ch 17
Even if a repair does not directly involve the electrical system, you must consider the location of electrical conductors and components to ensure that you are working safely.
True
The condition that exists when there is an unbroken path between two points in a circuit is called ____.
continuity
The ____ function on a multimeter allows a technician to test devices that conduct current in only one direction.
diode check
The ____ method of troubleshooting begins with a voltage measurement at the switching device near the middle of the ladder diagram rung.
divide and conquer
The ____ method of troubleshooting is most helpful on complex systems.
divide and conquer
A clamp-on ammeter requires the circuit to be broken to take a measure of circuit current.
false
A wattmeter is connected in parallel with the circuit being measured.
false
If a load device is not operating and the voltage across the device is 0 V, the problem can only be a short in the load device.
false
If a voltage check was incorrect, the device is faulty and requires no other checks.
false
In a dc circuit, an in-line ammeter's black lead is placed on the side of the load closest to the positive terminal of the circuit's power supply.
false
On a diode, the end closest to the anode is usually marked with a line or stripe.
false
The from control inward method of troubleshooting starts the line voltage and moves through each switching device.
false
The vertical lines in a ladder diagram identify the controls and loads located in a circuit.
false
Unlike in-line ammeters, ohmmeters are connected in series with the circuit or load being tested.
false
The ____ method of troubleshooting is used to determine the location of an open switching device.
hopscotching
In addition to measuring voltage, current, and resistance, digital multimeters can also be used to ____
measure capacitance check frequency Correct! All of the above. check diodes
In dc circuits, the ____ of the measured voltage is affected by the side of the load that each voltmeter lead is placed on.
polarity
The first location to perform a voltage check is ____.
terminals of the disconnect
To measure voltage polarity correctly in a dc circuit, a technician should place the voltmeter's red lead on the side of the load closest to ____ of the power supply.
the positive side
An insulation test should not be performed when a system is under vacuum because ____.
the reading will be inaccurate
A diode must be replaced if a meter registers a voltage for both meter lead configurations.
true
Connecting an analog voltmeter's leads to a dc circuit incorrectly will make the needle try to move backwards.
true
If a megohmmeter reading has decreased several weeks after motor maintenance, the compressor motor may fail soon.
true
If a voltmeter is used to measure the voltage across a length of conductor that has no resistance, there will be little or no voltage measurement.
true
If an in-line ammeter is accidentally connected in parallel, it may blow a fuse.
true
If both diode leads are left in a circuit when checking the diode, it may result in false readings.
true
In ac circuits, a voltmeter reads the voltage without regard to polarity because the current is constantly changing directions.
true
In the from load outward method of troubleshooting, voltage at the load device is checked first.
true
A(n) ____ is an instrument used to measure the true power used by a circuit or an electrical load.
wattmeter
Each horizontal line on a ladder diagram represents an individual ___
CIRCUIT AND LOAD
Which multimeter function allows a technician to test for an unbroken path between two points in a circuit?
Continuity.
The ratio between true power and apparent power in a circuit is always between ____.
0.0 and 1.0
In general, a megohm reading of ____ or higher indicates that the motor winding insulation is in excellent condition.
100 MW
Which of the following electrical instruments must be connected in series to take an accurate reading?
In-line ammeter
During which step of the troubleshooting procedure should you look for signs of prior melting and sparking at terminals and connections?
Initial inspection