CERTIFICATION QUESTIONS WITH ACCURATE ANSWERS
A cyllinder of R-410a stored at 70 degrees F should show what pressure? correct
answer 200.8 psig
A manifold gauge is properly connected to the suction and discharge valves on a
compressor, in order to read the high and low side, what position should the
gauge manifold valves be in? correct answer n order to read the high and low side
pressures in the system, the valves should be fully clockwise
A system with a thermostatic expansion valve (TXV) will try to maintain a
constant..? correct answer Superheat
A system with an automatic expansion valve (AXV) will try to maintain a
constant...? correct answer Evaporator Pressure
An automatic expansion valve (AXV) directly controls..? correct answer
evaporator pressure
An evaporator coil should be selected to match...? correct answer the outdoor
coil
An inefficient or worn compressor will be indicated by what suction and discharge
pressures? correct answer High suction pressure, and Lower discharge pressure
Condenser split is? correct answer Range at which condenser operates
Example: Condenser operates at 120/90 degress F
, Define compression ratio: correct answer Pressure difference; High-side absolute
pressure DIVIDED by the low-side absolute pressure.
Define liquid slugging: correct answer a large amount of liquid refrigerant in the
compressor cylinder, usually causing immediate damage.
Define specific heat: correct answer The amount of heat necessary to raise the
temperature of 1 lb of a SUBSTANCe by 1 degree F
Define subcooling correct answer Subcooling is the process by which a saturated
liquid refrigerant is cooled below the saturation temperature, forcing it to change
its phase completely
define volumetric efficiency: correct answer the pumping efficiency of a
compressor that describes how much refrigerant (capacity) it holds versus how
much it actually pumps through. Compressor effectiveness
During a condensate drain installation, how much vertical distance is allowed
from drain outlet to P-trap? correct answer 2"-3"
For proper comfort conditioning, what is the recommended summer indoor
humidity level? (percent) correct answer standard for 70 degrees F= 60% relative
humidity
Give more than one equivalent of "zero PSIA" correct answer 29.92 in Hg vacuum,
0 microns