Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
3E051 set D book 3
3E051 Set D book 3
| Question | Answer |
|---|---|
| Electrical cables are installed under roadways using | concrete-encased ducts |
| To ensure a sufficient number of spare ducts, you should allow for at least a 25% increase in the number of | cables |
| Why must ducts that terminate in a building be sealed? | To prevent gases and rodents from entering a building |
| What information is marked on manhole covers? | ownership or type of utility |
| What is the minimum size of a constructed manhole? | 4 feet by 6 feet by 6 feet |
| The use of 90 degree bends in duct lines is permitted for | pole risers |
| What is the purpose of a vault? | Isolate electrical equipment |
| What type of transformer is used in a vault? | subway transformer |
| Junction boxes located in an underground vault must | provide a water-tight seal |
| What specified percentage insulation level is used for medium-voltage ungrounded cables? | 133 % |
| The mechanical strength of underground cable is not a major concern because the cable is | not under tension |
| What material is used between the conductor and the cable insulation? | strand shielding |
| When pulling cable, the snatch block and pulling rope is attached to | the pulling-in iron in the manhole |
| Which is a determining factor in the spacing between manholes? | cable weight |
| Using the winch method, how many people does it take to pull underground cable safely? | 5 |
| What term describes an underground cable that is brought up through a conduit and attached to an overhead line? | riser |
| The device used to terminate high-voltage cables is called a | high-voltage termination |
| What is the purpose of a cable end seal? | prevents moisture from entering the cable |
| When making a load-break elbow, before attaching the crimp connector to the cable make sure you | align the hole on the end of the connector with the equipment bushing |
| What is the next step after sliding the elbow over the connector and cable? | Thread the electrode into the connector using the wrench from the elbow kit |
| What combustible gases are usually found in manholes? | natural gas or hydrocarbon fuels |
| What must you do when work takes place in a manhole that is 15 feet deep or more? | use a power blower for the entire work period |
| Which is not a manhole ventilation method? | funnel |
| How often must a gas test be made in a confined space? | continuously |
| What is the approximate bending radius for underground cable? | 5-12 times cable diameter |
| For racking purposes, how much straight cable need exist on each side of a cable splice? | 6 inches |
| What type of tape is used for fireproofing underground cable in manholes? | polymeric elastomer tape |
| What type of cable test is made after its installation but before it is placed into service? | acceptance test |
| When you perform maintenance on a cable, what is the acceptable test voltage? | 75% of acceptance test voltage |
| Power-factor tests can be performed at any voltage without exceeding the | line-to-ground rating of the cable |
| What is the easeiest and quickest way to find a cable fault? | visually |
| When you use the MM-1 fault locator or the thumper to locate a cable fault, what signal is produced when you are over the fault location? | fault locator signal fades out at the fault; thumper signal increases ot the loudest volume |
| In many cases, a cable fault is located at a | splice |
| Which cable splice kit requires the most labor to install? | conventional taped splice kit |
| What is the preferred method when making splices? | factory pre-form splice kit |
| What should be your first step when troubleshooting a pad mount transformer? | take a complete set of secondary phase-to-phase and phase-to-ground voltage readings |
| If tests indiciate an off-ratio winding, how would you verify whether the problem was in the transformer or not? | take secondary current readings on all three phases |
| Which airfield lights have yellow filters installed for the last 2,000 feet of runway? | runway end lights |
| Which airfield lights provide positive identification of the beginning of the operational runway surface for approaching aircraft? | Threshold lights |
| Which airfield lights are required on all lighted runways? | runway end lights |
| Which airfield fixture is unidirectional? | Approach |
| Which of the following items are found on ALSF-2 approaches? | 500 foot bar |
| What color is used for the taxiway edge light? | blue |
| At what minimum distance from the usable landing area does a station beacon also require an identification beacon? | 2 miles |
| One of the main control panels for the sirfield lights is in the vault; where is the other panel located? | control tower |
| Approximately how far should the airfield vault be from the runway? | 3,000 feet |
| What should you have available if you system uses 48-volt DC control? | an extra power supply module |
| How many conductors does the standard control cable for an airfield lighting control system contain? | 7 |
| Which airfield vault device is used to swap location of control of the airfield lights? | transfer switch |
| What airfield lighting control system device compensates for the voltage drop from the tower to vault? | low-burden pilot relay |
| What size cable is used for airfield light field circuits? | No. 8 |
| What type of transformer is used at each airfield light fixture to avoid the problems that are normally associated with series circuits? | isolating transformer |
| What is performed before installing a regulator? | pre-installation check |
| What size counterpoise is used for airfield lighting circuits? | No. 4 AWG |
| When replacing an IL transformer, what must the first listed amperage on the IL match? | the maximum amperage out put of the regulator |
| What feature is common to elevated airfield lights? | They are built with frangible construction |
| What is the primary purpose of the rotating/airport beacon? | to guide the pilot to the airfield |
| How many revolutions per minute does the airport beacon turn? | 6 |
| What occurs when the operating lamp in the airport beacon fails? | a reserve lamp is placed in operation automatically |
| What voltage is neccessary to run the airport beacon? | 120/240 volts |
| What is the minimum number of hazard beacons used on one side of an extensive or extremely high antenna? | 3 |
| What device can be used to change voltage up or down for the airport beacon lamps? | the tap changer in the distribution transformer |
| How often must you check the level of the airport beacon base and the beacon motor's gears? | annually |
| How often does each stobe light unit flash? | twice each second |
| How many brightness steps is the strobe system capable of producing? | 3 |
| What voltage rating is the wire that connects the flash head to the individual control cabinet? | 3 kV |
| When does the hour (elapsed-time) meter operate? | when system is operated on high intensity |
| Which items still have power when CB1 in the MCC is turned off? | The GFCI outlet and maintenance lamp |
| How do you bypass the interlock switch on the Individual Control Cabinet? | pull on the plunger |
| How long does it take the flash capacitors to bleed off their charge? | one minute |
| What is indicated when two skips occur within 100 flashes of the condenser discharge system? | a worn out lamp |
| Where should you start troubleshooting if you turn the strobe system on and it does nothing? | the source of power |
| Which of the following is highest priority when troubleshooting the condenser discharge system? | getting the lights to flash in sequence |
| to check the coil of a deenergized relay, use a? | ohmmeter |
| How are animals prevented from chewing on airfield lighting fixture cords? | fixtures are designed so that no cords are exposed |
| What is used to maintain contact with the tower when away from the truck? | hand-held radios |
| Which approach lighting system maintenance item must be performed daily? | check and record burned out lamps |
| When should you check all approach light fixtures for alignment? | semiannually |
| Where is the PAPI system located? | on the left side of the runway |
| What calculation is used to determine the load on an airfield regulator? | input current times inpout voltage times the regulator power factor |
| How often are dielectric oil tests made on airfield regulators? | annually |
| When you tie together two airfield light circuits for emergency operation, what do you do to prevent regulator overload? | move the control wire from step 5 relay to step 4 relay |
| In order to preform a DC hi-potential test on an airfield light circuit, what do you do with the leads once you remove them from the airfield regulator? | aupport both leads and keep them clear of each other and the ground |
| When using radios, which two words should you use to describe circuit conditions? | open/closed |
| If a combination of faults exits in an airfield circuit, which faults do you clear first? | grounds |
| Ballast voltages in multiple street light circuits usually are | 120 to 480 volts |
| What type of light fixture should be placed near hidden entrances? | security light |
| In an incandescent lamp, how much consumed energy is lost in the form of heat? | 90% |
| Which olighting system should be considered for retorofit with a more efficient system? | mercury vapor |
| What letter represents the American National Standards Institute's special designation code for high-pressure sodium lamps? | S |
| Photocells are used extensively in which type of lighting system? | Street lighting |
| To ensure that the proper anount of light is provided after fixture installation, check the lighting with a | light meter |
| High-pressure sodium lamp cycling usually indicates | the end of normal lamp life |
| When troubleshooting a 120-volt photocell, which conductor should provide power to the light fixture? | load (red) |
| What lighting system practice results in reduced maintenance costs and increased safety? | group relamping |
Created by:
melissafish
Popular Military sets