Study Guide Electrical
Answer for # 4
A. 0 volts
Electric trailer brakes are designed to operate on _______. A. 12VDC B. 24VDC C. 120VAC D. 6VDC
A. 12VDC
A clearance lamp circuit has a 15 amp fuse installed, what is the maximum draw that should be applied to that circuit? A. 15 amps B. 12 amps C. 18 amps D. 10 amps
A. 15 amps
A single electromagnet for 7" to 12" trailer brake assemblies should have approximately ______ resistance. A. 3-4 ohms B. 12 ohms C. 6-8 ohms D. .03-.04 ohms
A. 3 to 4 ohms
A solar panel is being wired to an RV charging system. RV Technician A says the panel should be wired directly to the storage batteries. RV Technician B says that a circuit breaker should be installed between the storage batteries and the inverter. A. A only B. B only C. Both A and B D. Neither A nor B
A. A only
RV Technician A says that a converter outputs 12 VDC from 120 VAC input. RV Technician B says that an inverter does the same thing. Who is correct? A. A only B. B only C. Both A and B D. Neither A nor B
A. A only
RV Technician A says that one purpose of a Hi-Pot test is to find out if the shore power connection to the RV is wired correctly. RV Technician B says one purpose of a Hi-Pot test is to determine if there are any problems in the RV's DC wiring. Who is correct? A. A only B. B only C. Both A and B D. Neither A nor B
A. A only
Answer for #7
A. A to B
The rotor becomes an electromagnet when ______. A. DC voltage is supplied through the brush block, slip ring and into the windings B. AC voltage is supplied through the brush block, slip ring and into the winding C. the north and south poles meet D. when load is applied
A. DC voltage is supplied through the brush block, slip ring and into the windings
What procedure must be used when passing all conductors through bulkheads and/or partitions? A. Employ clamp & grommets to prevent chaffing. B. Wire tie all parallel wires. C. Add heat retardant material. D. Separate dissimilar wires colors.
A. Employ clamp & grommets to prevent chaffing.
Which of these is a good reason for disconnecting the negative battery cable connection first? A. In case the wrench touches a metal part of the vehicle. B. In case the battery positive cable connection is too tight to get loose. C. In case the battery positive cable connection is sulfated. D. In case the battery positive cable connection cannot be easily accessed.
A. In case the wrench touches a metal part of the vehicle.
Increasing the generator output load would have what effect on the rotor field voltage? A. Increase voltage B. Decrease voltage C. No change to voltage D. Reverse polarity of voltage
A. Increase voltage
Which of these best describes what an energy management system does? A. It automatically removes loads to prevent overloading the generator or shore power. B. It monitors the AC load and manages the output from the generator. C. It protects the vehicle battery from being discharged when the vehicle is not running. D. It protects the RV system if the shore power plug is incorrectly polarized.
A. It automatically removes loads to prevent overloading the generator or shore power.
With the generator running and AC output yielding low frequency, what is a probable cause? A. Low engine speed B. Low exciter voltage C. High exciter voltage D. Defective output circuit breaker
A. Low engine speed
Which of these component(s) in a generator determines the output as load on the generator is increased or decreased? A. The rotor field windings. B. The stator battery charge winding. C. The stator power windings. D. The initialization windings.
A. The rotor field windings.
Which of these might cause a fault (burned wiring) at the transfer switch of an RV after it is connected to 50 amp shore power? A. The shore power receptacle has reversed wiring. B. The transfer switch contacts are faulty. C. An open circuit in an appliance has caused the transfer switch to fail. D. The neutral is insulated from ground in the shore power connector.
A. The shore power receptacle has reversed wiring.
If a 50 amp (split phase) RV cable connector is adapted for use with a 30 amp RV shore power receptacle, what happens to the potential (voltage) across the two 50 amp legs at the RV breaker panel? A. There is no voltage across the legs because they are in phase with each other. B. There is 220 volts across the 2 legs because they are out of phase with each other. C. Only one of the 2 legs will have power; the other will have no power. D. There is no voltage on either leg because 50 amp service cannot be connected to a 30 amp shore power connector.
A. There is no voltage across the legs because they are in phase with each other.
What is the purpose of DC exciter voltage supplied to a generator? A. To "jump start" the field windings upon engine startup. B. To enable the stator windings to become energized. C. To control the generator's RPM D. To control the generator's output frequency.
A. To "jump start" the field windings upon engine startup.
Which of these is the best reason for exercising the generator in an RV? A. To keep fresh fuel in the fuel system. B. To prevent sludge buildup in the engine cooling system. C. To keep the generator's engine shrouding free of debris. D. To prevent the carburetor linkage from becoming fouled.
A. To keep fresh fuel in the fuel system.
Current supplied by commercial power lines and RV generators is known as ______. A. alternating current B. direct current C. inducted current D. accelerating current
A. alternating current
When stripping a wire, you should strip only ________. A. an area to fit in the connector B. 1/8" larger than the connector C. 1/4" larger than the connector D. 3/8" larger than the connector
A. an area to fit in the connector
To bench test a start solenoid, connect an ohmmeter to the two large terminals and apply 12-volts DC to the two smaller terminals. On the meter, a good solenoid will indicate ________. A. continuity B. infinity C. about 800-ohms D. 12-volts at the two large terminals
A. continuity
As the gauge of copper wire increases, its diameter _______. A. decreases in size B. changes composition C. increases in size D. varies in length
A. decreases in size
The speed/frequency differential between no-load and full-load conditions is known as _______. A. droop B. sag C. apex D. null
A. droop
The neutral wire connected to the 120V AC shoreline power should be ungrounded A. in all 120V AC RV wiring B. only in RV's employing 3 or more branch circuits C. only when 30 amp service is used D. only in "Class A: motor homes
A. in all 120V AC RV wiring
Connecting batteries in series will ________. A. increases voltage B. increases current C. increases amp-hour capacity D. cause immediate failure
A. increases voltage
Proper connection of the white wire and the bare copper wire in a 120 VAC distribution panelboard is _______. A. isolated from each other B. wire together C. must be connected to ground rod D. never used
A. isolated from each other
A diode should have continuity in ______. A. one direction B. two directions C. three directions D. four directions
A. one direction
Wet location covers are required on all AC receptacles located ______. A. outside B. in the bathroom C. in the kitchen D. bedroom
A. outside
If a customer complains of receiving shocks from his/her vehicle when plugged in, the first test should be a ________. A. polarity check of the shore cord B. polarity check of the battery system C. voltage check D. converter voltage check
A. polarity check of the shore cord
A pulse preventer is a ______. A. relay B. capacitor C. diode D. switch
A. relay
Bonding clamps are designed and installed to ________. A. safely conduct current likely to be imposed between two metal parts B. act as a fuseable link when installing electrical components C. create a common connection on the load wire of two or more components D. alternate route for load distribution
A. safely conduct current likely to be imposed between two metal parts
Which component is NOT a part of a typical electrical trailer drum brake assembly? A. slave cylinder B. magnet assembly C. adjuster screw assembly D. brake shoes
A. slave cylinder
The electro-mechanical switching device used to connect the battery voltage to the generator starter is called the _____. A. starter relay B. ignition coil C. condenser coil D. magneto
A. starter relay
Checking the electromagnet for proper wear will involve the use of a _________. A. straight edge B. VOM meter C. rasp D. sight gauge
A. straight edge
A capacitor is a device that _______. A. temporarily stores electrical energy B. is used to check electrical pressure C. indicates direction of a magnetic field D. measures electrostatic force between charged particles
A. temporarily stores electrical energy
Any of these could cause a starter motor to crank slowly EXCEPT for A. too large battery cables B. corroded battery connections C. corroded starter ground D. low battery voltage
A. too large battery cables
A conductor is used to _________. A. transfer electricity from one point to another B. resists electrical current C. allow current to leak to ground D. induces electricity to other wires
A. transfer electricity from one point to another
A 10-3 non-metallic sheathed cable consists of __________. A. two hots (black and red), one neutral (white), and one ground (bare or green) B. two hots (black and blue), one neutral (white), and one ground (green) C. two hots (black and white), one neutral (white), and one ground (green) D. two hots (black and red), one neutral (white), and one ground (brown)
A. two hots (black and red), one neutral (white), and one ground (bare or green)
All of these statements about conducting a high-potential ("hot-pot") leakage test on an RV are true EXCEPT A. voltage is applied across the Black and the White wires B. voltage is applied across the Neutral and White wire C. voltage is applied across the Neutral and the Black wire D. the Black and White wires may be connected together for the test
A. voltage is applied across the Black and the White wires
The Specific Gravity of a fully charged lead acid battery is? A. 1.285 B. 1.265 C. 1.225 D. 1.155
B. 1.265
What minimum gauge wire should be used for a 30 amp circuit? A. 8 B. 10 C. 12 D. 14
B. 10
Answer to #83
B. 12 volts DC
A mobile RV air conditioning system is being installed. Which of these kinds of wiring would typically be used? A. 14/2 Romex cable B. 12/2 NM type cable C. 12/2 AWG in conduit D. 10/3 in BX sheathing
B. 12/2 NM type cable
Black (Hot), White (Neutral) and Ground provide ______volts. A. 12 B. 120 C. 240 D. 480
B. 120
When you connect four 6V, 200-amp DC batteries in series you will get ______. A. 6 VDC, l200 amps B. 24 VDC, 200 amps C. 6 VDC, 800 amps D. 24 VDC, 800 amps
B. 24 VDC, 200 amps
Answer to #17
B. 24 volts DC
A 60 Hz generator designed to rotate at 1800 RPM will have a A. 2-pole rotor B. 4-pole rotor C. 2-pole stator D. 4-pole stator
B. 4-pole rotor
Power in one of the 120 volt AC circuits in an RV is found to be intermittent. Which of these could be the cause? A. A defective shore power connection. B. A faulty connection at the breaker panel. C. A faulty generator. D. A faulty inverter.y
B. A faulty connection at the breaker panel.
Which of these could cause a failure of external 120 volt AC (shore power) to provide electricity to an RV? A. A faulty generator B. A faulty transfer switch C. A faulty GFCI D. A faulty battery isolator
B. A faulty transfer switch
The breakaway switch must be mounted in _________. A. the tow vehicle engine compartment B. a swivel configuration C. a protective compartment D. compliance to the national transportation safety code
B. A swivel configuration
Answer to #9
B. B only
RV Technician A says that a starting battery is useful for supplying power for prolonged energy-draining periods. RV Technician B says that a deep-cycle battery can best be used as a cranking motor battery. Who is correct? A. A only B. B only C. Both A and B D. Neither A nor B
B. B only
Solar panels are being installed on the roof of a recreational coach. Technician A says that the panels should be installed at an angle so that they can directly face the sun. Technician B says that it's important to leave a 1 inch space between the panels and the roof. Who is correct? A. A only B. B only C. Both A and B D. Neither A nor B
B. B only
A 7-pin towing connector is being wired to a trailer with electric brakes. Which color of wire should be used for the brake circuit? A. Yellow B. Blue C. White D. Black
B. Blue
Which of these is a correct statement regarding the use of a multimeter? A. Connect a voltmeter in a series in a circuit. B. Connect an ammeter in series in a circuit. C. Connect an ammeter in parallel in a circuit. D. Connect an ohmmeter in a live circuit.
B. Connect an ammeter in series in a circuit.
What should be performed when a bonding strap or bonding screw is present in a distribution panelboard intended for use in an RV? A. Attach strap or screw to panel. B. Discard strap or screw. C. Add electrical clamp harness. D. Attach strap or screw to ground.
B. Discard strap or screw.
An RV generator is being service. What should the RV Technician do to prevent the generator from automatically starting? A. Disconnect the generator battery positive cable. B. Disconnect the generator battery negative cable. C. Disconnect the vehicle cranking battery. D. Disconnect the spark plug HV lead.
B. Disconnect the generator battery negative cable.
What could happen if the 120 volt AC neutral and ground wires were bonded at the RV's breaker panel? A. There is no problem because the panel is correctly wired. B. If a receptacle in the RV is wired backwards, the coach skin could become "hot". C. Some appliances would not work correctly. D. All of the circuit breakers would trip.
B. If a receptacle in the RV is wired backwards, the coach skin could become "hot".
Answer to #132
B. SC
An RV Technician is using an ohmmeter to check the windings of a generator's fields and finds that their resistance is below specifications. Which of these is the most likely cause? A. Defective slip rings B. Shorted rotor windings C. Defective brushes D. Shorted stator windings
B. Shorted rotor windings
An air-cooled generator in an RV experiences overheating. Which of these is the most likely cause? A. The fuel mixture is too rich. B. The cooling shroud is blocked with debris. C. The governor adjustment is set incorrectly. D. The wrong type of gasoline is being used.
B. The cooling shroud is blocked with debris.
A brake controller actuator is being installed in an SUV. What is the best way to determine the proper fuse size to be used? A. Use a fuse one size smaller than the kind normally approved for the trailer. B. Use a fuse size equal to 3 amps per brake magnet used in the brake system. C. Use a fuse that is rated for 5 amps per brake magnet used in the brake system. D. Use a fuse that is recommended by the owner of the trailer.
B. Use a fuse size equal to 3 amps per brake magnet used in the brake system.
Before removing and installing a replacement power converter you would ______. A. turn the branch AC circuit breaker on B. always disconnect battery and AC power supply C. always disconnect battery isolator D. always short across battery terminal (+) to ground to discharge convertor filter.
B. always disconnect battery and AC power supply
The device that automatically allows only one source of 120 VAC power to be used by the RV at any time is called a/an A. safety relief valve B. automatic transfer switch C. circuit breaker D. automatic demand regulator
B. automatic transfer switch
When installing a fuel tank on a towable unit the fuel tank should be installed _______ of the generator. A. above the level B. below the level C. at the same level D. it does not matter
B. below the level
If the speed of an unregulated alternator is doubled, the output/voltage will ______. A. remain the same B. double C. quadruple D. decrease
B. double
A ______ is the only type of converter that must have a battery attached for proper operation. A. switchmode B. ferro-resonant C. linear D. exponential
B. ferro-resonant
To safely remove a battery from a vehicle, the negative lead should be removed _______> A. last B. first C. first, only if convenient D. doesn't make a difference
B. first
The amount of amperage that can be carried by a 10 gauge wire versus a 16 gauge wire is ________. A. lower B. higher C. equal D. not measurable
B. higher
A possible cause of a hunting or surging AC generator would be a/an _______. A. rich fuel mixture B. incorrect governor adjustment C. restricted exhaust system D. incorrect ignition timing
B. incorrect governor adjustment
1000 feet of 14 gauge wire whose temperature is 70 degrees F has a resistance that is __________ 1000 feet of 10 gauge wire at the same temperature. A. equal to B. larger than C. less than D. no difference
B. larger than
What type of battery is used in an RV's 12v system? A. alkaline B. lead acid C. nickel cadmium D. dry cell
B. lead acid
The battery disconnect system in a vehicle is primarily used to ______. A. change the batteries B. prevent premature battery discharge C. balance the voltage between batteries D. be a constant source of AC voltage
B. prevent premature battery discharge
An RV "hot skin" condition is most likely caused by A. excessive shore power voltage B. reversed polarity at the shore power plug C. a defective GFCI in the circuit D. an open neutral connection
B. reversed polarity at the shore power plug
The field strength (magnetism) in a generator can be increased by A. increasing the AC power going to the stator B. supplying more DC voltage to the rotor C. increasing the RPM of the generator D. decreasing the load on the generator.
B. supplying more DC voltage to the rotor
The AC single-phase frequency output of a generator is determined by all of these EXCEPT A. the speed of the engine B. the type of fuel used C. the generator governor setting D. the number of rotor windings
B. the type of fuel used
12-volt DC blower motors are ________protected. A. split B. thermally C. moisture D. AC
B. thermally
When splicing a 120 VAC wire you must A. use listed electrical tape B. use a junction box C. use both listed electrical tape and a junction box D. 120 VAC wire is not spliced
B. use a junction box
On a linear converter, the output is _______. A. filtered and variable B. variable and unfiltered C. filtered and constant D. unfiltered and constant
B. variable and unfiltered
This electronic device, found on newer RV generators, is not repairable and applies battery voltage to the rotor. It also monitors the output voltage of the stator. A. ignition magneto B. voltage regulator C. commutator D. electronic variable speed governor
B. voltage regulator
The type of power produced by the oldest type of RV converter is ________. A. 12 Volt AC B. 12 Volt pure DC C. 12 Volt Unfiltered DC D. 12 Volt Square Wave
C. 12 Volt Unfiltered DC
A fully charged battery at rest will show an approximate voltage of _____ DC volts. A. 14.5 B. 14.1 C. 12.8 D. 12.0
C. 12.8
An inverter is used to change ________. A. 120V AC to 12V DC B. 12V DC to 24V DC C. 12V DC to 120V AC D. 120V AC to 24V DC
C. 12V DC to 120V AC
How much amperage can be safely handled by 14 gauge NM cable? A. 10 amps B. 12 amps C. 15 amps D. 20 amps
C. 15 amps
Two 12V batteries connected in series provide ______ VDC. A. 6 B. 12 C. 24 D. 48
C. 24
When you connect four 6V, 200-amp DC batteries in parallel you will get _______. A. 6 VDC, 200 amps B. 24 VD , 200 amps C. 6 VDC, 800 amps D. 24 VDC, 800 amps
C. 6 VDC, 800 amps
Answer to #151
C. 7 - 10 kW
The specific gravity of a wet-cell battery reads 11.25. This means that the battery is _______ charged. A. 25% B. 50% C. 75 % D. 100%
C. 75%
Which of these could cause a ground fault interrupter (GFCI) to trip? A. A leakage of 4 to 6 millivolts B. A leakage of 6 to 10 ohms C. A leakage of 4 to 6 milliamps D. A leakage of 6 to 10 milliwatts
C. A leakage of 4 to 6 milliamps
What occurs when two adjacent conductors make electrical contact and bypass a portion of a circuit? A. A ground B. An open C. A short D. The circuit resistance increases
C. A short
If a GFCI receptacle is properly wired, what condition exists? A. Polarity test are not necessary. B. Involved circuit must have circuit breaker protection. C. All receptacles downstream will be GFCI protected. D. Vehicle grounding for interior lights is not required.
C. All receptacles downstream will be GFCI protected
A low oil pressure switch for a generator has been removed from the engine and is being checked for continuity. Which of these could the RV Technician use to test it? A. A non-self powered test light. B. A digital voltmeter. C. An ohmmeter. D. A noid light.
C. An ohmmeter.
Answer to #134
C. BCR
RV Technician A says electricity is produced when a magnet is moved through a winding, RV Technician B says that magnetism is produced when electricity is applied to a coil. Who is correct? A. A only B. B only C. Both A and B D. Neither A nor B
C. Both A and B
Technician A says that a fully charged lead-acid battery should read no less than 12.65 volts DC. Technician B says that a fully charged gel-cell battery should read no less than 13.0 volts DC. Who is correct? A. A only B. B only C. Both A and B D. Neither A nor B
C. Both A and B are correct
A customer complains of always finding oil-fouled spark plugs. Which of the following symptoms will not cause oil-fouled plugs? A. Low engine compression B. Faulty or soiled crankcase breather C. Dirty air filter element D. Worn piston rings and/or valve guides
C. Dirty air filter element
Which of these would cause an AGS to activate? A. Select startup from a hand-held remote B. Select startup from a remote panel C. Have a low coach battery SOC D. Have a low vehicle battery SOC
C. Have a low coach battery SOC
Which of these is the best type of non-conductive fuel line to be used between the fuel supply and a generator installed in an RV? A. Reinforced polyurethane tubing B. Rubber braided tubing C. Neoprene tubing D. Braided steel rubber tubing
C. Neoprene tubing
Which of these types of cables is best used for applications which are subjected to vibration? A. Coaxial cable B. Solid core copper cable C. Stranded copper cable D. Aluminum stranded cable
C. Stranded copper cable
After an RV Technician connects an ammeter into a live AC circuit, the internal ammeter fuse blows. Which of these is the most likely cause? A. The circuit voltage is too high. B. The ammeter is set to DC. C. The ammeter was connected in parallel with a load. D. The ammeter was connected in series with a load.
C. The ammeter was connected in parallel with a load.
Answer to # 32
C. The coach battery should be connected to terminal A
Any of these methods may be commonly used to cause a generator to crank and start EXCEPT A. a remote panel B. AGS C. a hand crank D. a wireless remote
C. a hand crank
The function of an auto transfer switch ______. A. connects all pwer sources together B. only used with battery chargers C. allows only one power source to the vehicle's circuit at a time D. moves the vehicle electrical control from front dash area to entertainment center
C. allows only one power source to the vehicle's circuit at a time
To determine correct wire size, you must calculate the ______load. A. switch B. hardness C. amperage D. voltage
C. amperage
A cranking battery in good condition has an open-circuit reading of 12.6 VDC. When the starter is engaged, voltage at the starter solenoid's B+ terminal to ground should be no less than A. approximately 12.0 volts B. approximately 12.2 volts C. approximately 12.4 volts D. approximately 12.6 volts
C. approximately 12.4 volts
Chemically produced electricity is commonly produced from _______. A. 110 outlets B. generators C. batteries D. gasolinet
C. batteries
Paralleling batteries increases ______. A. voltage B. resistance C. capacity D. inductance
C. capacity
In order for a hot skin test to be accurate, all of these must be done EXCEPT A. the RV must be plugged into a live source of shore power. B. the RV panel breakers should be turned on the ON position. C. check for voltage between an RV receptacle's hot cavity and a bare RV ground. D. check for potential between an RV bare metal surface and a good earth ground.
C. check for voltage between an RV receptacle's hot cavity and a bare RV ground.
When making a 120V AC connection to a screw, the wire should be circled around the screw post connection in a _______direction. A. counter clockwise B. left hand C. clockwise D. opposite
C. clockwise
To clean a spark arrester, remove the clean-out plug from the muffler and run the generator ________. A. until white smoke emits from the exhause B. under a heavy load for one hour C. for 15 to 20 minutes D. Never clean the spark arrester; always replace it.
C. for 15 to 20 minutes
All of these statements about GFCI circuits are true EXCEPT A. a GFCI can protect outlets wired downstream of the GFCI B. if a fault occurs downstream from the GFCI, all downstream outlets are affected C. if the GFCI trips, downstream outlets will not be affected D. if the GFCI is wired incorrectly, all downstream outlets are affected
C. if the GFCI trips, downstream outlets will not be affected
If voltage output is below nominal, the voltage regulator will ______. A. shutoff B. trip the circuit breaker C. increase DC voltage to the rotor D. decrease DC voltage to the rotor
C. increase DC voltage to the rotor
Connecting batteries in parallel will ______. A. increases voltage B. increase current C. increases amp-hour capacity D. cause immediate failure
C. increases amp-hour capacity
On diesel engines the governor controls the _________. A. regulator B. carburetor C. injector pump D. fuel pump
C. injector pump
The batteries used in RV applications are__________. A. lead carbon B. steel carbon C. lead acid D. steel acid
C. lead acid
Ideally, an RV generator should be exercised every: A. day B. week C. month D. year
C. month
When testing a good diode with an ohmmeter and then measuring this part again with the leads reversed, you should have A. two low readings. B. two high (infinite) reading.s C. one high (infinite) and one low reading. D. This is an incorrect test.
C. one high (infinite) and one low reading.
Another name used to describe an inertia-type brake control system is A. time based system B. swinging pendulum system C. proportional system D. actuator type system
C. proportional system
The number and size of solar panels required to be installed on the roof of an RV is determined by all of these factors EXCEPT A. the total number of storage batteries B. the ampere-hour rating of each storage battery C. the brand (manufacturer) of the storage batteries D. the electrical load on the storage batteries
C. the brand (manufacturer) of the storage batteries
When replacing fuses on any appliance, you should always use one with ______. A. a higher amp and volt rating B. a lower amp rating C. the same amp and volt rating D. the same amp and higher volt rating
C. the same amp and volt rating
When an RV manufacturer installs an inverter in an RV, the purpose of the inverter is to A. provide 12 VDC vehicle battery power to the coach B. protect the vehicle battery from being discharged by electrical loads in the coach C. transform 12 VDC coach battery power to 120 VAC for coach electrical loads D. convert 120 VAC power to 12 VDC power for loads in the coach
C. transform 12 VDC coach battery power to 120 VAC for coach electrical loads
50 amp service provides __________. A. one 120 volt line at 50 amps B. one 240 volt line at 50 amps C. two lines of 120 volts at 50 amps each D. two lines of 240 volts at 50 amps each
C. two lines of 120 volts at 50 amps each
The linear converter has ________ output. A. filtered and variable B. variable and isolated C. variable and unfiltered D. isolated and unfiltered
C. variable and unfiltered
Answer for #2
D. 12 volts
How much voltage would a voltmeter read if its leads are inserted into the "hot" cavities of two live 120 volt receptacles which are on opposite legs of a breaker panel? A. 0 volts B. 120 VDC C. 0 VAC D. 240 VAC
D. 240 VAC
An RV Technician is using a voltmeter to check for power in a live 50 amp distribution panel. What voltage reading would be seen if the voltmeter leads were placed across both legs? A. 0 volts DC B. 120 volts AC C. 240 volts DC D. 240 volts AC
D. 240 volts AC
Answer to #11
D. 300 watts
When a generator is equipped with a manual carburetor preheater, the lever should be moved to the winter position when the temperature is below _______________. A. 32°F (0°C) B. 40°F (4°C) C. 45°F (7°C) D. 50°F (10°C)
D. 50°F (10°C)
An absorbed glass mat (AGM) battery has experienced plate sulfation and slightly differing cell voltages. Which of these procedures could be used to correct the problem? A. Fast charge the battery at 13.4 volts for 30 minutes. B. Fast charge the battery at 14.4 volts for 30 minutes. C. Condition the battery at 15.0 volts for 1 hour. D. Equalize the battery at 15.5 volts for 3 hours.
D. Equalize the battery at 15.5 volts for 3 hours
Answer to #13
D. Go up
Answer to # 136
D. ISD
Due to a generator malfunction, voltage being fed into a resistive load is raised from its nominal 120 volts AC to 140 VAC. What happens to the amperage? A. It is rejected by the load device B. It goes down C. It stays the same D. It goes up
D. It goes up
Answer to #15
D. It goes up, then to zero
An RV comes equipped with a 3-prong shore power connector. Which of these options best describes how to connect a 240 volt appliance for use in the RV? A. Upgrade the shore power cord with a 4-prong shore power plug. B. Use a 3-prong to 4-prong adaptor and plug into a 50 amp shore power pedestal. C. Use a 2:1 transformer to step the appliance down to 120 volts. D. It should not be connected because a 240 volt appliance should not be used in this RV.
D. It should not be connected because a 240 volt appliance should not be used in this RV.
A generator experiences low output frequency. Which of these could be the cause? A. Worn slip rings B. Low exciter current C. Worn brushes D. Low engine RPM
D. Low engine RPM
An on-line gasoline fueled RV generator stumbles and quits running. Which of these is the most likely cause? A. A dead coach battery B. Low fuel level in the vehicle fuel tank C. An electrical overload D. Low fuel level in the coach fuel tank
D. Low fuel level in the coach fuel tank
The primary in a 120 volt AC transformer experiences a short across several of its windings. What is the effect on the circuit? A. Voltage goes up. B. Amperage goes down. C. Watts go down. D. Resistance goes down.
D. Resistance goes down.
A water pump runs continuously with the control relay de-energized. Which of the following is the most likely cause? A. An open wire to the pump. B. A shorted pump. C. The switch remains open. D. The switch remains closed.
D. The switch remains closed.
When installing a new 120 VAC receptacle when is a GFCI not required? A. In bathroom B. Six feet from wet location C. Exterior of RV D. Two feet from a battery location
D. Two feet from a battery location
A brake controller is being installed in a pickup truck for towing an RV .Which of these is the best option for connecting to the truck's electrical circuit? A. Use 14 gauge solid copper wire with a fast-blow fuse. B. Use 12 gauge stranded copper wire with a slow-blow fuse. C. Use 10 gauge stranded wire with a 25 amp fuse. D. Use 12 gauge stranded wire with a 20 amp self-resetting circuit breaker.
D. Use 12 gauge stranded wire with a 20 amp self-resetting circuit breaker.
Whenever a tow vehicle's engine is running, a whining noise corresponding to engine RPM is heard in radio. Any of these could be the cause EXCEPT A. a poor ground connection at the radio B. a faulty filter capacitor in the charging system C. poor shielding of the radio antenna D. a faulty charging system voltage regulator
D. a faulty charging system voltage regulator
When a load is placed on a generator with automatic generator start (AGS) system, the generator fails to crank and start up. Any of these could be the cause EXCEPT A. a faulty starter solenoid B. an improperly set DIP swithc C. a faulty low oil pressure (LOP) switch D. a faulty vehicle cranking battery
D. a faulty vehicle cranking battery
Resistance in a circuit will increase under any of these conditions EXCEPT for A. increased wire length B. smaller wire diameter C. hot wiring D. a larger fuse
D. a larger fuse
A generator bogs down when a heavy load is placed on it, yet the generator's load (wattage) rating has not been exceeded. The RV technician should first check for A. low engine compression B. burned valves C. a plugged exhaust system D. a plugged spark arrestor
D. a plugged spark arrestor
A generator engine is emitting black smoke from its exhaust. This is an indication of A. worn piston rings B. burned valves C. a leaking head gasket D. a rich fuel mixture
D. a rich fuel mixture
The marker lights on an RV trailer are found to be glowing dimly as compared to those on the tow vehicle. Any of these could be the cause EXCEPT A. a chaffed wore in the trailer wiring harness. B. a poor ground connection on the trailer. C. corrosion in the trailer hitch electrical connector. D. an open in the trailer wiring harness
D. an open in the trailer wiring harness
Which type of battery is most often used for the chassis battery? A. lead acid gelled B. deep-cycle C. nickel cadmium D. automotive
D. automotive
A 0 - 90 ohm propane sending unit circuit is being diagnosed and found to have an open circuit. With this kind of fault, the receiver reads ________. A. empty B. one half full C. full D. beyond full
D. beyond full
A gassing battery gives off __________. A. sulfur oxide B. oxygen C. nitrogen D. hydrogen
D. hydrogen
To check a rotor for defective windings, an RV technician should use a(n) A. growler B. voltmeter C. ammeter D. ohmmeter
D. ohmmeter
The electrolyte in the wet-cell lead acid battery consists of A. phosphoric acid and seltzer water B. hydrochloric acid and bottled water C. muriatic acid and tap water D. sulfuric acid and distilled water
D. sulfuric acid and distilled water
A 5th wheel trailer electric brake system experiences grabbing brakes. Any of these descriptions could be the cause EXCEPT A. the threshold adjustment is set incorrectly B. the level adjustment is set incorrectly C. the brake sensor adjusting wheel threshold is set incorrectly D. the pendulum is stuck and prevented from working correctly
D. the pendulum is stuck and prevented from working correctly
If an RV has a hot skin condition when plugged into shore power, the RV Technician can detect it by A. using a volt meter to measure from hot to neutral in one of the RV's receptacles. B. using an ohmmeter to measure from neutral to a good ground. C. using an ammeter to measure from hot and neutral in one of the RV's receptacles. D. using a voltmeter to measure from an RV bare metal surface to a good earth ground.
D. using a voltmeter to measure from an RV bare metal surface to a good earth ground.
When the field current supplied to the generator's rotor is increased, generator output A. will stabilize B. will go down C. fluctuate D. will go up
D. will go up