AND ANSWERS SURE A+
✔✔After reaching the required recovery vacuum on a low-pressure appliance ___ _ ___
_____ to see if the system pressure ____ before charging. - ✔✔Wait a few minutes :
rises
✔✔When leaks in the appliance make evacuation/recovery to the prescribed level
unattainable, __ ___ _______ with the recovery. - ✔✔do not proceed
✔✔Recovery and recycling equipment must be _____ as certified to meet EPA's
requirements. - ✔✔Labeled
✔✔Replacing or repairing a _______, _______, or ________ is considered a major
repair. - ✔✔Compressor : condenser : evaporator
✔✔When making a non-major repair, warming the liquid refrigerant in the system with
_____ _____ or _____ ______ will bring the system pressure out of a vacuum - ✔✔Hot
water : warming blankets
✔✔Before disposing of a low-pressure appliance, the refrigerant must be recovered or
evacuated to ______. - ✔✔25 mm of Hg absolute
, ✔✔Recovery records for disposed appliances with 5-50 lbs of refrigerant must be kept
for ______ - ✔✔3 years
✔✔Before evacuation/recovery or dehydrating an oil sample should be taken if the unit
has had a _____ _______. - ✔✔Compressor burn-out
✔✔When evacuating/dehydrating a system that contains a large amount of moisture,
_____ evacuate/dehydrate the system using ________ to break the vacuum. - ✔✔triple
: dry-nitrogen
✔✔Increasing the pressure with nitrogen will prevent the moisture from _______. -
✔✔Freezing
✔✔After servicing and evacuating/dehydrating a chiller, ________ ____ is __________
into the chiller to a pressure which corresponds to its saturation temperature above
freezing. - ✔✔Refrigerant vapor : re-introduced
✔✔This will prevent liquid refrigerant charged into the system from freezing water in the
_____ _______ ____ _____. - ✔✔Heat exchanger tube bundle
✔✔When reviewing the saturated conditions on a PT chart, an evacuated/dehydrated
water-cooled chiller system with R-123 should have a vapor pressure above ______
vacuum before adding liquid refrigerant. - ✔✔20 inches Hg
✔✔To convert absolute pressure (psia) to gauge pressure (psig) _________ from the
absolute pressure. - ✔✔subtract 14.7
✔✔When the TLV-TWA (Threshold Limit Value - Time Weight Average) is exceeded,
ASHRAE Standard ________ requires that each machinery room activate an alarm and
a mechanical ventilation system. - ✔✔15-2013
✔✔___ refrigerant is classified as B1 - ✔✔R-123
✔✔____ is classified A1 - ✔✔R-1233zd
✔✔Refrigerants are ______ than air and can displace oxygen. - ✔✔Heavier
✔✔_____ and _____ _____ should be worn when working with liquid refrigerant for low-
pressure systems. - ✔✔Gloves : safety goggles
✔✔The discharge from a rupture disc or pressure relief valves should be piped _____ to
prevent venting into the machine room. - ✔✔Outdoors