motor control final Exam Questions and Answers

A danger signal word on a warning sign is used to indicate a situation which ... - Answer- results in death Fuses should be installed ___ when replacing fuses - Answer- load side first rags containing oil, gasoline, alcohol, ... must be _ - Answer- metal container a _ drawing shows the physical details of an object as seen by the eye - Answer- pictorial in a line diagram, the power circuit is shown in _ lines than the rest of the diagram - Answer- heavier a _ diagram is used to show the relationship between circuits and their corresponding components but not the actual location of the components - Answer- line a pushbutton is an example of a(n) _ control switch - Answer- manual A float switch is an example of a(n) __________________ control switch. - Answer- automatic a line diagram is always read from _ to _ - Answer- l1 l2 a _ is used for remote control of devices - Answer- aotb when motors were first introduced, they were started and stopped by _ - Answer- knife switches one of the advantages of using a double break contact instead of a single break contact is that the double break contact _ - Answer- higher contact rating smaller space _ power line(s) must be broken when using a contactor to control a 3 phase load - Answer- 3 _ are used to help confine, dividce, and extinguish arcs for each set of contacts - Answer- arc chutes _ are used to provide a magnetic field that helps move contact apart as quickly as possible - Answer- blow out coils The power rating of a contactor or motor starter ___ as the NEMA number (Size 1, 2, etc.) of the contactor or motor starter increases. - Answer- increases the current rating of a contactor or motor starter is the rating for _ - Answer- each individual contact ___ contactor assemblies are made of laminated steel. - Answer- ac as ambient temperature increases, _ current is needed to trip overload devices - Answer- less in a transformer, a marking of x1 or x2 indicates the _ voltage side - Answer- low the function of a substation include _ - Answer- aotb always remove the _ side of a fuse first when removing fuses from circuits - Answer- hot/line class _ fires consist of burning wood, clothing, or paper - Answer- a class _ fires consist of burning electrical equipment - Answer- c class _ fires consist of flammable liquids such as gasoline and oil - Answer- b class _ fires consist of burning combustible metals such as magnesium or aluminum - Answer- d a(n) _ is a confined space that has specific health and safety hazards associated with it - Answer- permit-required confined space an oxygen content of 12% to 14% by volume results in: - Answer- oxygen deficiency symptoms lockout is the process of _ - Answer- locking out the electrical source _ is the connection of all exposed non-current-carrying metal parts to the earth - Answer- grounding a(n) _ derived system is a system that supplies electrical power derived (taken from) transformers, storage batteries, solar photovoltaic systems, or generators - Answer- separately a(n) _ bonding jumper is a connection at the service equipment that connects the equipment grounding conductor, the grounding electrode conductor, and the grounded conductor (neutral conductor) - Answer- main a(n) _ grounding conductor is an electrical conductor that provides a low-impedence ground path between electrical equipment and enclosures within the distribution system - Answer- equipment a(n) _ conductor is a conductor that has been intentionally grounded - Answer- grounded a(n) _ is a confined space that does not contain or have the potential to contain any hazards capable of causing death or serious physical harm - Answer- non-permit confined space _ rubber matting is specifically designed for use in front of open cabinets or high-voltage equipment - Answer- dielectric black fluted a danger tag is used alone only when _ - Answer- lock doesn't fit the disconnect device a paint spraybooth interior would be classified (under article 500 of the nec) as _ - Answer- class 1 division 1 in a line diagram, the overload contacts are shown as connected between the motor and - Answer- l2 a(n) _ is a device that converts various forms of energy into electricity - Answer- power source a(n) _ is an electrical device which consists of a frame, plunger, and coil and is used to create a push or pull action - Answer- solenoid a(n) _ is an electrical device which consists of a frame, plunger, and coil and is used to open and close a set of contacts - Answer- contactor a(n) _ is an electrical device which consists of a frame, plunger, and coil and is used to open and close a set of contacts in addition to providing overload protection - Answer- motor starter _ contacts are used in the control circuit to form an electrical holding circuit - Answer- normally open aux a(n) _ diagram is a diagram that shows the electrical connections and functions of a specific circuit arrangement with graphical symbols - Answer- schematic for consistency, the _ symbol is always drawn in a line diagram after the motor - Answer- overloads a(n) _ is an assemblage of conductors and electrical devices through which current flows - Answer- electrical circuit magnetic motor starter overloads have _ which sense excessive current flow to the motor - Answer- heaters _ diagrams show, as closely as possible, the actual location of each component in a circuit - Answer- wiring when troubleshooting electrical control circuits, the _ circuit must be checked against the circuit diagram - Answer- actual a(n) _ control circuit is a circuit that requires a person to initiate an action for the circuit to operate - Answer- manual loads must be in _ when more than one electrical load must be connect in a line diagram - Answer- parallel control relays, solenoids, and pilot lights are loads connected directly to lien _ - Answer- l2 a(n) _ is a load that is connected indirectly to line 2 through overload contacts - Answer- operating coil load in a line diagram, pushbuttons, limit switches, and pressure switches are connected between line 1 and the _ - Answer- operating coil load _ systems help to quickly identify the location and type of contacts controlled by a given device - Answer- numerical cross reference each wire in a control circuit is assigned a(n) _ to keep track of the different wires that connect the components in a circuit - Answer- wire number a control circuit is composed of three basic actions, which are the signal, decision, and _ sections - Answer- action the _ section of a control circuit starts or stops the flow of current by closing or opening the control device contacts - Answer- signal the _ section of a control circuit determines what work is to be done and in what order the work is to occur - Answer- decision the _ section of a circuit causes work to take place - Answer- action a(n) _ condition refers to any input into a circuit by a person - Answer- manual a(n) _ condition refers to any input into a circuit by some moving part - Answer- mechanical