Electricity finals
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| In replacing a ____ it is desireable to use an exact replacement this means a ____ with the same MFD rating and voltage limit rating. | Capacitor
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| ___ Controls are nonelectric and opperated by air pressure | Pneumatic Controls
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| In this diagram for observing the sequence of operation is _____ ______. Is represented by vertical lines shown as L1 and L2 | Ladder Diagram
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| An example of a ____ ____ is a room thermostat. When the Thermostat calls for colling the AC Unit begins to run The direct action of the control starts or stops the unit. An example of an indirect control device is the low pressure switch and arngment of | Direct Control
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| Fan Motor, Damper, Compressor, Contactor, Pumps, Valves, Relays, Ventilator | Controlled Devices ( Loads)
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| Thermostat, Humidistat, Fan Switch, Overload, Pressure Switch, Defrost Timer, Head Pressure Control, Low Ambient Control, these are all.. | Control Devices (Switches)
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| A ___ is an example of an auto control device. | Thermostat
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| Where fuses are used to protect motors in the circuit, a special type of fuse is used called a ___ ____ fuse or dual element fuse. | Time Delay
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| ___ are constructed using the induction characteristics of AC Power. | Transformers
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| A Characteristic of electromagnetism is its ability to induce a current flow in another conductor that passes through its magnetic field. This is known as ___. It is useful in the design of transformers, motors, and generators | Induction
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| When the current flows through the coil the rod tends to center its self in the coil. This principle can be used to opperate a switch. This arrangement is useful in the construction of relays, ____, ____ ___, and motors | Contactors, Solenoid Valves & motors
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| Anytime the current flows through a ___ it creats a magnetic field around it to intensify the field, The ___ is coiled | Conductor
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| DO NOT interchange ___& ___ Capacitors. ___ capacitors are high capacity (100-800 MFD) electrolytic units that are intended for a mometarilly use in starting motors. & Normally incased in plastic. ___ capacitors have much lower capacitance ratings 2-40mfd | Start Capacitors, run capacitors
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| Controls are required to start, stop, regulate & ptotect the refrdg. cycle & its components. Many controls today are electric or electronic ___controls. Commonly in com. bldgs. the 4 basic types are Thermostat, Pressurestat, Humidistat & the time clock. | Pneumatic controls
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| The ___ ___ ___ is used to stop the compressor at a predetermined minimum opperating pressure. | Low Pressure Control
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| Prob. the best example of a pressure control used for safety purposes. ___ ___ ___ can be set to stop the compressor before excessive pressures are reached. | High Pressure Cutout
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| The oil safety switch is designed to protect against the loss of ___ ___ | Oil Pressure
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| Bimetallic disks are another type of electrical ___ ___ | Overload Protector
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| Electrical overloads provide for protection against ___ ___. | Excessive Current
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| It is never acceptable to ____ across a safety device | Jumper
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| Controls protect the cycle & its components from damage. | Safety Controls
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| Opperating controls are ___, ___, & ___ controls that are used to opperate the system after it is started. | Electrical, Pneumatic, Mechanical
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| RELAY, STARTER, CONTACTOR. These devices consist of 2 parts: A coil that is energized when the primary control closes and one or more switches that change position when this occurs dif. betw. the 3 devices is mainly size. the starter is a contact w/ __ __ | Overload Protection
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| Another electrical control. Detent, or ___ action; Typically, all electrical contacts should be opened and closed quickly & cleanly. | Snap Action
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| The ___& ___ points cannot be the same or the control would chatter. The difference between these points is the differential. | Cutout & Cutin Pts.
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| ___ is the difference between the min. and the max. opperating points within which the control will function accurately. | Range
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| The 3rd type of basic control is the humidity control or humidistat. ___ elements are used on these controls, the most common is human hair | Hygrospopic elements
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| Pressure controls can be divided into 2 catagories: The ___ type & the ___ ___ type | Bellows type Bourdon tube type
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| The great advantage of the electronic Therm. is its accuracy. It will control the temp. within 1 Degree F. for comparison the ___ thermostat controls to an accuracy of about 2 Degree F. | Bimetal Thermostat
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| This is a sensing element for an electronic thermostat. The ___ has a resistance element that is affected by temp. | Thermistor
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| The Pushing that causes electrons to flow is | Current
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| The unit of measurement for current flow is? | Ampere
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| Loads are considered as | Voltage Sources
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| The coil of a wire with moveable iron core is referred to as a | Contactor
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| The part of a transormer that consumes energy to produce magnetism is called | The Primary Winding
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| When there is more voltage in the secondary winding than in the primary winding, the transformer is called | A delta Transformer
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| An undergrounded conductor is known as the | Hot Leg
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| The formula "VA= VxA is used to determine | The rating of a transformer
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| The Neutral is known as the | Grounded conductor
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| The two basic configurations for transforers are | Single Phase and Polyphase
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| in the 240/120 VAC 60 cycle power source the voltage between L1 and Neutral is | 120 Volts
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| The opposition to the movement of magnetic lines of force is called | Electromotive Force
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| In order to beneficially use a voltmeter, what must you do before measurements are taken? | Turn the power on.
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| Reading voltage across the load indicates | A complete circuit to the load
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| The most important thing to do when using a ohmmeter to test a circuit | Turn off the power to the circuit being tested.
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| Electronic air filters are commonly operated with | D-C power
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| Electron flow is measured n | Amps
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| Electronic air filters are commonly operated with | D-C power
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| Electron flow is measured in | Amps
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| What type of motor is usually rated at less than 1/2 HP | The shaded pole motor
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| The voltage induced into the start winding of a motor is called | Back EMF
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| An overload that breaks the control circuit is called | Pilot Duty
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| The secondary side of a transformer | Has voltage induced into it
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| Potential is also known as | Electromotive Force
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| Run Capacitors range in size | 2-80 MFD
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| Which transformer will have a Wild Leg? | Delta 4 wire system
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| The opposition to the movement of magnetic lines of force is called | Reluctance
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| The coil resistance of the current start relay | Zero Ohms
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| The potential start relay is wired | In parallel with the motor start winding
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| The motor which uses a current relay to remove the start winding from the circuit is called | RSIR
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| In the PSC motor , the run capacitor is wired | In series with the start winding
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| When using a PSR, terminal 5 of the relay is connected to | The common terminal
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| When wiring the dual winding motors line voltage is connected | to the run and common terminals
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| The highest motor winding resistace will be found between | The run and start winding
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| The lowest motor winding resistance will be found between | The common and the run windings
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| Connecting capacitors in parallel will cause their MFD rating to | Add
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| An under sized run capacitor will cause | The motor run winding to draw higher than normal amps.
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| An over sized run capacitor will cause | the motor start winding to draw higher than normal amps
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| In pilot duty overload, the switch portion opens | the control circuit to the motor
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| The 3 phase motor, single phasing occurs when | The voltage is lost to one phase of the motor
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| The max voltage unbalance in a 3 phase motor is | 2%
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| The max current unbalance in a 3 phase motor is | 10%
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| In a line duty overload, the switch portion is wired | In series with the motor
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| If theoverload in a PSC motor opens, what resistance reading would you have between the common and run terminals of the motor? | Infinite resistance
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| __ is the measurement of the Potential difference | Voltage
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| What motor requires no AUX windings, and no switching circuits. | 3 phase motor
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| ___ Force or potential is the ability to make current flow | Electromotive force
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| The rate of electric current fkiw is measured in? | Amperes
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| The other 5 forms of energy that can be used to generate electricity are | Chemical, heat, light, magnetic, mechanical
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| The phaseshift factors are | Inductive circuit, resistive circuit,capacitive circuit
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| The __ circuit contains at least one __ load, such as an electric heater or lamp | Resistive Circuit
Resistive Load
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| The __ is an electrical device that is used to change the phase relationship between the current & voltage | Capacitor
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| Opperating controls are __, __, &___ controls that are used to operate the system after it is started | Electrical, Pneumatic,& mechanical controls
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| These devices consist of 2 parts: a coil that is energized when the primary control closes and one or more switches that change position when this occurs. | Relay, Starter, & Contactor
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| These devices provide either current protection or temperature protection. They use bimetal disks and reset automatically after recovering from the overload condition | External Suppliment Overload or Current Temp.
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| In a __ __ motor, a pilot duty device senses current overload or excessive temp. Within the motor, and opens the contactor circuit to remove the power to the motor. | 3 phase motor
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| On a __ __ motors, if the voltage varies more than 2% between phases, the life of the motor will be reduced | 3 Phase motor
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| Typically motors are designed to be applied withing +-10% of the __ ___ voltage | Name plate
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| The __ __ current is the momentary starting current. This can be 3 to 5 times the running current of the motor | Locked rotor
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| __ reads true power including an allowance for the power factor | Wattmeter
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| Ohmeters measure the electrical resistance and can be used to check the circuit for ___ | Continuity
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| __ are used to measure current flow through a circuit. | Ampmeters
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| Voltmeters are connected in paralell with the load to read the voltage drop or __ difference | Potential
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| A Wattmeter is used to measure electrical __ | Power
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| An Ohmmeter is used to measure electrical__ | Resistance
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| A Capacity checker is used to measure Capacity __ capacitance | Microfarad (MFD)
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| Voltage= E= Electromotive force |
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| Amperes= I= Intensity |
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| Watts= p= Power |
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| The PTC is a temp. sensitive device whose electrical __ will increase as it's temp. increases | Resistance
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| Fewer electrons in their outter ring__ | Insulators
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| Measure the rate of current_ | Ampere
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| Measure of potential difference__ | Voltage
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| Measure of electrical work__ | Watt
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| A circuit without a load | Short circuit
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| More than one path for the current to flow__ | Paralell circuit
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| 40 VA& 1.6 amps | Transformer
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| We draw switches in the __ position | De energized
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| the phase shift factors are | Resistive Circuits, Inductive circuits, capacitive circuits
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