Refrigeration and Air Conditioning Mechanic (Red Seal)

Performs common occupational skills

What document replaced the older material data sheet for hazardous products in Canadian workplaces?

1. A material data sheet
2. A safety data sheet
3. A product spec sheet
4. A verbal hazard briefing

The standardized sixteen-section safety data sheet replaced the older material data sheet when the hazard-communication system was harmonized in 2015. It gives consistent information on hazards, handling, and first aid for products such as refrigerant lubricants. The older material data sheet is exactly what was superseded, a spec sheet covers performance not hazards, and a verbal briefing is not the required controlled document.

RSOS 2024 | A-1.01 Maintains safe work environment

Performs routine trade activities

What is the boiling point of R-404A at atmospheric pressure?

1. -26 deg C
2. -40.8 deg C
3. -51.6 deg C
4. -46.5 deg C

R-404A boils at -46.5 deg C at atmospheric pressure, suiting it to low-temperature commercial refrigeration. The -26 deg C value is closer to R-134a, -40.8 deg C belongs to R-22, and -51.6 deg C belongs to R-410A. This distinction matters in the field because applying the wrong rule wastes time, can damage equipment, and leaves the underlying fault unresolved, so the mechanic confirms the correct factor before acting.

RSOS 2024 | B-7.04 Uses refrigerants, gases and oils

Plans installation

Which compressor types are positive-displacement machines used in vapour-compression refrigeration?

1. Reciprocating, scroll, screw
2. Turbine type under normal operating conditions
3. Diaphragm type under normal operating
4. Centrifugal only

Reciprocating, scroll, and screw compressors trap and squeeze a fixed volume of vapour, which makes them positive-displacement machines common in refrigeration. A turbine and a centrifugal machine accelerate gas dynamically rather than displacing a fixed volume, and a diaphragm type is not a standard refrigeration compressor. In the field, confirming the correct factor first protects the equipment and prevents costly rework later.

RSOS 2024 | C-8.02 Selects HVAC/R equipment, components and accessories