HVAC final exam, unit 14 Correct 100%(Rated A+)

To control ice build-up on a heat pump outdoor coil in the heating cycle, a ____ is attached to a large diaphragm. - ANSWER Microswitch The heater in the thermostat control circuit in the cooling mode is active when the - ANSWER Cooling contact is open If the suction pressure of a system is 60 psi and the oil pump is 85 psig, what is the net oil pressure? - ANSWER 25 psig What is meant by the term "detent" ? - ANSWER opening or closing of a contact The heat anticipator in the thermostat control circuit in the heating mode is active when the ___. - ANSWER Heating contact is closed To obtain an accurate reading of a fluid in a large pipe, a technician should____. - ANSWER thermometer in a well T/F: The heat anticipator in a thermostat prevents the temperature in the conditioned space from rising above the thermostat settings - ANSWER True T/F: The advantage of using a thermistor-type thermometer over a mercury-filled thermometer for measuring refrigerant line temperature is that the thermistor-type does not have to be installed. - ANSWER False T/F: Natural gas fired heating units operate at a manifold pressure of 3.5" water column - ANSWER True T/F: A helix coil is used when in some applications to sense temperature in a moving air stream. - ANSWER True T/F: The cold anticipator starts the cooling system early to allow the air-conditioning system to get up to capacity when needed. - ANSWER True The heater that functions in a thermostat in the heating mode is called the - ANSWER Heat anticipator The term used to describe when the temperature of a heated room falls below the thermostat's set point is called - ANSWER system lag The term used to describe when the temperature of a heated room rises above the thermostat's set point is called - ANSWER system overshoot The heater that functions in a thermostat in the cooling mode is called the - ANSWER Cold anticipator What type of control would be used to cycle compressors on and off in response to evaporator pressures that indirectly control box temperatures? - ANSWER Low pressure control What device may be used to ensure that air is flowing through a duct before an electric