1. ACT, REGULATIONS AND CODES:

The candidate is expected to be able to locate information relating to the staffing, operation, maintenance, inspection, and testing of the compressor plant and its equipment resourcing the:

1.1 Technical Standards & Safety Act, 2000
1.2 Operating Engineers Regulation and Directors Orders
1.3 Boilers and Pressure Vessels Regulation
1.4 CSA B52: Mechanical Refrigeration Code
1.5 SA Z94.4 Selection, Care and use of Respirators
1.6 CEPA E2 Environmental Emergency Regulations

2. SAFETY:

The candidate is expected to be able to fully explain the dangers associated with the operation of a refrigeration plant and state the precautions to be taken to minimize or prevent such dangers.

2.1 gas detection and monitoring
2.2 gas exposure limits 2.3 personal protective equipment
2.4 basic WHIMIS
2.5 isolation (electrical & mechanical), confined space and fall protection

3. ADMINISTRATION:

3.1 mechanical drawing
3.2 maintenance planning
3.3 materials and welding
3.4 basic communication

4. FUNDAMENTALS:

The candidate must demonstrate an understanding of refrigeration fundamentals, including:

4.1 identifying basic thermodynamic principles
4.2 a basic understanding of gas behaviour
4.3 differentiating between CFC’s, HCFC’s and HFC refrigerants
4.4 an awareness of the environmental impact that each type of refrigerant can pose
4.5 a thorough understanding of the purpose of the components of a vapour compression refrigeration cycle
4.6 a thorough understanding of the compression refrigeration cycle, including the function of the:
4.6.1 -compressor -condenser -metering device -evaporator
4.7 the basic operating principle of an absorption refrigeration system
4.8 direct and indirect refrigeration systems
4.9 the use of secondary refrigerants, the mediums used and the applications of such coolants as used in the commercial and industrial sector
4.10 the essential qualities of a good refrigerant such as the main properties of:
4.10.1 -R-134A -R-22 -R-717 4.11 types of refrigeration systems and their associated equipment
4.11.1 -direct expansion -flooded -liquid overfeed -low pressure receivers -liquid recirculation pumps
4.12 lubrication principles

5. PUMPS & COMPRESSORS:

The candidate must demonstrate an understanding of compressors, including the:

5.1 main types of refrigeration compressors and have a basic understanding of each type, including packaged types
5.2 application and the types of “booster” compressors used within a two-stage or compound refrigeration system
5.3 main types of prime movers used to drive refrigeration compressors
5.4 difference between hermetic, semi-hermetic and open –type compressors
5.5 methods used to prevent leakage of refrigerant at the compressor shaft and of preventing liquid refrigerant from entering the compressor
5.6 different methods employed to control the “capacity” of the various types of refrigeration compressors, including start-stop, slide valves (variable clearance volume), variable frequency drives, etc.
5.7 two-stage centrifugal chillers
5.8 compressor cooling
5.9 main types of refrigeration pumps and a basic understanding of each type and principles

6. CONTROLS AND INSTRUMENTATION

Candidates must demonstrate an understanding of the controls and accessories, including:

6.1 basic computer control and instrumentation
6.2 six commonly used types of refrigerant flow metering devices used to control the flow of refrigerants
6.3 the operation of a thermostatic expansion valve
6.4 the function, principle of operation and the location(s) of the following controllers:
6.4.1 -temperature and/or pressure actuated -humidity actuated -evaporator pressure regulator -condenser cooling water regulating valve
6.5 the safety controls used in a refrigeration system, and the operation of each type, such as:
6.5.1 -high pressure cut-out -low pressure cut-out -oil failure protection -high discharge cut-outs -high oil temperature cut-out -motor overload devices
6.6 the function and location of the following components in a system:
6.6.1 -oil separators in reciprocating compressors -oil separators in screw compressors -suction strainers and scale traps -filter- driers -moisture indicators -crankcase heaters in reciprocating compressors and oil heaters in screw compressors -oil stills -purge and charging valves -pressure relief devices
6.7 the type of piping/tubing allowed for the different types of refrigerants
6.8 the use of receivers in a refrigeration system, their location, and the Code required safety fittings attached, including:
6.8.1 –high pressure receivers -low pressure receivers -intermediate or controlled pressure receivers
6.9 the methods employed to control humidity

7. CONDENSERS AND COOLING TOWERS

Candidates must demonstrate an understanding of condensers and cooling towers, including the:

7.1 different types of air-cooled and water-cooled condensers
7.2 evaporative type condenser and the effects of humidity on this type of condenser’s operation
7.3 main factors on which the rate of heat transfer is dependent on in a cooling tower
7.4 evaporative cooling effect and its consequences
7.5 need for water treatment and the water tests required
7.6 ability to recognize bacteria concerns associated with water sumps and what can be done to prevent associated risks

8. EVAPORATORS AND COOLING COILS

Candidates must demonstrate an understanding of evaporators and cooling coils, including the:

8.1 construction and application for each of the following:
8.1.1 -bare tube construction -fin and tube construction -plate type construction
8.2 chillers, including:
8.2.1 –shell & tube construction -plate and frame construction
8.3 differences between a “dry expansion” (also called “direct expansion”) and a “flooded expansion” and “liquid overfeed” evaporators
8.4 thermal storage systems

9. OPERATION AND MAINTENANCE

Candidates must demonstrate an understanding of operation and maintenance, including:

9.1 the refrigeration leak tests used
9.2 how you would start-up and shut down a single-stage refrigeration compressor
9.3 how air is removed from an operating system, including both manual and automatic purging
9.4 how to add oil to a running compressor and an understanding of basic refrigerant charging
9.5 some common reasons for the following conditions:
9.5.1 -failure of a compressor to start -causes for compressor short cycling -causes of continuous operation of the compressor under light loads or while system cooling is not required -discharge pressure too high or too low -suction pressure too high or too low
9.6 the maintenance requirements for compressors, system pumps, valves, metering devices, evaporators and condensers to ensure safe and continuous operation
9.7 the precautions to be taken when draining oil separators to prevent unsafe conditions
9.8 the methods used to defrost evaporators with the emphasis on industrial/commercial refrigeration defrost methods
9.9 what crystallization is with respect to absorption refrigeration systems
9.10 oil removal from refrigeration systems
9.11 pumping down systems
9.12 equipment isolation
9.13 low temperature receivers
9.14 low temperature liquid recirculation (liquid overfeed)
9.15 chemical treatment for condensers and cooling towers

10. ELECTRICAL

Candidates must demonstrate a basic understanding of electricity and calculations:

10.1 the use and function of the following electrical components: circuit breakers, relays, rheostats, fuses, electrical switches and safety cut-outs
10.2 the dangers and maintenance requirements of electric motors
10.3 the basic differences with motor starters and the application of different types

11. AIR CONDITIONING

Candidates must demonstrate an understanding of air conditioning, including:

11.1 the psychrometrics of air and the air conditioning factors that affect comfort
11.2 the ability to analyze/demonstrate on a psychrometric chart the behaviour of air when subjected to cooling, humidification and dehumidification
11.3 the different categories of air conditioning systems
11.4 how Legionnaires Disease can be drawn into ventilation systems and being able to recognize the effects of the disease

12. MATHEMATICS AND SCIENCE

12.1 elementary mathematics
12.2 elementary mechanics and dynamics
12.3 elementary thermodynamics
CALCULATIONS: The candidate should be able to perform basic refrigeration calculations to solve for compression capacity, ratio, cylinder volume, volumetric efficiency, system tonnage and calculations based on CSA B-52 Mechanical Refrigeration Code. Calculation questions will be stated so that they can be performed either in S.I. or in Imperial.