A technician has determined a supply in a flexible duct system is leaking. What should be checked? -
ANSWERAll connections inner and outer layers.
Electronic air cleaners can operate with internal voltages as high as? - ANSWER5000v
Why do some electromechanical type thermostats require connections to both the hot side and
common side of the low voltage transfromer - ANSWERDisplay lights must be powered using both
sides of the line
the continuity reading on a functional fuse will be - ANSWER0 ohms
a compressor with proper voltage and a hard start relayt and capacitor draws lock rotor amps on
startup. what is the problem? - ANSWER
the technician believes that a hermetic compressor has a permanently openn internal overload
protectio the technician should test the compressor while it is? - ANSWERcool
outdoor condensing units that are installed in areas where flooding is possible must - ANSWERbe
mounted above flood level
In a low voltage circuit, a corroded wire-to-terminal connection acts in the circuit like an -
ANSWERadditional resistor
a system with a reciprocating compressor is pumped down and the power is shut off. if the suction
pressure rises very rapidly this is an indication that the - ANSWER
if an air conditioning system needs to operate in a low ambient condtion, the condenser may
become to effiecent - ANSWERthe head pressure becomes too low and the condenser fan motor
needs to be slowed or stopped
to achieve a specific seer rating which components must be matched - ANSWERcondensing unit and
evaporator
, on a residental no cooling call, typically the first check would be - ANSWERif the thermostat is calling
for cooling
in an economizer system the enthalpy control is used to measure - ANSWERboth temperature and
moisture content
an air conditioner refriderant circut should be evacuated to a minimum of - ANSWER500 microns
what steps are necessary to clean a two row curved condenser coil - ANSWERseparate the two rows
of coils, spray all surfaces with proper coil cleaner and water flush
in a simple refrigeration system the refriderent boils in the - ANSWERevaporator
electronic air cleaners do not remove - ANSWERanimal fur
a delay on make relay delays load from - ANSWERfrom energizing after a fixed time after a cycle
return air leakage in a hot attic will - ANSWERdecrease capacity
When a split system air conditioner has a counterflow air handler, what are the best locations for
return air grilles? - ANSWERon a sidewall next to the ceiling
the lubricating oil primarily ised with r-22 is - ANSWERmineral oil based
other than using a two-stage compressor what is another method for capacity control -
ANSWERliquid line receiver
a system air flow check is used to diagnose - ANSWERhumidity problems
what precautions need to be taken with a packaged ac system with ductwork installed outside -
ANSWERit must be insulated and weatherproofed