ESCO A2L - ESCO A2L Refrigerant Servicing and Charging Procedures Questions and Answers

Question 1

A technician is setting up to recover R-32 from a residential split system.
In addition to ensuring the recovery machine is rated for A2L refrigerants, what is a critical safety step to prevent a static discharge from becoming an ignition source?

Accepted Answer

Ensure the recovery machine and system are electrically bonded and grounded.

Answer

Chill the recovery cylinder in an ice bath.

Answer

Operate the recovery machine at the lowest possible speed.

Answer

Purge the recovery hoses with nitrogen before connecting them.

Question 2

When charging a system with a zeotropic A2L refrigerant blend, such as R-454B, why must it be removed from the cylinder as a liquid?

Accepted Answer

To ensure the correct refrigerant composition and temperature glide are maintained in the system.

Answer

To prevent the cylinder pressure from dropping too quickly.

Answer

To cool the service hoses and prevent them from bursting.

Answer

Because A2L refrigerants are too dense to be charged as a vapor.

Question 3

Which of the following is a mandatory first step before opening any part of a charged A2L refrigerant system for service?

Accepted Answer

Ensure the work area is well-ventilated to keep concentrations below the LFL.

Answer

Pre-cool all service tools to prevent refrigerant from flashing.

Answer

Notify the local fire department of the service activity.

Answer

Verify the system's factory warranty is still active.

Question 4

After repairing a leak in an R-454B system and before pulling a vacuum, a technician should perform a nitrogen purge. What is the primary safety purpose of this step in an A2L context?

Accepted Answer

To displace any remaining refrigerant vapor and oxygen, creating a non-flammable mixture.

Answer

To pressurize the system for a final strength test.

Answer

To clean any debris from the newly brazed joint.

Answer

To cool the compressor before restarting the system.

Question 5

When adding the initial or full charge of an A2L refrigerant to an evacuated system, what is the best practice for ensuring accuracy and safety?

Accepted Answer

Use a charging scale to weigh in the exact amount of liquid refrigerant specified by the manufacturer.

Answer

Charge by superheat or subcooling readings immediately after starting the system.

Answer

Add refrigerant vapor until the low-side and high-side pressures stabilize.

Answer

Add refrigerant until the liquid line sight glass is completely clear of bubbles.

Question 6

Which of the following is a key safety consideration regarding the exhaust from a vacuum pump used to evacuate a system that previously contained an A2L refrigerant?

Accepted Answer

The exhaust may contain refrigerant vapor and should be vented to a well-ventilated area away from ignition sources.

Answer

The exhaust should be filtered through a universal desiccant core.

Answer

The exhaust must be captured in a separate, empty recovery cylinder.

Answer

The exhaust temperature must be monitored to ensure it does not exceed 100°F (38°C).

A technician is setting up to recover R-32 from a residential split system.In addition to ensuring the recovery machine is rated for A2L refrigerants, what is a critical safety step to prevent a static discharge from becoming an ignition source?

A technician is setting up to recover R-32 from a residential split system.
In addition to ensuring the recovery machine is rated for A2L refrigerants, what is a critical safety step to prevent a static discharge from becoming an ignition source?