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 calls for heat, sending DC current to the furnace. 2. A Time Delay Relay is energized and passes battery DC power to the blower motor. 3. The blower motor and fans spin, pulling air from the Air Return and generating a stream. of air through the Heat Exchanger and out the Ducts.