TPC 210 Flashcards
When preparing an elementary diagram, all lines must be:
Numbered consecutively
Dimming high pressure sodium HID lamps can cause:
Color shift
When you test a three phase, delta connected winding with a compass, the compass will indicate alternating North and south polee when the pole phase groups are:
Connected properly
On a rewound three phase motor, occasionally an entire pole phase group may be accidentally reversed. This results in overheating and an increase in the:
Magnetic hum of the machine
In autotransformer input circuits, each input line should be:
Fused
A helpful piece of information to have when revising a control circuit is the _____ wire or relay number. This information keeps you from having to hunt through the schematic.
Last
The ____ circuit of an electrical schematic is the simplest part of the diagram and the easiest to follow.
Power
Planned lighting maintenance primarily consists of _____ to economize on labor, ____ to optimize light levels and space appearance and ____ to correct abnormalities in operation.
Group re-lamping; fixture cleaning; troubleshooting
Interchanging any two supply leads of a three phase motor:
Reverses the direction that the motor runs
If you see underlined numbers 6 and 12 at the end of a rung containing CR8, this indicates that there are _____ on lines 6 and 12.
N.C. CR8 contacts
A gaseous discharge lamp, such as a florescent or HID, requires a _____ to provide proper starting voltage and regulate current.
Ballast
When trouble shooting combination starters, the number one symptom of a problem is the operator saying, “The motor _____.”
Doesn’t run
A relay that has “dogs” located directly above the operating bar is called a:
Latching relay
The systematic testing of all controls in a building to ensure that they perform and interact properly is known as:
Commissioning
On a blueprint, wall outlets are indicated by a circle with a:
Short line drawn to it
Over voltage, excessive current and frequent operation are possible causes of:
Burned or short circuited magnet coils
Worn or damaged ball and roller bearings are easily detected by the:
Unusual noise they produce
Memory can be built into either a pneumatic or electric control circuit containing only monostable devices by using:
Feedback
On a reversing starter, mechanical interlocks are used to prevent both sets of three phase contacts from being operated at the same time. The closing of ______ operates a mechanism that prevents the closing of the opposite contactor.
One contactor
Which of the following would show where the power distribution system, ducts and manholes are located for a manufacturing plant consisting of several buildings?
Plot plan
All of the following are common reasons why a split phase motor makes a noticeable noise when operating, except:
Two little end play
Adding limit switches to the control circuit of a reversing motor provides:
Over travel protection
A circuit that provides under voltage release and has two wires connected to the pilot device that energizes the magnetic control circuit is said to have:
Two wire control
Most control cycle faults are remedied by locating and correcting:
Switching errors
In a shunt motor, the field windings are separately _____ so they carry just a fraction of the load current compared to the full load current of the series motor field windings.
Excited
A pneumatic shuttle valve is used for operating a conventional pneumatic _____ or electrical relay from either of two control sources
Valve
Which of the following is not typically used to identify conductors in a motor control circuit?
Colors
Which are most affected by over voltage
Slow speed motors
In the electronic timing relay, the time delay assembly is connected in:
Series with the relay coil
Deterioration in a selenium rectifier is indicated by:
A gradual rise in the input current
Which of the following is NOT a common cause of mechanical vibration?
Worn brushes
The ______ contacts on a motor starter provide a parallel path for the current to the coil.
Auxillary
The actual location and routing of circuits are shown on a:
Wiring diagram
Which type of occupancy sensor detects the difference in heat emitted by humans in motion from that of the background space?
PIR sensor
A sequence of operation consists of two elements:
A log and a graph
One of the best ways to learn about new equipment is to begin troubleshooting:
Before installation
Open circuits and split phase motors are most often caused by loose or dirty connections of the centrifugal switch. Sometimes noisy operation of the motor is caused by:
Worn centrifugal switches
A control panel layout shows the:
Physical arrangement of all components
Operating a heavily loaded motor at _____ can cause a high slip.
Reduced voltage
DC motors and generators have _____, which cause special problems not normally found in AC machines.
Commutators and brushes
Which of the following provides both overload protection and short circuit protection in one unit?
Combination motor starter
The kind of lubrication that should be used in a bearing is determined by the bearings:
Maximum operating temperature
When you arrive to troubleshoot a defective machine, the next thing to do after talking to the machine operator is:
Press the start button
In a pneumatic circuit a check valve allows flow and only one direction. In an electrical circuit, this function is performed by a:
Diode
The following symbol represents an ______ outlet in a ______.
Exit light: wall
Most equipment manufacturers adhere to some kind of standard for electrical prints and symbols, the most widely used is the one proposed by:
JIC
If an electrical machine has several problems, you should correct ______ problem(s) before trying the machine again.
Only one
A riser diagram shows the:
Power distribution wiring from input through output
An open armature winding in a DC motor is indicated by:
A decrease in speed
