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ARCtick Licence practice questions

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Question 1Refrigerant Handling Licence (RHL)

Under refrigerant handling regulations, what must a technician hold before purchasing or acquiring a controlled refrigerant?

  1. A general electrical contractor licence
  2. A plumbing registration certificate
  3. A current refrigerant handling licence or permit Correct answer.
  4. A valid driver's licence only

Explanation

Refrigerant handling rules require that anyone who acquires, buys, or takes delivery of a controlled refrigerant holds the appropriate refrigerant handling authorisation. The licence ties the individual to accountable handling, record keeping, and lawful recovery obligations. Other trade licences do not authorise refrigerant acquisition.

Question 2Refrigerant Handling Licence (RHL)

Which environmental problem is the primary reason refrigerants are regulated for emission control?

  1. Noise pollution in urban areas
  2. Light pollution from equipment
  3. Groundwater salinisation
  4. Ozone depletion and global warming potential Correct answer.

Explanation

Refrigerants are regulated because many deplete stratospheric ozone and most have significant global warming potential. Releasing them to the atmosphere contributes to both ozone layer damage and climate change. Emissions controls therefore target containment, recovery, and responsible disposal.

Question 3Refrigerant Handling Licence (RHL)

A technician finishes servicing a small split system and removes the refrigerant charge. What is the required handling of the recovered refrigerant?

  1. Vent it slowly outdoors to avoid pressure build-up
  2. Release it into the drain with water
  3. Recover it into a suitable container and send it for reclamation or destruction Correct answer.
  4. Dilute it with compressed air and discharge it

Explanation

Recovered refrigerant must be captured in a suitable, correctly labelled container and then reclaimed, recycled to standard, or destroyed by an authorised facility. Deliberate venting is prohibited because it releases ozone-depleting and high global warming substances. Dilution or draining does not make release lawful.

Question 4Refrigerant Handling Licence (RHL)

What is the main purpose of a recovery cylinder being clearly labelled with its contents?

  1. To record the cylinder's manufacturing date only
  2. To indicate the cylinder's paint colour code
  3. To prevent mixing incompatible refrigerants and enable safe handling Correct answer.
  4. To make the cylinder easier to sell at resale

Explanation

Labelling recovered refrigerant prevents different refrigerants from being blended into one container, which would make reclamation impossible and could create hazards. Clear identification also lets handlers select safe procedures and transport the cylinder lawfully. Colour alone is not a reliable identifier.

Question 5Refrigerant Handling Licence (RHL)

Which personal protective equipment is essential when handling refrigerant cylinders and charging systems?

  1. Steel-capped boots only
  2. A dust mask only
  3. Safety glasses or goggles and insulated gloves Correct answer.
  4. A high-visibility vest only

Explanation

Liquid refrigerant and escaping vapour can cause severe frostbite and eye injury, so eye protection and suitable gloves are essential. Refrigerant contact with skin or eyes requires immediate first aid and medical attention. Other items do not protect against cold burns.

Question 6Refrigerant Handling Licence (RHL)

Before commencing work on a refrigeration system, why must a technician verify the system's pressure has been safely released?

  1. To improve the system's cooling capacity
  2. To prevent injury and refrigerant release when opening the circuit Correct answer.
  3. To speed up the repair process
  4. To reduce the electricity bill during repair

Explanation

A pressurised circuit opened without depressurisation can violently release refrigerant, oil, and components, causing injury and environmental harm. Confirming isolation and recovery first is a basic safety step. Repair speed and efficiency are not the purpose of this check.

Question 7Refrigerant Handling Licence (RHL)

What does the term 'recovery' mean in refrigerant handling?

  1. Removing refrigerant from a system and storing it in an external container Correct answer.
  2. Adding refrigerant to top up a system charge
  3. Cleaning refrigerant to new-product specification
  4. Destroying refrigerant by burning it on site

Explanation

Recovery is the removal of refrigerant from a system into an external container without necessarily processing it. It is distinct from recycling, which cleans refrigerant for reuse, and from reclamation, which restores it to product specification. Topping up is charging, not recovery.

Question 8Refrigerant Handling Licence (RHL)

Why should refrigerant cylinders be secured upright during transport?

  1. To prevent valve damage and uncontrolled release Correct answer.
  2. To reduce fuel consumption of the vehicle
  3. To keep the cylinder looking tidy
  4. To comply with paint maintenance schedules

Explanation

An unsecured or lying cylinder can roll, strike objects, and damage the valve, leading to a rapid and dangerous release. Transport rules require cylinders to be restrained and protected so the valve stays intact. Appearance and fuel use are not the safety rationale.

Question 9Refrigerant Handling Licence (RHL)

A technician suspects a system contains a flammable refrigerant rather than the labelled refrigerant. What is the most appropriate action?

  1. Stop work, isolate the area, and identify the refrigerant before proceeding Correct answer.
  2. Proceed with hot work and monitor for odour
  3. Vent a small sample to check the smell
  4. Assume it is safe because the label says so

Explanation

Unknown or mislabelled refrigerant may be flammable or otherwise hazardous, so work must stop until the substance is identified with appropriate instruments. Hot work near an unidentified gas risks ignition. Odour is not a reliable identification method for refrigerants.

Question 10Refrigerant Handling Licence (RHL)

When evacuating a system before charging, why is a deep vacuum used rather than simply purging with refrigerant?

  1. To cool the compressor before start-up
  2. To remove moisture and non-condensable gases from the circuit Correct answer.
  3. To test the electrical insulation of the compressor
  4. To increase the system's refrigerant charge

Explanation

A deep vacuum lowers the boiling point of water so moisture in the circuit evaporates and is drawn out, and it removes non-condensables such as air. Purging with refrigerant is prohibited because it releases refrigerant to atmosphere. Vacuum work does not test insulation or set charge levels.

Question 11Refrigerant Handling Licence (RHL)

Which practice best prevents cross-contamination when recovering refrigerant from different systems?

  1. Use one cylinder for all refrigerants to save space
  2. Use a dedicated recovery cylinder and separate hoses for each refrigerant type Correct answer.
  3. Flush the recovery unit with air between jobs
  4. Rely on the system labels and skip checking the refrigerant

Explanation

Mixing refrigerants in a single cylinder makes reclamation impossible and can create unsafe blends. Dedicated cylinders and hoses prevent cross-contamination and preserve the recovered refrigerant's value. Air flushing introduces moisture and non-condensables and is not acceptable.

Question 12Refrigerant Handling Licence (RHL)

What must be done with a recovered refrigerant that cannot be reclaimed to a usable standard?

  1. Discharge it through the recovery unit's vent
  2. Blend it with new refrigerant and resell it
  3. Store it indefinitely in an unlabelled drum
  4. Send it to an authorised facility for destruction Correct answer.

Explanation

Refrigerant that cannot be reclaimed must be destroyed by an authorised facility so emissions are controlled. Indefinite unlabelled storage creates hazards and regulatory breaches. Blending it with new product or venting it is unlawful.

Question 13Refrigerant Handling Licence (RHL)

A technician notices oil staining around a flare connection on a recently installed system. What does this most likely indicate?

  1. A normal manufacturing finish
  2. An electrical fault in the compressor
  3. A refrigerant leak at the joint Correct answer.
  4. A blocked condensate drain

Explanation

Refrigerant carries oil through the circuit, so oil staining at a joint often signals a small leak that has been escaping with the oil. The joint should be leak-tested and repaired. Oil staining is not a normal finish and is unrelated to electrical faults or drains.

Question 14Refrigerant Handling Licence (RHL)

Why is nitrogen used for pressure testing a refrigeration circuit rather than oxygen?

  1. Nitrogen improves the cooling performance
  2. Nitrogen changes colour when a leak occurs
  3. Nitrogen is inert and does not support combustion or react with oil Correct answer.
  4. Nitrogen is cheaper than all other gases

Explanation

Nitrogen is inert and dry, so it can pressurise a circuit without reacting with oil or supporting combustion. Oxygen under pressure can react violently with oil and is never acceptable for this test. Cost and cooling performance are not the governing reasons.

Question 15Refrigerant Handling Licence (RHL)

What information should a refrigerant usage record capture for each recovered charge?

  1. Refrigerant type, quantity, date, and system or source Correct answer.
  2. Only the cylinder's tare weight
  3. Only the technician's signature
  4. Only the customer's address

Explanation

Accurate records must identify the refrigerant type, the quantity recovered, the date, and the equipment or source involved. These details support tracking, auditing, and lawful disposal. A signature, address, or tare weight alone is insufficient.

Question 16Refrigerant Handling Licence (RHL)

A recovery cylinder is filled to 90 percent of its capacity with liquid refrigerant. What risk does this present?

  1. The cylinder will lose its paint
  2. The refrigerant will become flammable
  3. Hydraulic pressure rise from liquid expansion can rupture the cylinder Correct answer.
  4. The refrigerant will change into a different chemical

Explanation

Cylinders must never be filled with liquid to the brim because warming causes liquid expansion and a rapid hydraulic pressure rise that can rupture the container. Recovery cylinders are filled to a safe percentage by weight, not volume. Flammability and paint are not the issue.

Question 17Refrigerant Handling Licence (RHL)

Why should a technician never use a refrigerant cylinder as a platform or support?

  1. It voids the refrigerant's warranty only
  2. It can damage the valve and cause an uncontrolled release Correct answer.
  3. It causes the refrigerant to freeze
  4. It makes the cylinder heavier

Explanation

Cylinders are pressure vessels, and standing on them or using them as supports can bend or shear the valve, producing a dangerous release. Physical damage can also weaken the cylinder wall. The concern is safety, not warranty or weight.

Question 18Refrigerant Handling Licence (RHL)

When brazing refrigerant pipework, what is the purpose of flowing dry nitrogen through the pipe?

  1. To detect the presence of moisture
  2. To add pressure to the system charge
  3. To cool the pipe so it does not melt
  4. To prevent oxidation and scale forming inside the pipe Correct answer.

Explanation

A slow nitrogen purge displaces air so the hot interior does not oxidise and form scale, which could later block strainers or damage the compressor. The nitrogen is not a charge and is not used to cool the joint. Moisture detection requires separate instruments.

Question 19Refrigerant Handling Licence (RHL)

A system uses a refrigerant with a high global warming potential. Which maintenance approach best reduces environmental impact?

  1. Increase the charge to reduce running time
  2. Find and repair leaks promptly and keep charges contained Correct answer.
  3. Top up the charge regularly without leak testing
  4. Replace the refrigerant with an unapproved substitute

Explanation

Prompt leak detection and repair keeps the high-GWP charge inside the system instead of escaping to the atmosphere. Repeated top-ups without leak testing hide ongoing emissions. Oversizing the charge or using unapproved substitutes creates safety and compliance problems.

Question 20Refrigerant Handling Licence (RHL)

What is the correct response if liquid refrigerant contacts a technician's skin?

  1. Rub the area vigorously to restore warmth
  2. Apply direct heat from a torch
  3. Continue working and ignore the injury
  4. Flush with lukewarm water, remove contaminated clothing, and seek medical help Correct answer.

Explanation

Liquid refrigerant causes cold burns, so the area should be flushed with lukewarm water and contaminated clothing removed carefully to avoid further freezing. Medical attention is required because tissue damage may be deeper than it appears. Rubbing, direct heat, or ignoring the injury worsens harm.

Question 21Refrigerant Handling Licence (RHL)

An older system contains a chlorofluorocarbon refrigerant. Why is special care required when servicing it?

  1. It can be disposed of in general waste
  2. It is harmless and can be released freely
  3. It has high ozone-depleting potential and must be recovered, not vented Correct answer.
  4. It is always flammable and must be burnt

Explanation

Chlorofluorocarbons have high ozone-depleting potential, so they must be recovered and sent for reclamation or destruction rather than vented. Release is prohibited regardless of the system's age. They are not generally flammable, and they are not general waste.

Question 22Refrigerant Handling Licence (RHL)

A technician plans to retrofit a system from an ozone-depleting refrigerant to a newer blend. Which step is most important before charging the new refrigerant?

  1. Confirm compatibility of the lubricant, seals, and components with the new refrigerant Correct answer.
  2. Increase the compressor size without assessment
  3. Simply add the new refrigerant on top of the old charge
  4. Vent the old charge to save recovery time

Explanation

Retrofits require checking that the lubricant, elastomers, and system components are compatible with the replacement refrigerant and that the old charge is fully recovered. Mixing old and new refrigerants can cause performance and safety problems. Venting the old charge is prohibited.

Question 23Refrigerant Handling Licence (RHL)

Why is it important to weigh refrigerant into a system rather than charge by pressure alone?

  1. Weight charging eliminates the need for leak testing
  2. Pressure gauges are always faulty
  3. Weight gives an accurate charge and avoids overcharge or undercharge Correct answer.
  4. Pressure charging is faster and always more accurate

Explanation

Weighing the charge ensures the exact mass specified by the manufacturer, whereas pressure alone varies with temperature and can mislead. Incorrect charge mass reduces performance and can damage the compressor. Weight charging does not replace leak testing.

Question 24Refrigerant Handling Licence (RHL)

A recovery machine is rated for a particular refrigerant but is used with an unfamiliar flammable refrigerant. What is the key concern?

  1. The cylinder will become lighter than its tare
  2. The machine and area may not be rated for flammable gas, creating an ignition risk Correct answer.
  3. The refrigerant will lose its colour
  4. The machine will recover the gas too quickly

Explanation

Equipment used with flammable refrigerants must be rated for that service, and the work area must avoid ignition sources. Using a non-rated recovery machine can create an explosion hazard. Recovery speed, colour, and cylinder weight are not the governing safety issue.

Question 25Refrigerant Handling Licence (RHL)

Which combination of records best demonstrates compliance after recovering refrigerant from a decommissioned system?

  1. The cylinder colour and the vehicle registration
  2. The customer's phone number and the invoice total
  3. The equipment's model number and the weather conditions
  4. Refrigerant type, mass recovered, date, destination, and technician authorisation Correct answer.

Explanation

Compliance records must trace the refrigerant from recovery to its destination, showing what was recovered, how much, when, and by whom. This chain supports audits and confirms lawful disposal or reclamation. Contact details, model numbers, or colour codes do not establish traceability.

Question 26Refrigerant Handling Licence (RHL)

Which property of a refrigerant determines the colour code that may be applied to its cylinder?

  1. The refrigerant's safety classification group
  2. The refrigerant's chemical family as listed in the relevant standard Correct answer.
  3. The refrigerant's global warming potential value
  4. The refrigerant's boiling point at atmospheric pressure

Explanation

Cylinder colour codes are assigned according to the chemical family of the refrigerant under the applicable standard, so the same colour family may be shared by several refrigerants. Colour is only a secondary aid and the cylinder label must always be checked. Boiling point, GWP and safety group do not determine the colour code.

Question 27Refrigerant Handling Licence (RHL)

Which document must accompany a refrigerant cylinder so that the handler knows its contents and hazards?

  1. A calibration certificate for the cylinder valve
  2. A delivery docket signed by the purchaser
  3. A safety data sheet for the refrigerant Correct answer.
  4. A warranty card from the cylinder manufacturer

Explanation

A safety data sheet provides the identity, hazard information, first aid measures and handling precautions for the refrigerant. It must be available to anyone storing or using the substance. Dockets, calibration certificates and warranties do not describe chemical hazards.

Question 28Refrigerant Handling Licence (RHL)

What is the main purpose of wearing suitable gloves when handling refrigerant cylinders and connecting hoses?

  1. To reduce static electricity generated during transfers
  2. To protect the skin from frostbite caused by rapid refrigerant evaporation Correct answer.
  3. To prevent the transfer of refrigerant vapour into the bloodstream
  4. To improve grip on oily brass fittings

Explanation

Liquid refrigerant boils rapidly at atmospheric pressure and can freeze skin on contact, so gloves protect against cold burns. Refrigerant vapour is not absorbed through intact skin in a way that gloves would prevent. Grip, static and oil resistance are secondary considerations.

Question 29Refrigerant Handling Licence (RHL)

Why must a refrigerant cylinder never be heated with an open flame to raise its pressure?

  1. The cylinder may float if placed in water later
  2. The valve seal may become too soft to open
  3. The paint on the cylinder may discolour
  4. The refrigerant may decompose into corrosive compounds and the cylinder may rupture Correct answer.

Explanation

Direct flame heating can decompose the refrigerant into toxic or corrosive products and can overpressure the cylinder until it ruptures. Only controlled warm water or approved warming equipment should be used. Cosmetic and handling concerns are not the safety reason.

Question 30Refrigerant Handling Licence (RHL)

What does the term 'reclaim' mean when applied to used refrigerant?

  1. Reprocessing the refrigerant to new product specification, verified by analysis Correct answer.
  2. Reprocessing the refrigerant on site to remove moisture and acid only
  3. Storing the refrigerant in any suitable container until disposal
  4. Burning the refrigerant to recover its energy content

Explanation

Reclaiming is reprocessing used refrigerant to meet the specification of new product, which requires chemical analysis to verify purity. On-site filtering is cleaning rather than reclaiming, and storage or destruction are separate activities. Reclaiming restores the refrigerant to a usable, specified standard.

Question 31Refrigerant Handling Licence (RHL)

Which piece of information must appear on a label attached to a recovered refrigerant container?

  1. The name of the equipment owner
  2. The ambient temperature at the time of recovery
  3. The identity of the refrigerant contained Correct answer.
  4. The date the recovery machine was last serviced

Explanation

Every container of recovered refrigerant must be labelled with the refrigerant identity so that it is not mixed or misused. Additional details such as quantity and source may be recorded, but identity is essential. Service dates and ambient conditions are not labelling requirements.

Question 32Refrigerant Handling Licence (RHL)

What is the purpose of a Schrader valve depressor on a charging hose?

  1. To filter moisture from the refrigerant
  2. To measure the pressure inside the hose
  3. To prevent the hose from being over-tightened
  4. To open the service valve core so refrigerant can flow Correct answer.

Explanation

A depressor pushes the valve core open so that refrigerant can pass through the service port. Without it, the hose may appear connected but no flow occurs. It does not measure pressure, filter refrigerant or limit tightening torque.

Question 33Refrigerant Handling Licence (RHL)

Which refrigerant is commonly used in domestic refrigerators and small commercial cabinets and has a safety group classification of A1?

  1. R-134a Correct answer.
  2. R-717 (ammonia)
  3. R-600a (isobutane)
  4. R-744 (carbon dioxide)

Explanation

R-134a is a non-flammable, low-toxicity refrigerant widely used in domestic and small commercial refrigeration and is classified A1. Ammonia is toxic and has a different classification, isobutane is flammable, and carbon dioxide operates at very high pressures with its own hazards.

Question 34Refrigerant Handling Licence (RHL)

A technician must recover refrigerant from a system that uses a zeotropic blend. Which practice best preserves the correct composition of the recovered charge?

  1. Recover the charge quickly as a vapour only
  2. Recover the charge as a liquid where possible and avoid deliberate vapour-only withdrawal Correct answer.
  3. Recover only the liquid fraction and leave the vapour in the system
  4. Vent a portion of the charge to atmosphere before recovery

Explanation

Zeotropic blends change composition when vapour is withdrawn, because components boil at different rates. Recovering the charge as liquid, or using recovery methods that remove liquid and vapour together in the correct proportion, preserves the blend composition. Venting or vapour-only recovery would alter the mixture.

Question 35Refrigerant Handling Licence (RHL)

Why should a vacuum pump be fitted with a vacuum gauge at the pump inlet rather than relying on the manifold gauge set?

  1. Vacuum pumps only operate correctly when a gauge is connected to the inlet
  2. The manifold gauge set is calibrated for liquid refrigerant only
  3. Hoses and manifold ports can prevent the system reaching a deep vacuum, so the reading must be taken close to the system Correct answer.
  4. Manifold gauges cannot display positive pressure

Explanation

Manifold gauge sets and their hoses have significant pressure drop at deep vacuum, so a gauge at the pump inlet may read a much lower pressure than the system actually reaches. A gauge connected close to the system, or an electronic vacuum gauge, gives a true indication of system evacuation.

Question 36Refrigerant Handling Licence (RHL)

A technician is about to braze a joint on a system containing a flammable refrigerant. Which action is most important before applying heat?

  1. Increase the nitrogen flow to dilute any remaining refrigerant
  2. Open the system to atmosphere and begin brazing immediately
  3. Recover the refrigerant and confirm the system is free of flammable gas Correct answer.
  4. Purge the system with the same refrigerant to displace air

Explanation

Flammable refrigerant remaining in the pipework can ignite when brazed, so the charge must be recovered and the system confirmed free of flammable gas before heat is applied. Purging with refrigerant adds more fuel, and simply opening the system does not remove residual gas.

Question 37Refrigerant Handling Licence (RHL)

What is the purpose of a liquid indicator (moisture sight glass) in a refrigerant liquid line?

  1. To give an indication of moisture content and liquid condition in the line Correct answer.
  2. To measure the refrigerant's global warming potential
  3. To regulate the flow of refrigerant to the evaporator
  4. To confirm that the compressor is running

Explanation

A sight glass with a moisture indicator shows whether the liquid line contains bubbles and whether moisture levels are within acceptable limits. It does not control flow or confirm compressor operation. GWP is a fixed property of the refrigerant.

Question 38Refrigerant Handling Licence (RHL)

Which condition indicates that a recovery cylinder is unsuitable for further use?

  1. The cylinder was previously used for a different refrigerant
  2. The cylinder has been repainted in the correct colour
  3. The cylinder has a current pressure test date and intact valve
  4. The cylinder shows dents, deep corrosion or a damaged valve Correct answer.

Explanation

Cylinders with dents, significant corrosion or damaged valves may have reduced strength and must be removed from service. A valid test date, correct colour and previous contents do not by themselves make a cylinder unsuitable. Damaged cylinders should be returned to the supplier rather than used.

Question 39Refrigerant Handling Licence (RHL)

Why should a technician avoid using a recovery cylinder that has no valid pressure test date?

  1. The refrigerant inside will have degraded
  2. The recovery machine will not connect to it
  3. The cylinder will not fit on the weighing scale
  4. The cylinder may not meet the required pressure rating and could fail during use Correct answer.

Explanation

Pressure test dates confirm that the cylinder has been inspected and is fit for its rated pressure. Using an out-of-date cylinder means its integrity is unverified, creating a risk of rupture. Refrigerant quality and equipment fit are unrelated to the test date.

Question 40Refrigerant Handling Licence (RHL)

A technician is recovering refrigerant from a system and notices the recovery cylinder becoming cold and frosted. What is the most likely explanation?

  1. The recovery machine is running too slowly
  2. The cylinder is overfilled with liquid
  3. Refrigerant is boiling in the cylinder as pressure is released, cooling the metal Correct answer.
  4. The cylinder valve is leaking refrigerant into the room

Explanation

As refrigerant vapour is drawn from the cylinder, liquid refrigerant boils and absorbs heat, cooling the cylinder wall and causing frost. This is normal behaviour during recovery. Overfilling is indicated by weight, not by frost alone, and a leak would show as a pressure loss rather than cooling.

Question 41Refrigerant Handling Licence (RHL)

Which action best reduces the risk of releasing refrigerant when disconnecting hoses after a transfer?

  1. Loosen the hose slightly and wait until it stops hissing
  2. Leave the hose connected permanently to avoid disconnection
  3. Close the valves and recover or draw off the refrigerant trapped in the hoses before disconnection Correct answer.
  4. Disconnect the hose quickly to minimise the escape time

Explanation

Refrigerant trapped between valves in hoses will escape when the connection is opened. Closing valves and recovering or drawing off the trapped charge before disconnection minimises emissions. Quick disconnection or loosening the fitting simply vents the trapped refrigerant.

Question 42Refrigerant Handling Licence (RHL)

What is the primary reason for recording the weight of refrigerant charged into a system?

  1. To calculate the compressor's running current
  2. To provide a verifiable record of the quantity used and enable leak detection by future comparison Correct answer.
  3. To satisfy the equipment manufacturer's warranty terms only
  4. To determine the correct colour code for the cylinder

Explanation

Recording charged weight gives a documented quantity that supports leak checking and future comparisons, and it is required for refrigerant accounting. It does not determine electrical current or cylinder colour. Warranty compliance is not the primary environmental reason.

Question 43Refrigerant Handling Licence (RHL)

Which hazard is created when air is left in a refrigeration system before charging?

  1. The expansion valve will freeze closed
  2. The refrigerant becomes less efficient at absorbing heat
  3. Non-condensable gases raise discharge pressure and temperature and can degrade lubricant Correct answer.
  4. The system's electrical controls will not operate

Explanation

Air is non-condensable and accumulates in the condenser, raising discharge pressure and temperature, which increases compressor load and can degrade lubricant. It does not improve or reduce the refrigerant's heat absorption in a useful way, and it does not affect electrical controls directly.

Question 44Refrigerant Handling Licence (RHL)

A technician is servicing a system that uses a refrigerant with a safety group classification of A2L. Which precaution is most appropriate?

  1. Eliminate ignition sources and follow the manufacturer's flammable refrigerant procedures Correct answer.
  2. Use only open flame leak detection to find leaks quickly
  3. Treat the refrigerant as non-flammable and ignore ignition sources
  4. Increase the charge size to improve cooling performance

Explanation

A2L refrigerants have low flammability, so ignition sources must be controlled and the manufacturer's procedures for flammable refrigerants must be followed. They cannot be treated as non-flammable, and increasing charge or using open flame leak detection would create additional hazards.

Question 45Refrigerant Handling Licence (RHL)

Why is it important to use a recovery machine with a compressor rated for the specific refrigerant being recovered?

  1. The recovery cylinder will not accept a different refrigerant
  2. The machine will otherwise run at the wrong voltage
  3. The refrigerant will change colour during recovery
  4. The machine's lubricant and seals may be incompatible with unfamiliar refrigerants, causing failure or contamination Correct answer.

Explanation

Recovery machine compressors use lubricants and seal materials selected for particular refrigerant families. Using an incompatible refrigerant can degrade seals, cause mechanical failure and contaminate the recovered charge. Voltage, cylinder acceptance and colour are not the underlying issue.

Question 46Refrigerant Handling Licence (RHL)

Which practice best protects a technician from oxygen deficiency when working in a plant room where large refrigerant leaks are possible?

  1. Wear a dust mask and proceed with the task
  2. Open a window and work alone to reduce exposure time
  3. Rely on the refrigerant's distinctive smell to warn of leaks
  4. Use a calibrated gas detector and follow confined space entry procedures where applicable Correct answer.

Explanation

Many refrigerants are heavier than air and can displace oxygen in low-lying areas, and some have little or no odour at hazardous concentrations. A calibrated gas detector and formal entry procedures provide reliable warning and control. Smell and dust masks are not reliable protection.

Question 47Refrigerant Handling Licence (RHL)

A technician finds that a system's refrigerant charge has been topped up repeatedly over several months without any leak investigation. What is the most significant consequence?

  1. The system's electrical consumption will fall
  2. The compressor will run at a lower discharge temperature
  3. The system's cooling capacity will gradually increase
  4. Refrigerant is being emitted to the atmosphere and the underlying leak remains unresolved Correct answer.

Explanation

Repeated topping up without leak repair means refrigerant is escaping to the atmosphere, which is both an environmental harm and an unresolved fault. The leak will continue and may worsen. Topping up does not increase capacity or reduce energy use.

Question 48Refrigerant Handling Licence (RHL)

Which statement correctly describes the relationship between a refrigerant's ozone depletion potential and its chlorine content?

  1. ODP increases as the refrigerant's global warming potential decreases
  2. ODP depends mainly on the presence of chlorine or bromine atoms that can reach the stratosphere Correct answer.
  3. ODP is zero for all refrigerants containing fluorine
  4. ODP is determined solely by the refrigerant's boiling point

Explanation

Ozone depletion is driven by chlorine and bromine atoms released in the stratosphere, so refrigerants containing these halogens can have a non-zero ODP. Boiling point and GWP are separate properties, and fluorine-containing refrigerants such as HFCs have zero ODP because fluorine does not catalytically destroy ozone in the same way.

Question 49Refrigerant Handling Licence (RHL)

A technician must dispose of a small quantity of recovered refrigerant that is contaminated with acid and moisture and cannot be reclaimed. Which route is correct?

  1. Vent it slowly outdoors in small amounts
  2. Pour it into an approved drain with plenty of water
  3. Store it indefinitely in an unlabelled container
  4. Return it to a licensed reclaiming or destruction facility Correct answer.

Explanation

Refrigerant that cannot be reclaimed must be sent to a licensed facility for reclamation or destruction, with the transfer documented. Venting, draining or indefinite unlabelled storage are all prohibited because they release refrigerant or create uncontrolled hazards.

Question 50Refrigerant Handling Licence (RHL)

Why does a blend containing a high proportion of a low-boiling component require particular care when charging as a vapour?

  1. The low-boiling component vaporises preferentially, so the cylinder composition changes as vapour is drawn Correct answer.
  2. The blend becomes non-flammable when drawn as vapour
  3. The cylinder pressure falls to zero immediately
  4. The low-boiling component solidifies at room temperature

Explanation

In a zeotropic blend the components have different boiling points, so drawing vapour preferentially removes the more volatile component and leaves a liquid richer in the less volatile one. Charging from the cylinder in this way can therefore deliver the wrong composition to the system. Liquid charging, or full cylinder use, avoids the problem.