Type 1
According to the EPA, a small appliance is?
A system containing under 5 lb of refrigerant or less including PTACs.
After the installation of a refrigeration system, the technician should first?
pressure test the system using nitrogen.
What is the easiest way to leak test a low-pressure system?
add warm water over the coil to raise the pressure to 10 psig
What may cause a pungent odor in a CFC/HCFC system?
a burnt compressor
What methods help to reduce recovery time of a system?
pack ice around the recovery tank, heat the appliance, and recover liquid first
Under conditions of ARI 740-1993, recovery devices manufactured before November 15, 1993, must ?
be able to remove 80% of the refrigerant charge or achieve 4” Hg vacuum.
What maintenance task must always be done to recovery/recycle equipment?
change system’s oil and filters
When using an electronic leak detector, where is a water box leak tested after the water has been removed?
at the drain valve
Which refrigerant requires a separate set of gauges, a vacuum pump, and a recovery machine when servicing?
R-134A
During a recovery, when should the refrigerant be removed from the condenser outlet?
when the condenser is below the receiver
Technicians must certify their recovery equipment with the EPA after?
August 12, 1993.
An open compressor that has sat for several months is most likely?
to leak from the shaft seal.
How is refrigerant added to a low-pressure chiller after an evacuation?
by the use of the evaporator charging valve
If refrigerants are exposed to open flames and hot surfaces, what happens?
phosgene gas and hydrochloric hydrofluoric acids are produced.
What must be done to an empty recovery cylinder before transferring refrigerant into the cylinder?
it must be evacuated.
While recovering refrigerant, why is it necessary to install a piercing valve on both the high and low side of an appliance that has an inoperative compressor?
it will decrease the time of the refrigerant recovery
Why is it likely for a recovery and recycle machine to overheat when drawing a deep vacuum?
because the refrigerant is needed to cool the compressor
What is used when leak testing a water tube on a low-pressure chiller?
a hydrostatic tube kit
When using recovery and recycling equipment manufactured after November 15, 1993, technicians must evacuate an appliance containing more than 200 lb of HCFC-22 to what level before making a major repair?
10” Hg
When using recovery and recycling equipment manufactured before November 15, 1993, technicians must evacuate an appliance containing less than 200 lb of HCFC-22 to what level before making a major repair?
0 psig
After installing a piercing valve onto a system, you must?
leak test the valve.
Two indications that a high-pressure system has a leak are?
oil traces on flared fittings and high superheat.
What does the ASHRAE guideline 3-1990 state about a vacuum test?
If a 1 mm Hg vacuum level rises to 2.5 mm Hg, the system should be leaked tested.
A technician must never do what with a service valve?
front seat the discharge service valve while the compressor is in operation.
To prevent freezing when charging R-12 into an evacuated system, it must be in the vapor form to raise the pressure up to?
33 psig.