Unit 15 Flashcards
Questions 1-12 based on pictorial schematic
Use diagram to answer questions
Heat contacts _______ on the rise in temperature and close on the _______ drop in temperature
Open on the rise and close on the drop
What can be done if an older clamp on a meter cannot measure low current in a circuit?
Wine 10 coils of wire and measure. The result should then be divided by 10 for current reading. 
Defrost can be terminated by ______ or ________.
Time or temperature
Two distinct types of wiring schematics/diagrams are furnished with equipment. What are the diagrams called? 
Ladder Diagram and Pictorial Diagram
Unit containing compressor, evaporator, condenser and me during device all in one unit such as a window air conditioner.
Package air conditioner
Uses power and have either a magnetic coil, or a resistant circuit referred to as loads.
Power consuming devices
Wired in series in the heat relay coil circuit (heat anticipator) resistor that can vary its resistance.
Variable resistor
Closes a set of contacts in the high-voltage circuit that starts the indoor fan
Fan relay coil
Side nearest the power source
Line side of the switch
Voltage measured across the start winding in a single face motor while it is turning at full speed. Difference in voltage between any two parts of a circuit. 
Potential voltage
Side of the switch the load is connected
Load side of the switch
Passes power on power consuming devices
Non-power consuming devices
A magnetic coil is energized initiate a heat cycle
Electrical heat relay
Short piece of wire with alligator clips or connector on each end used to bypass components in an electrical circuit. Wire gauge should be large enough to handle current in circuit. 
Insulated jumper
Wired in parallel to cooling contacts, non-adjustable resistor
Fixed resistor
T/F
The defrost termination solenoid is often referred to as a “Z” coil
True
T/F
The ladder diagram is easier to use for locating the different components in the circuit 
False
T/F
Jump terminals R and C in the thermostat subbase to energize the heating coil 
False
T/F
Divide a transformers capital VA rating by the primary voltage to determine the maximum the current transformer can handle before the low-voltage fuse is blown 
False
Divide VA by lower voltage in transformer
T/F
If there is voltage at the light socket, and the lightbulb fails to illuminate, the bulb is bad 
True
T/F
If Line 1 of a circuit had a potential of 120 V and Line 2 was neutral, the potential voltage (difference) between Line 1 and Lone 2 would be 0 V 
False
T/F
The cooling anticipator is bypassed from the circuit when the thermostat is satisfied/opened 
False
T/F
While troubleshooting a 24 V circuit consisting of a thermostat, a pressure control, and a contactor coil, the technician reads 24 V across the thermostat, 0 V across the pressure control, and zero votes across the contact coil. The technician makes the following statements.
A)The transformer is burned out
B)The thermostat is open
C)The contractor coil is energized
D)The pressure control contacts are closed
False
Electrical controls are divided into two categories: power passing and _________
Power consuming
While checking a simple series, 115 V circuit, containing a fuse, a switch and a lightbulb, the technicians voltmeter reads 115 V across the lightbulb socket. The lightbulb is not on. He correctly includes the ________is defective.
Bulb
Draw the ladder diagram for an evaporator fan motor with a switch that turns the fan on/off. Power supply is 115 V.
Questions 39-43 use diagram to draw path of current and answer questions
If a circuit has a current draw of 0 amps, is the load energize?
No
