advantage of using a microwave link is that a microwave link allows reliable communication regardless of rain, fog, or other atmospheric conditions that can distort other wireless signals (laser and radio waves).
True
T/F A noncontact voltage detector is a test instrument that indicates the presence of voltage without displaying the actual amount of voltage present.
True
T/F True RMS test instruments can measure non-sinusoidal waveforms (distorted sine waves) produced by nonlinear loads
True
T/F Typically any voltage above 50 VAC is considered an electrical shock hazard.
True
T/F VDV signals are transmitted using any combination of hard wiring (cable), fiber optic cables, or wireless (laser and satellite) devices.
True
T/F When testing for voltage variations, all loads that may be on during peak usage should be turned on (or the test should be run during peak usage times).
True
T/F When voltage unbalance improves as loads are removed, the problem is inside the facility.
True
Why is it desirable to take conductor insulation tests over time? a. Conductor failure (or expected life) can be predicted. b. Conductor insulation failure (or expected life) can be predicted. c. It costs less to perform multiple tests. d. It is nonproductive to repeat conductor insulation tests over time.
a. Conductor failure (or expected life) can be predicted.
___is a method of using light to transport information from one location to another through thin filaments of glass or plastic a. Fiber optics b. Internet Protocol (IP) c. Transmission Control Protocol (TCP) d. Wireless
a. Fiber optics
Which of the following is not a common cause of single-phasing? a. Blown fuses b. Harmonic distortion c. Lightning strike on one of the power lines [Use as written] d. Mechanical failure within switching equipment
b. Harmonic distortion
Most wireless communication systems use low-power radio or ______ . a. fiber optics b. infrared frequencies c. low bandwidth frequencies d. ultra high frequency lasers
b. infrared frequencies
Megohmmeters and some hipot testers are also called ___ . a. capacitance testers b. insulation testers c. thumpers d. voltmeters
b. insulation testers
A(n) _____ load is any load in which current increases proportionately as voltage increases and current decreases proportionately as voltage decreases. A _____ load is any load in which the instantaneous load current is not proportional to the instantaneous voltage. a. electrical / mechanical b. linear / nonlinear c. linear / rotary d. nonlinear / linear
b. linear / nonlinear
A(n) ____ wire is any conductor (cable or wire) that has an unwanted low resistance path between two conductors or to ground. a. open b. shorted c. split d. all of the above
b. shorted
A(n) ? is used to test for noise problems. a. DMM b. harmonic analyzer c. oscilloscope d. TDR
c. oscilloscope
It is important to check a high voltage detector on a known (energized) voltage source or ___ verifier before taking a measurement on an unknown voltage source. a. energized fault b. high voltage c. piezo d. visual
c. piezo
A ____ reads the size, shape, and return time of reflected pulses to identify the type of problem. a. cable fault locator b. oscilloscope c. SWR meter d. Time Domain Reflectometer
d. Time Domain Reflectometer
___ is a logical, step-by-step process used to find a problem in an electrical power system or process as quickly and easily as possible. a. Preventive maintenance b. Relay Logic c. Shotgun approach d. Troubleshooting
d. Troubleshooting
A(n) ____is a high-resistance ohmmeter used to measure the insulation deterioration on various wires by measuring high resistance values during high voltage test conditions. a. dielectric absorption meter b. ground continuity tester c. hipot d. megohmmeter
d. megohmmeter
A(n) _____ is an instrument that graphically displays an instantaneous voltage (trace). a. Analog multimeter b. DMM c. frequency counter d. oscilloscope
d. oscilloscope
A(n) _____ test is a test that measures the time, (in nS), required for a signal to travel the length of a cable pair. a. attenuation b. delay skew c. NEXT d. propagation delay
d. propagation delay
Knowing the length of VDV cable is important because VDV cable, like all conductors, has __ that reduces the amount of power passed through the cable. a. conductivity b. copper c. insulation d. resistance
d. resistance
The primary source of voltage unbalance that is less than 2% is ? load(s) on a three-phase circuit a. capacitive b. more than one three-phase c. resistive three-phase d. single-phase
d. single-phase
T/F Transient voltages differ from voltage sags and voltage swells by being smaller in magnitude and longer in duration, having a steep rise time, and being erratic.
False
T/F Fiber optic cables do not allow for expansion and contraction during temperature changes (not including freezing).
False
T/F Harmonic distortion will be the least when measured at individual nonlinear loads and will be greatest at the main panel.
False
T/F Insulation has the lowest resistance when first placed into service on conductors and electrical devices.
False
T/F It is acceptable to run communication cables in parallel with power cables.
False
T/F Starting large three-phase motors or equipment causes voltage swells.
False
T/F A high test voltage from a hipot test will damage a device or cable in good working order.
False
T/F A high voltage ammeter is a test instrument specifically designed to identify the three phases of a three-phase distribution system as L1, L2, and L3.
False
T/F A momentary power interruption is a decrease to 0 V on one or more power lines lasting for more than 3 sec up to 1 min.
False
T/F A neutral conductor is a current-carrying conductor that is connected to loads through fuses, circuit breakers, and switches
False
T/F Attenuation is produced by absorption of light from splices, connectors, and other areas in the cable that cause problems.
False
T/F Cable height meters work by using radio frequency waves and do not have to come in contact with any cable.
False
When a product is designed to operate from a DC power source, ____ hipot testing is used. a. AC b. DC c. AC and DC d. none of the above
b. DC
On a __ , any leakage current flows through the ground (green) conductor back to ground during normal operation. The ground conductor prevents the exposed metal parts of the electrical device from becoming energized to the point of causing an electrical shock. a. ground fault circuit interrupter b. phase fault c. three-prong power cord device d. two-prong power cord device
c. three-prong power cord device
What are the biggest needs in modern communications? a. To be able to move Voice-Data-Video (VDV) communication to points along the network using all medium of wires. b. To maintain proper system operation, prevent communication and storage mistakes, and prevent file corruption. c. To move large amounts of data at faster speeds. d. To move large amounts of data at one time. e. All of the above
e. All of the above
What are the common causes of signal loss in fiber optic cable connectors? a. axial misalignment b. angular misalignment c. excessive separation between fibers d. rough fiber ends e. all of the above
e. all of the above
T/F Cable fault analyzers display information in numerical values, in words (PASS or FAIL), or with graphic displays
true
T/F The source of crosstalk is typically from another pair of wires in the same group or from another, adjacent group of wires.
true
T/F When using a cable fault analyzer, it is important to have the current manufacturer's reference points established.
true
T/F To prevent damage during an AC hipot test, some hipot testers actually apply AC voltage at a Very High Frequency (VHF).
False
_____ hipot testing typically indicates only a pass or fail of a product. When a product fails, the damage has already occurred. a. AC b. DC c. AC and DC d. none of the above
a. AC
Which of the following is not one of the most common causes of communication problems? a. Bandwidth b. Electromagnetic Interference (EMI) c. Exceeding minimum bend radius d. Improper cable installations e. Pulling too hard on the cable f. Radio Frequency Interference (RFI) g. Using staples
a. Bandwidth
____ is the frequency spectrum required or provied by communication networks. a. Bandwidth b. Frequency c. Megahertz d. Standing Wave Radio (SWR)
a. Bandwidth
___ problems are the number one cause of problems within a VDV system. a. Cable b. EMI c. RFI d. none of the above
a. Cable
Nonlinear loads are a common source of ___ problems. a. harmonic b. noise c. sags d. transients
a. harmonic
Fiber optic _____ allows the inspection (viewing) of a fiber end face to inspect for dirt, debris, or a fractured fiber. a. microscope b. Optical Loss Test Set (OLTS) c. Optical Time Domain Reflectometer (OTDR) d. Visual Fault Locator (VFL)
a. microscope
__tests are performed on newly designed components or on parts purchased from other companies that are being incorporated into the design of the product. a. Acceptance b. Design c. Nondestructive d. Production
b. Design
___is a term used to describe an electrical product designed so that a single ground fault cannot cause a dangerous electrical shock through any exposed parts of the products that can be touched by an electrician. a. Category II b. Double-insulated c. Single-insulated d. Two-prong
b. Double-insulated
What two basic measurements are taken to test insulation resistance?I. The actual leakage current flowing through the insulation. II. The actual leakage current flowing through the conductor .III. The actual resistance of the insulation. IV. The actual resistance of the conductor. a. I. and II. b. I. and III. c. II. and III. d. II. and IV.
b. I. and III.
___is/are the most common source of transient voltages on utility power distribution systems. a. Lighting dimmer controls b. Lightning c. Motors d. Variable frequency drives (VFDs)
b. Lightning
A _____verifies that a low resistance path exists between all exposed conductive metal parts and the ground conductor of the device. a. ground bond test b. ground continuity test c. ground fault test d. permanent ground test
b. ground continuity test
During a dielectric absorption test, insulation in good working order will show a continuous ____ in resistance. a. decrease b. increase
b. increase
A(n)____ test is a short-term test in which a megohmmeter is connected to a test conductor over about a 60 sec time period. a. dielectric absorption b. insulation spot c. insulation step voltage d. none of the above
b. insulation spot
The third harmonic on a 60 Hz power distribution line is ___ Hz. a. 20 b. 60 c. 180 d. 300
c. 180
____ is measured in dBm (decibels per milliwatt), with 0 dBm equal to 1 milliwatt. a. Cable length [Use as written] b. Continuity c. Optical power strength d. Power attenuation
c. Optical power strength
___are typically used to monitor for transient voltages. a. DMMs b. Oscilloscopes c. Power analyzer meters d. TDRs
c. Power analyzer meters
___ is the ratio of true power used in an AC circuit to apparent power delivered to the circuit. a. Harmonics b. Linear power c. Power factor d. Reactive power
c. Power factor
Light ___ is what limits the length of fiber cable, because it increases proportionally with cable length. a. absorption b. attenuation c. dispersion d. reflection
c. dispersion
A(n) _____ test is a test that creates electrical stress on internal insulation cracks to reveal aging or damage not found during other motor or conductor insulation tests. a. dielectric absorption b. insulation spot c. insulation step voltage d. none of the above
c. insulation step voltage
Communication cable is also commonly referred to as __cable. a. high voltage b. information c. low voltage d. transfer
c. low voltage
How are power lines balanced when they are more than 3% out of phase? a. After balancing the loads, re-test the phases for proper phase balance with a power analyzer meter. b. Take current measurements on all the single-phase power lines (use a clamp-on ammeter). c. When one or two power lines are overloaded, remove the load from the overloaded line and placethe load on a line that is not overloaded. d. All of the above
d. All of the above
Why is it preferable to acquire power quality measurements over time? a. Power quality problems are only detectable at certain times of the day. b. Power quality problems occur during a certain sequence of production operations. c. Power quality problems vary over time. d. All of the above
d. All of the above
A (n) ____ is obtained by dividing the values of a dielectric absorption test's 10-min measurement by the value of the test's 1-min measurement. a. dielectric absorption test b. insulation spot test c. insulation step voltage test d. polarization index
d. polarization index
Fiber optic cables are affected by ____ a. Electromagnetic Interference (EMI) b. Radio Frequency Interference (RFI) c. both of the above d. none of the above
d. none of the above
When voltage fluctuations are found to be more than ±8%, a(n) ___ must be added to the system. This is a device that provides precise voltage control to protect equipment from voltage sags (voltage dips) and voltage swells (voltage surges). a. capacitor b. inductor c. resistor d. voltage regulator (stabilizer)
d. voltage regulator (stabilizer)
A(n) ____ test is used to ensure that a cable is properly terminated to the correct terminals and that there are not any wires left unconnected or connected to the wrong terminal. a. attenuation b. NEXT c. resistance d. wire map
d. wire map
When energized parts of an electrical circuit are exposed, such as where conductors are terminated at fuse or circuit breaker panels, ____is used as the insulator. A. Dielectric B. Distance C. Plastic D. Rubber
B.Distance
T/F Acceptance tests are performed immediately after installation, but before the system is put into service.
True
T/F Advanced tests are needed on VDV circuits with acceptable voice transmission that are going to be used to transmit and receive other VDV signals because problems that might not be a factor with voice transmission can cause major problems during data transmission
True
T/F All VDV circuits must be tested and certified as meeting minimum industry standards prior to being placed in service.
True
T/F Anytime DC voltage is applied between a conductor and insulator, there will be an electrical charge held between the conductor and insulator (principle of capacitance)
True
T/F EMI and RFI problems can be reduced by using shielded cables and proper separation of VDV cables from power cables and other electrical loads that produce EMI.
True
T/F Harmonics cause motors to burn out, transformers to fail, circuit breakers to trip (nuisance tripping), and neutral conductors and other parts of the power distribution system to overheat
True
T/F Improper phase sequence (phase reversal) is the changing of the sequence of any two phases in a three-phase system or circuit. Improper phase sequence reverses motor rotation.
True
T/F The red light emitting from a VFL (visual fault locator) is visible at the fault
True
___ are used to indicate exactly when a voltage change took place and for what period of time. a. Recording meters b. Voltage testers c. Voltmeters with MIN MAX
a. Recording meters
The difference in temperature between an infrared meter reading and the ___ temperature reading is the amount of heat produced by the electrical component, circuit, or equipment being tested. a. ambient b. centigrade c. Fahrenheit d. Kelvin
a. ambient
Noncontact high voltage ___ are designed to be used as current clamps but have open ends (a U shape) to allow safer current measurements. a. ammeters b. piezo verifier c. verifiers d. voltmeters
a. ammeters
A tone generator is a test instrument that is used to place a tone on a cable that can be received by a(n) ____ at the other end of the cable. a. amplified probe b. Butt Set c. frequency counter d. TDR
a. amplified probe
A hipot test intentionally overstresses insulation by applying a much higher than normal voltage. When a weak or damaged point occurs in a circuit or cable, ____ will occur at the weak or damaged point. a. arcing b. inductance c. resistance d. welding of the cable
a. arcing
An Optical Time Domain Reflectometer (OTDR) is a test instrument that is used to measure fiber optic cable ____ . a. attenuation b. bandwidth c. frequency d. mode
a. attenuation
In ___cable, an outer braided conductor is used to shield an insulated inner conductor from outside electromagnetic interference (noise). a. coaxial b. fiber optic c. multi conductor d. twisted pair
a. coaxial
A(n) ____ high voltage meter is a voltmeter specifically designed to take measurements on high voltage cables. a. contact b. noncontact c. piezo d. none of the above
a. contact
A(n) ____ cable pair occurs when two common cable pairs are connected at the terminals of another. a. crossed b. open c. reversed d. shorted
a. crossed
How much variance in the length measurements between twisted pairs should be expected? a. Expect a 1% to 3% difference between twisted pairs. b. Expect a 2% to 5% difference between twisted pairs. c. Expect a 5% to 8% difference between twisted pairs. d. Expect a 5% to 10% difference between twisted pairs.
b. Expect a 2% to 5% difference between twisted pairs.
Poor power factor does not cause ___ a. a need to increase the sizes of conductors and equipment b. blown fuses c. heat damage to insulation and other circuit components d. reduction in the amount of useful power available
b. blown fuses
Phase unbalance causes three-phase motors to operate at temperatures ___and, therefore, the motor cannot deliver its rated horsepower. a. below ambient b. higher than nameplate ratings c. lower than nameplate ratings d. similar to full load current ratings
b. higher than nameplate ratings
When leakage current exceeds the specified limit, a(n) ___power cord must be used. a. long b. short c. three-prong d. two-prong
c. three-prong
To test for a motor that is single-phasing, both ___and___measurements must be taken, which are best performed while the motor is running. a. resistance / current b. resistance / temperature [Use as written] c. voltage / current d. voltage / temperature
c. voltage / current
Using the general rule of thumb, leakage current through insulation must not be greater than ___ mA for each 1000 V of operating voltage. a. 0.001 b. 0.01 c. 0.1 d. 1
d. 1
Why must cable heights be re-measured occasionally? a. Because cables sag over time b. Because of broken or damaged anchoring c. Because the height from the earth to the cable can change due to road resurfacing or landscaping d. All of the above
d. All of the above
Why might insulation resistance measurements taken with a standard ohmmeter not be accurate? a. High voltage must be used to obtain an accurate reading. b. Standard ohmmeters measure resistance by applying a low voltage. c. The resistance reading of good insulation might be millions, or tens of millions, of ohms out of the range of most standard ohmmeters. d. All of the above.
d. All of the above.
Which of the following is a linear load? a. Computer b. Copy machine c. Electric motor drive d. Incandescent lamp
d. Incandescent lamp
An electrical power system is a system that ____ and delivers electrical power to satisfactorily operate electrical loads designed for connection to a system. a. distributes b. produces c. transmits d. all of the above
d. all of the above
High voltage test probes should not be used to take measurements in high current applications such as ___ . a. broadcast transmitters b. high voltage power distribution systems c. induction-type heaters d. all of the above
d. all of the above
Temperature measurements identify problems or potential problems in electrical systems by identifying the heat produced by___ .a. switching gear b. transformers c. undersized conductors d. all of the above
d. all of the above
Typical tests include ensuring that the lines do not include any basic problems such as ___and insulation or water damage. a. incorrect wiring b. open circuits c. short-circuits d. all of the above
d. all of the above