Unit 16 Flashcards
What are the three basic components that make up a control loop?
Sensor, controller and control device
What is the difference between a close loop and an open loop system?
Open: inputs are before the controller
Close: inputs are after the controller, and Kenmore accurately adjusted changes made at the controller
Active sensor and information back to the controller in terms of _______ or _______.
Mili-amps or volts
Determine if the device is a controller, control, device, or sensor
Damper
Controlled device
Determine if the device is a controller, control, device, or sensor
Thermistor
Sensor
Determine if the device is a controller, control, device, or sensor
Valves
Controlled device
Determine if the device is a controller, control, device, or sensor
Thermostat
Controller
Determine if the device is a controller, control, device, or sensor
Humidistat
Sensor
Determine if the device is a controller, control, device, or sensor
Variable speed motor
Controlled device
Determine if the device is a controller, control, device, or sensor
Proportional Integral Derivative
Controller
Determine if the device is a controller, control, device, or sensor
Anemometer
Sensor
A passive sensor sent information back to the controller in terms of ________.
Resistance
The section on/inside the controller allows the microprocessor or digital controller to read the incoming data 
Signal converter
Give two examples of a binary (digital) input
-High pressure switch and low pressure switch
-on or off
-left or right
T/F
The more poles a motor has the faster, the speed of the motor
False
T/F
The control device’s location determines if the control loop is open or closed
False
T/F
The small switches in the back of a thermostat are called dual in-line pair 
True
T/F
Pneumatic controls can be used to switch electrical circuits
True
T/F
Control loops can only maintain one sensor input. If a room needs light intensity, temperature and humidity controlled, three control loops are required. 
True
T/F
Space temperature is not the only temperature that is important in modern systems 
True
What are four other temperatures that may be used to make an air-conditioning system operate, more efficiently and economical?
-Ambient temp
-Indoor temp
-Supply air temp
-Return air temp
-Motor winding temp
-Discharge line temp
-Suction line temp
Questions 22-33
Use the diagram to picture an open or close loop system. Be able to place sensors in the right location to make them open or closed loop.
The internal instructions on a control board are stored in the _________.
Central processing unit
Draw a ladder diagram showing a thermostat closing on the rise to pass power to a control, relay and liquid line solenoid that are wired in parallel. System power is 120 V.
What are two types of dryers used to remove moisture from the air used in a pneumatic control system? 
-refrigerated air drier
-inline desiccant filter drier
How much change in output per degree of temperature change
Sensitivity
Reduce electrical power consumption by shutting down or reducing use of equipment during slow periods
Load shed
Controls that use solid-state semi conductors for electrical and electronic functions
Electronic control
Consist of sensor, controller and controlled
Control loop
Controlling the flow between maximum or no flow
Modulating flow
A continuous signal with an infinite number of step
Analog signal
Air used as a control
Pneumatic control
Sensitivity of a Control, such as how much change in output signal per degree of temperature
Gain
Electronic control that operates on very low voltages
DDC
Load shedding or duty cycling to lower electrical power costs
Energy management
Used to control large volume of air that must be used to operate large pneumatic devices
Pilot positioner
Codes that read out on an electrical panel that tells technician what the problem is
Error codes
Start up of a building AC or heating system whereby the system is started up earlier and allowed to run at reduced capacity for the purpose of recording a low demand metering for the billing period
Smart recovery
Modulating flow means ______.
A, B, C, D multiple choice
Variable
Is it normal to hear a hissing sound when walking by a pneumatic thermostat?
Yes. Although a constant loud hissing could mean an air leakage which will need to be addressed. 
Temperature, pressure, flow, light and humidity are all examples of _______ inputs
Analog
Convert 60°C to Fahrenheit
140°F

Be able to draw ladder diagrams for given circuits (two different diagram examples)
