System Installation and Brazing Flashcards
7 cards from real 313D practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 System Installation and Brazing flashcards as text
When connecting the refrigerant line set to a new condenser unit, the technician notices the factory-installed service valves are in the fully closed (back-seated) position. This means:
Answer: The refrigerant charge is retained inside the unit and the Schrader port is open to the line side
When a service valve is back-seated (fully counterclockwise), the refrigerant charge is sealed inside the unit and the gauge port is open to the system side for servicing.
A kinked refrigerant line during installation should be:
Answer: Cut out and replaced with a new section of properly routed tubing
A kinked tube has a weakened wall that can fail under pressure, so the kinked section must be cut out and replaced with new tubing.
The primary purpose of installing a filter-drier in the liquid line of a new residential AC system is to:
Answer: Remove moisture and contaminants that could damage the system
A filter-drier absorbs moisture and traps particulates, protecting the metering device and compressor from contamination and acid formation.
When making a brazed joint, the correct way to apply the brazing rod is:
Answer: Hold the rod at the joint and let the heat of the base metal melt the filler
The base metal's heat should melt the brazing rod at the joint, allowing capillary action to draw the filler into the gap for full penetration.
An installer finds the line set must run 80 feet between the condenser and air handler, exceeding the standard charge. According to manufacturers, the technician should:
Answer: Add refrigerant per the manufacturer's specified charge adjustment for the extra line length
Manufacturers provide a charge correction formula (typically oz per additional foot of liquid line) that must be followed to maintain proper system performance.
When installing refrigerant line sets in a chase or conduit alongside electrical wiring, the installer must ensure:
Answer: Refrigerant lines are separated from electrical conductors or use NEC-compliant separation methods
The NEC and local codes require separation between refrigerant lines and electrical conductors to prevent insulation damage and potential shock or fire hazards.
After charging a newly installed residential split system, the technician verifies proper operation by checking that:
Answer: Superheat and subcooling readings match the manufacturer's target values for the conditions
Verifying superheat and subcooling against manufacturer targets confirms the refrigerant charge is correct and the system is operating within design parameters.