All rights reserved. Printed in the United States of America. Page 4 a word that matches the picture (Listening Comprehension standard score = 84) and generate words within a category, describe scenes, and give directions (Oral Expression standard score = 83).
The power is supplied by a transformer, and when the thermostat makes contact between the 24 volt power and one or two of the other wires, a relay back at the heating/cooling unit activates the corresponding heat/fan/cool function of the unit(s).
The thermostat does this by switching heating or cooling devices on or off, or regulating the flow of a heat transfer fluid as needed, to maintain the correct temperature. A thermostat may be a control unit for a heating or cooling system or a component part of or air conditioner.Thermostats can be constructed in many ways and may use a variety of sensors to measure the temperature.The output of the sensor then controls the heating or cooling apparatus.he thermostat does this by switching heating or cooling devices on or off, or regulating the flow of a heat transfer fluid as needed, to maintain the correct temperature. A thermostat may be a control unit for a heating or cooling system or a component part of or air conditioner.