NATE Heat Pump Pretest Exam and
Answers
The voltage most often used to power the outdoor unit in a residential system is - ✔✔240 volt
single phase
What is the possible result of using control wire smaller than 18 gauge - ✔✔Decreased voltage
could occur at the thermostat or operating equipment
On some installations, a heat pump indoor coil can be installed on an operable fossil fuel
furnace. When this type of installation is done, what precaution must be taken - ✔✔Add a
control so that the furnace and heat pump do not operate at the same time in normal heating
The water the results from a defrost cycle of an air to air heat pump must drain off and away
from the outdoor coil. What can happen if the defrost runoff is not properly drained away -
✔✔Excessive ice can build up on the bottom of the coil and reduce capacity
When changing out an outdoor unit of a spilt system heat pump, a critical factor to check on
the new unit is that - ✔✔There is adequate clearance on all sides and the top of the new unit
The timer best suited for preventing thermostat short cycling of a compressor is a - ✔✔Time
delay relay
In a heat pump system, the refrigerant boils in the - ✔✔Evaporator
An externally equalized thermostatic expansion valve has a fitting for connection of a copper
tube to the outlet of the evaporator coil. What is the purpose of this connection - ✔✔It allows
the valve to properly sense evaporator pressure at the TEV bulb location
Drive cleats are typically installed where on rectangular duct - ✔✔On the shorter sides
Answers
The voltage most often used to power the outdoor unit in a residential system is - ✔✔240 volt
single phase
What is the possible result of using control wire smaller than 18 gauge - ✔✔Decreased voltage
could occur at the thermostat or operating equipment
On some installations, a heat pump indoor coil can be installed on an operable fossil fuel
furnace. When this type of installation is done, what precaution must be taken - ✔✔Add a
control so that the furnace and heat pump do not operate at the same time in normal heating
The water the results from a defrost cycle of an air to air heat pump must drain off and away
from the outdoor coil. What can happen if the defrost runoff is not properly drained away -
✔✔Excessive ice can build up on the bottom of the coil and reduce capacity
When changing out an outdoor unit of a spilt system heat pump, a critical factor to check on
the new unit is that - ✔✔There is adequate clearance on all sides and the top of the new unit
The timer best suited for preventing thermostat short cycling of a compressor is a - ✔✔Time
delay relay
In a heat pump system, the refrigerant boils in the - ✔✔Evaporator
An externally equalized thermostatic expansion valve has a fitting for connection of a copper
tube to the outlet of the evaporator coil. What is the purpose of this connection - ✔✔It allows
the valve to properly sense evaporator pressure at the TEV bulb location
Drive cleats are typically installed where on rectangular duct - ✔✔On the shorter sides
