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100 Cards in this Set
- Front
- Back
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What were installed in the elevator to operate the elevator after magnetic switches became available? |
Push buttons |
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What was the biggest problem with AC elevator controls? |
Floor accuracy |
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What are the new control systems that are being installed on old AC elevators to improve ride and floor accuracy called? |
VVVF |
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What varied armature resistance in early DC elevators? |
Rheostat control |
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A 3-phase, full-wave rectifier uses how many rectifier diodes |
6 |
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What will happen to the DC voltage if the AC fuse of a 3-phase, full-wave rectifier blows |
The DC voltage will decrease |
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What can happen to an exciters polarity if there's a brush problem or a short circuit |
The polarity can be reversed |
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What are the designations of the primary and secondary windings of a transformer |
Primary is designated with an H Secondary is designated with an X |
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Which two categories do elevator control systems fall into |
Grounded control systems and ungrounded control systems |
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Which control system offers the best protection against an elevator operating in an unsafe manner because of an unintentional ground |
Grounded control system |
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How is synchronous speed determined |
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The difference in speed between synchronous speed and rotor speed is referred to as what |
Referred to as slip |
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Static drive is a term used to describe which kind of drive |
Silicon controlled rectifier drive |
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Which two ways can three-phase induction motor Fields be connected |
Wye or Delta |
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Does a static drive require an M.G. set |
No |
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What does the Ward Leonard drive consist of. |
A compound wound generator and a shunt wound motor |
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Dashpot overload relays and thermal bimetallic overload relays are used for what? |
They are used to protect motors from overload |
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What are the two currents on an AC relay called |
Inrush (high) and seal (lower) |
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What will happen if an AC relay is blocked from closing |
The relay coil will probably burn out |
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Grounding consists of which two categories |
System grounding and equipment grounding |
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The line side terminals in a disconnect are called? |
A B and C |
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What is used on a main line disconnect switch when an elevator is equipped with a rescue mode feature? |
An auxiliary contact |
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All fuses are rated by what |
Voltage and amperage |
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Which kind of fuse is used in transformer and motor circuits |
Time delay |
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How can you reduce contact arcing on plug-in relay contacts |
Wire two contacts of the same relay in series |
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How are latching relays reset |
Electrically |
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Collective control will do what with all calls |
Store them |
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What uses lines and symbols to show the arrangement of electrical circuits, components and connections for a job |
Straight line wiring diagrams |
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In a _______ -_______ control system, an elevator traveling up will not change directions until the highest of the register calls are answered |
Selective - collective |
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As current flows through a relay coil the _____ _____ generated by the coil will pull or pick the relays. |
Magnetic force |
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What is the most common relay used today in the elevator industry |
Plug-in type |
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How do the majority of today's set / reset relays work |
By using two independent coils mounted to a common relay base |
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What prevents two or more relays from becoming energized when they're picked electrically at the same time |
Interlocking contacts |
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What allows current to flow in only one direction |
Diodes |
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In a DC circuit diodes that have a negative voltage on the bar side of the diode when biased in which direction? |
Forward biased |
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Exciters are self excited generators. Their fields are compound wound, this means they have a? |
Shunt field and series field |
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Were early AC elevator brakes Superior to DC brakes |
No |
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When selectors use multiple stacks of contacts for each floor these contact assemblies or stacks are called what |
Pile-ups |
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Maintaining adjustment and lubrication of the moving parts of a mechanical _______ ______ is essential for proper operation |
Stepper switch |
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What is it called when a selector uses two motors that are electrically connected and in sync to each other |
Selsyn selector |
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Latching relays use which kind of latch to set and reset |
Mechanical latch |
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When the elevator controls use door zone switches with leveling switches, the door zone switch is frequently placed between the |
Level up and level down switches |
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What kind of timer is required on constant pressure push-button controlled elevators to eliminate the possibility of the elevator quickly reversing direction as it leaves the floor if a call is placed too close to the floor |
Non reversing timer |
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To avoid typical motor damage due to locked rotor, retiring cams use what kind of motor to operate? |
Torque or stall motors |
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Wiring diagrams that show graphic symbols, electrical connections, and specific electrical circuit arrangements are known as |
Schematics or straight line diagrams |
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Inline solid state timers are adjusted by setting what on the timer for the desired time needed |
Dip switches |
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In which configurations are hydraulic pump motors usually delivered |
6, 9 or 12 lead |
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Isolation of components during resistance testing is required to prevent false readings due to what? |
Parallel resistance |
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Three-phase rectifier |
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When using a digital multimeter, which jack is the red lead plugged into for all measurements except current? |
V ohm jack |
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When connecting a meter in a circuit to measure current, the meter will be damaged if ? |
If connected across a voltage source |
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What type of control was developed by Ward Leonard? |
Variable voltage DC control |
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Tapped relay coil with selector cancelling |
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What is the designation for the load side of a 3-phase main line disconnect switch |
L1 L2 L3 |
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What type of relay is mechanically held in once it becomes energized |
Latching relay |
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In a Ward Leonard voltage control system, what controls the voltage output of the generator? |
The voltage applied to the generator shunt field |
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What is the purpose of contact UD 41/43 |
An electrical interlock contact |
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The activation of which device will shut off power to the pump and return the car to the bottom landing |
The MT timer |
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Which control method can be used to control single and two speed AC induction hoist motors |
VVVF drives |
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What describes generators, controllers, hoist motors and raceways tied to a common safety? |
Bonding |
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What is the purpose of the BS contact |
Reduces brake current when fully picked |
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Which logic function initiates slow down for a call |
Stopping circuit |
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How are the car calls normally cancelled |
By opening the self holding circuit |
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What describes selective collective elevator control |
Answers calls sequentially in the direction of travel |
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How would you correctly measure AC current with a digital meter |
Function switch to A~, red lead in the 10A jack and black lead in the Com jack |
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How is voltage tested with an analog meter |
With the leads connected in parallel with the load |
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After removing power what else is necessary before testing resistance of a component in a circuit? |
Remove one lead of the component from the circuit |
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If fuse F1 was open, how is the voltage to the door operator effected? |
The voltage would decrease |
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What if an unintentional ground developed at terminal 5 when the car tries to run down |
Fuse 6 would open |
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What type of selector is used on the wiring diagram |
Notching switch selector |
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The car arrives at the top floor and the position indicator illuminates but the TF relay fails to energize, what could be the cause of the problem |
TF coil is open |
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What describes the operation of MT? |
Energizes after excessive up run |
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Single phase rectifier |
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Poly or 3 phase rectifier |
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The output voltage of a generator is controlled by what? |
It's controlled by the voltage applied to its fields |
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What is a commonly used method for generator field control? |
To have resistors in series with the generator field |
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What is one benefit we get from a self-excited shunt field? |
Smooth acceleration and a smooth ride |
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What are adjustments to the series field called? |
Compounding |
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Interpoles are used to reduce arcing of the commutator brushes on what? |
Both the generator and the drive motor |
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Any absorption in a circuit, tending to reduce the amount of stored energy is referred to as? |
Damping |
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Which kind of circuit would probably use an electrical interlock or walking beam |
Wye - Delta starting |
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What controls the door open cycle time? |
Timer T |
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What is the purpose of contact T1 11/13 |
Provides non-reversal time |
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If the main lobby smoke detector were activated, which relay would energize? |
AL and F1AL |
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What is the purpose of contact FH 21/23 |
To control constant pressure close of doors in phase 2 operation |
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You suspect that a coil is open and decide to test it. What is the correct procedure? |
Remove power, disconnect one of the coil leads and measure resistance |
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When testing voltage from points CP2 to CP3, what position should the digital multimeter be on? |
AC volts |
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What is the purpose of contacts T1 11/13 |
It provides non-reversal time |
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What controls the door open cycle time? |
Timer T |
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On-delay timing circuit |
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What is the function of the retiring cam? |
Actuate landing interlocks |
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When the car is at rest the bypass valve should be in which position |
Full open |
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What type of circuit |
On delay timing circuit |
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When the switche is closed, then opened, what will happen to relay one and relay two |
Relay one off delay, relay two drops immediately |
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If a ground occurred on contact A1 as shown, what would happen in the circuit |
The circuit will operate normally |
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If the car were running up in response to a third floor call, when would the U relay de energize |
When selector switch number three opens |
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If the car were at the second landing with no registered calls, which condition would be true |
UD relay would be energized |
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What type of door operation will take place if contact DR 1-2 fails to close |
The doors will open fully then close immediately |
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Which type of diagram provides a picture of the appearance and location of elevator parts |
Field wiring diagram |
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A single phase, full wave rectifier with 120 volts AC input will produce how much DC voltage |
108 VDC (90%) |
