Heat pumps that use R-410A should be leak checked with
Heat pumps that have been retrofitted from R-22 to R-407C should be leak checked with
To change the compressor on a system containing R-410A, you must isolate the compressor and then
The method to charge a system that has a normal charge of 80 pounds is to charge with
After installation of a field-piped R-410A split heat pump, the unit should first be
Pressure relief valves must not be
When charging an R-12 refrigeration system that uses a water-cooled condenser, you must first charge with vapor to a pressure of at least _____ before switching to liquid charging.
Your recovery/recycling machine has R-22 refrigerant in it. You now have to recover refrigerant from a unit with R-410A. What must be done before your recovery unit can be used to recover R-410A?
After reaching the required recovery vacuum on a system you must
In a refrigeration system, the component directly following the evaporator is the
A reciprocating compressor should not be energized while
R-410A requires a high-pressure manifold gauge and hose set. They must have a
The refrigerant pressure inside an R-410A unit which is at room temperature (72F) and not operating is
Every air conditioning or refrigeration system should be protected by a
To change the compressor on a system containing 40 pounds of R-500 using a recycling machine that was manufactured AFTER November 15 1993, you must isolate the compressor then
When inspecting a system for leaks, you should look for
When a new system has been assembled, the first thing to do is
R-410A is different from other ASHRAE 400 series non-azeotropic blends because
Manifold gauge set hoses should have self-sealing connectors or hand valves to
When using recovery or recycling equipment that was manufactured AFTER November 15 1993, you must evacuate a system containing MORE than 200 pounds of CFC-12 to _______ before making a major repair.
With an air-cooled condenser on the roof of a building and the evaporator on the first floor, recovery should first occur
Never use oxygen or compressed air to leak check equipment because R-410A can
Dry nitrogen should be used to break the first vacuum when dehydrating by the double evacuation method. However, it
A recovery machine that uses a hermetic compressor will overheat when drawing a deep vacuum because
The proper charging method for blended (non-azeotropic) refrigerants (400 series) is to remove the charge from the cylinder as a
