System Troubleshooting & Safety Flashcards

What does the CSA B52 Mechanical Refrigeration Code govern in Canada?

Answer: The design, construction, installation, and testing of refrigeration and air conditioning systems in Canada

CSA B52 is the Canadian standard that governs the design, construction, installation, testing, and maintenance of mechanical refrigeration systems, and it is adopted by provincial codes across Canada.

What is a 'pressure test' as performed under CSA B52 after installing a new refrigeration system?

Answer: Pressurizing the system with dry nitrogen to the test pressure specified in CSA B52 to verify the integrity of the refrigerant circuit before introducing refrigerant

CSA B52 requires a pressure test using dry nitrogen (never oxygen or refrigerant alone) to a specified test pressure before refrigerant is introduced, verifying that all joints, fittings, and components are leak-free and structurally sound.

What does an electronic leak detector indicate when it sounds an alarm near a refrigerant line?

Answer: Detection of refrigerant vapour concentration above the instrument's threshold at that location

An electronic leak detector senses refrigerant vapour concentration and alarms when it exceeds the instrument's sensitivity threshold, indicating a likely leak source that the technician should confirm and repair.

What is the recommended method to confirm a refrigerant leak location after an electronic detector gives an alarm?

Answer: Apply an approved refrigerant-compatible leak detection solution (bubble solution) or use a UV dye and UV light to pinpoint the exact leak location

After an electronic detector alerts to a possible leak, bubble solution or UV dye with a UV lamp is used to pinpoint the exact location; UV dye that was pre-charged into the system glows brightly at the leak site under UV light.

Why must oxygen (O2) never be used to pressure test a refrigeration system?

Answer: Oxygen reacts with refrigerant oils to form an explosive mixture that can detonate under pressure

Oxygen mixed with refrigerant oil vapour under pressure creates a potentially explosive mixture — this hazard has caused fatal accidents, and all codes absolutely prohibit using oxygen or air to pressure test refrigeration systems.

What is the purpose of a relief valve on a refrigeration pressure vessel under CSA B52?

Answer: To automatically vent refrigerant if internal pressure exceeds a safe limit, preventing catastrophic vessel rupture

A relief valve is a code-required safety device that automatically opens to release refrigerant when vessel pressure exceeds the design limit, preventing a potentially catastrophic mechanical failure of the pressure vessel.