Red Seal Refrigeration & AC Mechanic case studies
Red Seal Refrigeration & AC Mechanic · Put your knowledge to work in context.
The Red Seal Refrigeration and Air Conditioning Mechanic credential is a Canadian interprovincial trade certification. It signals that a journeyperson has met a common national standard and may work across participating provinces and territories without rewriting each jurisdiction's certification exam. It is written for apprentices nearing completion, certified journeypersons adding the Red Seal endorsement, and experienced technicians formalizing skills gained on the job. The exam is multiple choice and samples the full trade: safety and environmental protection, tools and shop practice, refrigeration fundamentals, electrical and electronic controls, piping layout, refrigerants and lubricants, installation and commissioning, troubleshooting and repair, commercial and industrial systems, and air conditioning, heating, and air distribution. The Red Seal Refrigeration & AC Mechanic case studies are 5 cases and about 3,015 words.
1Recovery Cylinder Overfill and an Unknown Refrigerant
You are recovering R-448A from a medium-temperature supermarket rack that holds a 180 lb charge. The recovery cylinder on your scale is stamped TW 27.4 lb and WC 47.6 lb; the scale currently reads 74.0 lb at 68°F.
619 words, about 3 min2Three-Phase Rooftop Compressor Nuisance Trips
A 460 V, three-phase rooftop unit serving a sales floor has a 5-ton scroll compressor with an RLA of 18.5 A. The unit trips its compressor overload after 20 to 30 minutes, then resets and runs again.
599 words, about 3 min3Frost at the TXV on a 5-Ton R-410A Split System
A 5-ton R-410A split system with a TXV is not cooling a conference room. Indoor return air is 75°F dry bulb and 63°F wet bulb; outdoor ambient is 95°F.
596 words, about 3 min4Walk-In Freezer Defrost Termination and Floor Ice
A walk-in freezer holding frozen product at 5°F uses R-448A, electric defrost, and a 30-minute defrost period four times per day. The defrost termination sensor is set to terminate at 50°F coil temperature, and the fan delay is set to 45°F.
608 words, about 3 min5Nitrogen Pressure Test on a New 150 ft Line Set
You are pressure-testing a new 150 ft line set for a 20-ton packaged unit. The suction line is 1-1/8 in.
593 words, about 3 min