What is the best way to study for the Red Seal Refrigeration & AC Mechanic (313A) exam?

Consistent daily practice beats last-minute cramming. Red Seal Pass uses the Ebbinghaus spaced-repetition method to schedule automated review of your wrong answers at 1, 3, and 7-day intervals, paired with real-time AI Journeyperson explanations.

What does a subscription cost and how does the Free-Until-You-Pass Guarantee work?

We offer a 7-Day Pass ($9.99 CAD one-time), a Monthly Pass ($29.99 CAD/month), and a 3-Month Pass ($69.99 CAD one-time) backed by our Free-Until-You-Pass Guarantee. If you purchase the 3-Month Pass, complete at least 70% of the course questions, write your official exam within 6 months, and do not pass, we extend your access free in 3-month intervals until you pass.

313A Refrigeration & AC Practice Test: Free Questions

Q: Can I sample practice questions before subscribing?

Yes. You can take the interactive 10-question readiness quiz directly on this page with no sign-up required, or download our free 30-question printable sample mock exam PDF with step-by-step answer explanations. A subscription unlocks all 1250 Refrigeration & AC Mechanic (313A) questions, spaced-repetition review, and AI tutoring.

Preparing for the Red Seal Refrigeration & AC Mechanic (313A) exam

The Red Seal (Interprovincial) Refrigeration & AC Mechanic (313A) exam tests everything a working mechanic needs: refrigeration cycles, heat pumps, psychrometrics, compressors and evaporators, controls, and CSA B52 safety code. Trying to memorize a thousand questions the night before rarely sticks. Research on the Ebbinghaus forgetting curve shows that spaced review holds knowledge better than cramming.

Red Seal Pass gives you a smarter path: a focused set of new questions each day, automatic review of the ones you miss, and clear explanations so you learn why, not just what.

🛡️ Free-Until-You-Pass Guarantee — buy the 3-Month Pass ($69.99 CAD), and if you don't pass we extend your access free until you do.

📥 Free Printable 30-Question Refrigeration & AC Mechanic (313A) Mock Exam PDF

Download our 30-question sample mock exam PDF with complete step-by-step answer keys and a blueprint breakdown.

🎧 Listen: the 30 Refrigeration & AC Mechanic (313A) Questions, Read Aloud

The same 30 questions as the free PDF, each read aloud with a 5-second pause before the answer and explanation.

Red Seal Refrigeration & AC Mechanic (313A) 30 practice questions video

Watch on YouTube

Official Refrigeration & AC Mechanic (313A) exam blueprint

Published by red-seal.ca for the 125-question Interprovincial exam. These weightings decide how many questions you face in each area, so they decide where your study time belongs.

Major Work Activity	Questions	Share
MWA A: Performs common occupational skills	13	10.4%
MWA B: Performs routine trade activities	19	15.2%
MWA C: Plans installation	18	14.4%
MWA D: Performs installation	26	20.8%
MWA E: Performs commissioning	21	16.8%
MWA F: Performs maintenance and service	28	22.4%
Total	125	100%

Exam time 4 hours · pass mark 70%. Source: red-seal.ca official exam breakdown.

10-Question Refrigeration & AC Mechanic (313A) Quick Readiness Quiz — with Full Worked Answers

No sign-up and no email required. Take this 5-minute diagnostic quiz to test your current exam readiness. Every answer below includes complete code citations and worked steps — the same standard as the other 1240 questions in the full bank.

⚡ Interactive Readiness Quiz

Click any option (A–D) below to test yourself & reveal the worked explanation.

Question 1 of 10

At a supermarket distribution centre in Mississauga, a refrigeration mechanic must replace a burnt contactor on a 600 V semi-hermetic compressor on the parallel rack. The mechanic opens the compressor's disconnect, applies a personal lock and tag, and sees the rack controller show the compressor as offline. Before touching the contactor terminals, what must the mechanic do next?

A) Test each phase at the disconnect with a tester proven on a known live source

B) Test one phase at the contactor with a clamp meter set on its amps range

C) Test each phase at the contactor with a tester proven on a known live source

D) Check the rack controller again, and take the offline status as proof of no voltage

Correct answer: C

A lock on the disconnect does not prove the conductors are dead: the wrong switch may have been opened, or there may be a second feed. The absence of voltage is proven on every phase at the point of work, with a tester checked on a known live source. A test at the disconnect does not reach the contactor, a clamp meter shows current rather than voltage, and a controller status is not a test of the conductors.

Question 2 of 10

A mechanic in Lethbridge runs out of nitrogen halfway through brazing a liquid line. The apprentice suggests connecting the oxygen cylinder from the torch outfit to purge and pressure test the piping instead, since both are clean, dry gases, and the supplier is an hour away. What should the mechanic do?

A) Use the oxygen for the purge only, since it is a clean, dry gas at low flow

B) Stop and get more dry nitrogen, since oxygen can ignite oil in the system

C) Use the oxygen for the pressure test only, since no flame is near the system

D) Use shop air for the rest of the job, since air is mostly nitrogen anyway

Correct answer: B

Pure oxygen in contact with oil or grease under pressure can ignite or explode violently, and hot copper oxidizes in it. Only dry nitrogen, or another inert gas approved by the maker, is used for purging and pressure testing. Compressed air carries oxygen and moisture, so it is ruled out as well.

Question 3 of 10

As an apprentice forms a flare on a 1/2 in soft copper suction tube for a mini-split indoor unit in Fredericton, a split opens along the edge of the flare. The flare nut is already on the tube, and there is enough spare tube to cut back. In what order should the apprentice make a new flare?

A) Cut off the cracked end squarely; ream and deburr the cut end; check the flare nut is on the tube; then form the new flare, oil on the cone

B) Ream and deburr the cut end; cut off the cracked end squarely; check the flare nut is on the tube; then form the new flare, oil on the cone

C) Cut off the cracked end squarely; ream and deburr the cut end; form the new flare, oil on the cone; then check the flare nut is on the tube

D) Form the new flare, oil on the cone; cut off the cracked end squarely; ream and deburr the cut end; then check the flare nut is on the tube

Correct answer: A

A cracked flare will leak and cannot be repaired. The end is cut off square, reamed and deburred so it will not split again, the flare nut is confirmed on the tube, and a new flare is formed with a drop of refrigeration oil on the flaring cone. The other options use the same steps in the wrong order: B does 'ream and deburr the cut end' before 'cut off the cracked end squarely', C does 'form the new flare, oil on the cone' before 'check the flare nut is on the tube', and D does 'form the new flare, oil on the cone' before 'cut off the cracked end squarely'.

Question 4 of 10

While preparing for a rack replacement at a Chicoutimi store, a mechanic finds that the panel schedule has not been updated and two disconnects near the rack are unmarked. The compressed gas manifold and the steam line in the same room have valves with worn tags. What should the mechanic do about the isolation points?

A) Trace and confirm only the electrical points, and leave the rest unmarked

B) Trust the old panel schedule, and start work on the rack as it stands

C) Open each disconnect in turn, and see which of the store's systems stops

D) Trace and confirm each isolation point, and mark them before the work starts

Correct answer: D

Isolation points have to be known, not assumed, so unmarked or worn ones are traced and marked before work. An out-of-date schedule cannot be trusted, and opening disconnects to see what stops can shut down refrigeration or other store systems with no warning.

Question 5 of 10

A hospital isolation wing in Halifax needs its supply fan to keep running even if the fan's VFD fails. The engineer's design adds equipment to the drive panel so the motor can run straight from the line at full speed. In what order is the bypass used when the drive fails?

A) Lock out the failed drive's circuit; switch the bypass to across-the-line; start the motor through the bypass; then repair the drive, then return to drive

B) Start the motor through the bypass; switch the bypass to across-the-line; lock out the failed drive's circuit; then repair the drive, then return to drive

C) Switch the bypass to across-the-line; start the motor through the bypass; lock out the failed drive's circuit; then repair the drive, then return to drive

D) Repair the drive, then return to drive; lock out the failed drive's circuit; switch the bypass to across-the-line; then start the motor through the bypass

Correct answer: A

With a bypass, the failed drive is isolated, the selector or contactors are switched to across-the-line, and the motor is started at full speed through the bypass. The drive is repaired and the system returned to drive control afterwards. The other options use the same steps in the wrong order: B does 'start the motor through the bypass' before 'switch the bypass to across-the-line', C does 'start the motor through the bypass' before 'lock out the failed drive's circuit', and D does 'repair the drive, then return to drive' before 'lock out the failed drive's circuit'.

Question 6 of 10

A commercial cooler at a Lethbridge restaurant is cycling erratically, and the mechanic suspects the NTC thermistor that controls the compressor. The thermistor is rated 10 kohm at 25°C. Removed from the unit and left at a room temperature of 25°C, it measures 20 kohm. What has happened to the sensor, and how will the controller read the box temperature?

A) It has shorted inside, so the controller reads the box colder than it is

B) It has drifted high, so the controller reads the box warmer than it is

C) It has drifted high, so the controller reads the box colder than it is

D) It has gone open, so the controller reads the box warmer than it is

Correct answer: C

An NTC thermistor's resistance falls as temperature rises. A reading of 20 kohm at 25°C means it has drifted high, and the controller turns that higher resistance into a colder temperature than the real one. A short would read very low and an open would read infinite.

Question 7 of 10

An economizer on a rooftop unit at a Kitchener school stays at the same position no matter what the controller commands. The actuator turns fully and quietly when commanded, and its signal is correct, but the damper blades do not move. The mechanic sees that the actuator's shaft clamp is loose on the damper shaft. What is the fault?

A) The damper blades are frozen shut, so the actuator stalls every time

B) The actuator is undersized, so it cannot turn the damper blades

C) The controller signal is reversed, so the damper moves the wrong way

D) The actuator clamp has slipped, so it turns without moving the shaft

Correct answer: D

If the actuator runs its full stroke but the damper does not move, the connection between them has failed. The clamp is set with the damper at its closed position and the actuator at its zero, then tightened so they move together.

Question 8 of 10

On a supermarket rack in Sherbrooke, one case line has run warm since a service call last week, while the others hold temperature. The mechanic finds a large temperature drop across the line's suction stop valve, and the pressure upstream of it is well above the rack suction pressure. The valve's cap is off. What is the most likely cause?

A) The case line is overcharged and is backing up liquid into the suction

B) The stop valve was left partly closed and throttles the line

C) The rack suction pressure is set far too low for all of its case lines

D) The case thermostat has failed, so the case runs warm with no call

Correct answer: B

A suction valve left partly closed after service acts as a restriction: the pressure ahead of it rises and the case runs warm. The valve is opened fully, capped, and the case line's temperature checked.

Question 9 of 10

A mobile crane is lifting a heavy evaporative condenser onto the roof of a Brampton cold storage plant. Several crew members are on the roof and on the ground, and the load passes behind a parapet where the operator cannot see it. Who should give signals to the crane operator?

A) The site foreman by radio, even with the load out of view

B) Whichever worker is closest to the curb when the load arrives

C) Any worker on the roof who sees the load start to swing

D) One designated, qualified signaller who can see the load

Correct answer: D

Provincial crane rules require one designated, qualified signaller, using standard signals or a dedicated radio, who can see the load or is in contact with someone who can. Anyone may give an emergency stop, but no one else directs the lift.

Question 10 of 10

A clothing store in a single-storey strip mall in Moncton needs 7.5 tons of heating and cooling, but has almost no back-room floor space and cannot close the sales floor for long. The planner is choosing between a split system and a packaged rooftop unit. Which factor favours the packaged rooftop unit?

A) It needs no indoor floor space or field refrigerant piping, and is serviced on the roof

B) It needs long brazed refrigerant lines between the roof and an indoor air handler to work

C) It must be mounted inside the sales area, so it sits close to the cooling load

D) It runs without any power supply or condensate drain connection at all

Correct answer: A

A packaged rooftop unit contains the whole factory-charged refrigeration system outdoors, so it uses no floor space, needs no field refrigerant piping and is serviced from the roof, which suits a small store with little room.

313A Refrigeration & AC Superheat, Subcooling & CSA B52 Reference

Essential formulas, Canadian code standards, and critical numerical thresholds tested on the Interprovincial Red Seal Refrigeration & AC Mechanic (313A) exam:

HVAC/R Topic	Formula or CSA B52 Rule	Exam Application & Diagnostic Value
Evaporator Superheat Calculation	Superheat = Suction Line Temp − Evaporator Saturation Temp (from Suction P)	High superheat + low suction pressure = starved evaporator (undercharge or restriction)
Condenser Subcooling Calculation	Subcooling = Condenser Saturation Temp (from Head P) − Liquid Line Temp	Normal TXV subcooling: 5°C–8°C (10°F–15°F); low subcooling = undercharge
Coefficient of Performance (COP) & Compression Ratio	Compression Ratio = Absolute Discharge P (kPa abs) ÷ Absolute Suction P (kPa abs)	MUST add 101.3 kPa (14.7 psi) to gauge pressures before dividing!
Sensible & Total Heat (Airside)	Q_sensible = 1.08 × CFM × ΔT (°F) \| Q_total = 4.5 × CFM × Δh	1 Ton of Refrigeration = 12,000 BTU/hr = 200 BTU/min = 3.517 kW
CSA B52 Refrigerant Safety Classification	A1 = Lower toxicity, no flame (R-410A, R-134a) \| A2L = Mildly flammable (R-32, R-454B)	B1/B2 = Higher toxicity (R-717 Ammonia is B2L); requires machinery room ventilation
Deep Vacuum Evacuation Standard	Evacuate to ≤ 500 microns (250 microns for POE oil systems)	Standing decay rise that levels off = moisture; continuous linear rise = system leak

Worked examples: superheat, subcooling, airflow heat load and cylinder fill on the 313A exam

The 125-question blueprint focuses heavily on Performs maintenance and service (28 of 125 questions), Performs installation (26 of 125 questions) and Performs commissioning (21 of 125 questions). Charging diagnostics, sensible heat transfer and recovery cylinder limits are tested across all three blocks:

Worked example 1

At the evaporator outlet, suction pressure corresponds to a saturated temperature of 2 °C and the suction line thermistor reads 9 °C. At the condenser outlet, condensing saturation is 42 °C and the liquid line reads 36 °C. What are the superheat and subcooling?

Superheat = actual suction line temp − evaporator saturation temp = 9 − 2 = 7 K (7 °C). Subcooling = condensing saturation temp − actual liquid line temp = 42 − 36 = 6 K (6 °C).

Answer: 7 K superheat; 6 K subcooling. Always use bubble-point (liquid) saturation for subcooling and dew-point (vapour) saturation for superheat on zeotropic blends.

Worked example 2

An electric duct heater adds 51,180 BTU/h (15 kW) to an airflow of 1,200 CFM. What is the dry-bulb temperature rise across the heater?

Using the standard sensible heat formula Q = 1.08 × CFM × ΔT (°F): ΔT = 51,180 ÷ (1.08 × 1,200) = 51,180 ÷ 1,296 = 39.5 °F (≈ 21.9 °C).

Answer: 39.5 °F (≈ 21.9 °C).

Worked example 3

A recovery cylinder has a water capacity (WC) of 21.6 kg and a tare weight (TW) of 13.0 kg. What is the maximum safe gross scale weight when recovering a refrigerant with a liquid specific gravity of 1.06 at the 80% fill limit?

Max refrigerant mass = WC × 0.80 × SG = 21.6 × 0.80 × 1.06 = 18.3 kg. Max gross scale reading = tare + refrigerant = 13.0 + 18.3 = 31.3 kg.

Answer: 18.3 kg of refrigerant; 31.3 kg total scale weight.

Refrigerant safety groups, machinery room ventilation and pressure-relief requirements follow the CSA B52 Mechanical Refrigeration Code.

A 4-week study plan for the Refrigeration & AC Mechanic (313A) exam

18 new questions a day is the pace the platform sets, because spacing beats cramming. Over four weeks that is about 504 questions, and the order below follows the official weightings above.

Week 1 — the heaviest area. MWA F: Performs maintenance and service, which alone is 22.4% of the exam.
Week 2 — the next two. MWA D: Performs installation (20.8%) and MWA E: Performs commissioning (16.8%).
Week 3 — the remaining activities, plus every question you got wrong. Wrong answers return automatically on day 1, 3 and 7.
Week 4 — full-length timed runs. 125 questions in 4 hours, then review every mistake by Major Work Activity.

Booking the Refrigeration & AC Mechanic (313A) exam where you live

Eligibility and booking are handled by your province, not by the Red Seal program itself. Start here:

The full question bank

1250 Refrigeration & AC Mechanic (313A) questions, every one explained

You have just completed the 10-Question Readiness Quiz for Refrigeration & AC Mechanic (313A). To keep preparing for your 125-question Red Seal exam, unlock the full 1250-question bank with automatic Spaced Repetition (Ebbinghaus) and an AI tutor that explains every missed question.

🛡️ Instant Access · One-Time Payment · Free-Until-You-Pass Guarantee Backed

Frequently asked questions

How many questions are on the Red Seal Refrigeration & AC Mechanic (313A) exam?

The Interprovincial Red Seal Refrigeration & AC Mechanic (313A) exam has 125 multiple-choice questions, a 4-hour limit and a 70% pass mark, per the official exam breakdown on red-seal.ca.

Can I sample practice questions before subscribing?

Yes. You can download a free 30-question sample mock exam PDF with full step-by-step answer explanations. A subscription unlocks all 1250 questions, spaced-repetition review, and AI tutoring.

What's the best way to study for the Red Seal exam?

Consistent daily practice beats cramming. Read our Founder's Exam Prep Journey Blog Series to see how daily spaced repetition works in practice.

What does a subscription cost?

We offer a 7-Day Pass ($9.99 CAD one-time), a Monthly Pass ($29.99 CAD/month), and a 3-Month Pass with Free-Until-You-Pass Guarantee ($69.99 CAD one-time). All plans include daily adaptive practice, spaced-repetition review, and AI Journeyperson Tutor coaching.

What extra practice comes with the 3-Month Pass?

The 3-Month Pass adds two study tools for Refrigeration & AC Mechanic (313A). Practice by Block lets you pick any Major Work Activity on the official blueprint and drill it 18 questions at a time. Exhibit Booklet Practice gives you 12 questions that make you read tables, catalogs, test records and a walk-in cooler refrigeration piping schematic, with a worked explanation for every answer.