Type II A2L systems & safety: EPA 608 Practice Questions

Question 1

Many ducted A2L systems include a refrigerant detection sensor. What does the system typically do when the sensor detects a leak?

Accepted Answer

Turns on the indoor blower to dilute the refrigerant

Answer

Opens the outdoor service valves to pump the charge into the condenser

Answer

Shuts off the blower to contain the refrigerant

Answer

Sends a signal that releases nitrogen into the duct system to smother any flame

Question 2

A technician's recovery machine was made in 2015 and is certified only for non-flammable refrigerants. May it be used on an R-32 system?

Accepted Answer

No; use a machine rated for A2L refrigerants

Answer

Yes, since R-32 is one of the two components of R-410A

Answer

Yes, as long as the work area is well ventilated

Answer

Yes, if the machine's fan is unplugged so it cannot spark while running

Question 3

Before starting service on an R-454B system in a small mechanical closet, what should the technician do first?

Accepted Answer

Check for ignition sources and ventilate the area

Answer

Close the door to keep refrigerant in

Answer

Light a match to check for gas

Answer

Turn off the lights so the switch cannot spark, then work with a flashlight that has a metal case

Question 4

For A2L split systems, what limits the maximum refrigerant charge allowed for a given installation?

Accepted Answer

The size of the room or space served

Answer

The color and size of the refrigerant cylinder

Answer

The length of the warranty

Answer

The outdoor temperature on the day the system is charged

Question 5

Which leak detector is appropriate for an R-32 system?

Accepted Answer

An electronic detector rated for A2L refrigerants

Answer

Any detector built before 2000, since R-32 has been in use since the 1990s

Answer

A propane torch held near the joints

Answer

A halide torch

Question 6

An R-410A system is low on charge, and only R-454B is on the truck. What should the technician do?

Accepted Answer

Not add R-454B; use R-410A as the system is designed

Answer

Add R-454B and attach a label noting the mix, so the next technician knows

Answer

Add R-454B up to half the charge

Answer

Add R-454B, since both refrigerants contain R-32 and similar oil

Question 7

R-32 is a single-component refrigerant. How does that affect how it may be charged?

Accepted Answer

It can be charged as vapor or liquid without changing composition

Answer

It must always be charged as liquid

Answer

It must be charged only through the liquid line while the system is running

Answer

It must always be charged as vapor

Question 8

R-454B has only a small temperature glide. How should it still be removed from the cylinder for charging?

Accepted Answer

As liquid

Answer

As vapor

Answer

Either way, since it is near-azeotropic

Answer

As vapor at first, then as liquid once the cylinder is half empty

Question 9

How are A2L refrigerant cylinder valves usually threaded, compared with A1 cylinders?

Accepted Answer

Left-hand threads, needing an adapter

Answer

No threads; they use push-on fittings

Answer

Metric threads that match vehicle service ports, so they fit automotive gauges

Answer

Right-hand threads, the same as A1

Question 10

A large system in a machinery room uses an A2L refrigerant. What does ASHRAE 15 generally require in that room?

Accepted Answer

Refrigerant detectors that alarm and start ventilation

Answer

A sign stating the refrigerant type

Answer

A window that can be opened

Answer

Only a fire extinguisher

Question 11

After a compressor burnout, what test shows whether the oil is contaminated with acid?

Accepted Answer

An acid test kit on an oil sample

Answer

A megohmmeter test of the motor windings

Answer

Smelling the refrigerant at the gauge port, which is the method manufacturers recommend

Answer

A micron gauge reading taken during evacuation

Question 12

If an A2L refrigerant does ignite, what hazard does the fire create besides heat?

Accepted Answer

Toxic hydrogen fluoride gas

Answer

Pure oxygen released from the refrigerant

Answer

Harmless water vapor only

Answer

Carbon monoxide only, the same as a gas furnace

Question 13

The nameplate of a rooftop unit lists a low-side test pressure. Why does that matter during a nitrogen pressure test?

Accepted Answer

The low side must not exceed that pressure

Answer

It sets the relief valve on the recovery machine

Answer

It is the pressure to charge refrigerant to

Answer

It is the minimum pressure needed to find leaks with an electronic detector

Question 14

Refrigerant recovered after a severe compressor burnout should be handled how?

Accepted Answer

Kept in a separate cylinder and sent for reclamation

Answer

Charged into another customer's system after one filter pass

Answer

Vented, because it is contaminated

Answer

Filtered once through the recovery machine and then sold to a supply house as used refrigerant

Question 15

Why must replacement parts on an A2L system, such as contactors or fan motors near the refrigerant circuit, match the manufacturer's specifications?

Accepted Answer

Some are chosen so they cannot ignite leaked refrigerant

Answer

Only original parts fit A2L wiring

Answer

Non-original parts change the refrigerant's safety class from A2L to A3

Answer

Generic parts would void the technician's EPA certification

Type II A2L systems & safety: EPA 608 Practice Questions

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