3A2E3 C1 Obj 7.pdf

r®- Chapter 1 • Legislation and Codes for Power Engineers OBJECTIVE 7 Describe the scope and general content of the CSA-B52 Mechanical Refngeration Code. INTRODUCTION TO CSA-B52 The CSA-B52 Mechanical Refrigeration Code is set up very much like CSA-B51. It looks very similar and its layout is muc...

r®- Chapter 1 • Legislation and Codes for Power Engineers OBJECTIVE 7 Describe the scope and general content of the CSA-B52 Mechanical Refngeration Code. INTRODUCTION TO CSA-B52 The CSA-B52 Mechanical Refrigeration Code is set up very much like CSA-B51. It looks very similar and its layout is much the same. References to CSA-B52 are written the same way as in CSA-B51. CSA-B52 is, and has been, developed in the same manner as other CSA Group standards. Technical committees that represent a varied cross-section of industry, jurisdictional authorities, and other interest groups are established, and the standards are developed through a consensus standards development process approved by the Standards Council of Canada," as stated in CSA-B52-18 (CSA Group, 2018). As was mentioned in the previous objective, references to the standard must include the edition that is being referred to. The edition of the standard that is being used must also have been declared in force by the jurisdiction in which it is being applied. There are 12 editions of CSA-B52; the most recent is CSA-B52-18. Check with your local jurisdiction to determine which edition is in force. CSA-B52 states that the standard provides the minimum requirements for the design, construction, installation, inspection, and maintenance of the mechanical refrigeration systems.. . The Code applies to all refrigeration systems installed, whether in new or existing premises, to systems that undergo a substitution of refrigerant, and to parts that are replaced in or added to the system" (CSA Group, 2018). This objective covers an overview of the clauses of the standard and some of the important highlights. The referenced standard for this overview is the full version ofB52-13. It is important to realize that, like CSA-B51, familiarity with the Mechanical Refrigeration Code will come only after reading the standard. This overview also refers to CSA-B52HB-16, A practical handbook for implementing CSA B52-13, Mechanical Refrigeration Code." This handbook is a user- friendly guide to the requirements of CSA-B52. CSA-B52 MECHANICAL REFRIGERATION CODE Preface to CSA-B52 The preface lists all the editions published and the changes and updates to the standard that have taken place since the last edition. The preface also reiterates that the standard does not have force of law until it is adopted by the jurisdiction. 1.Scope The scope sets the purpose of the standard, which is to keep people safe by providing standards for mechanical refrigeration. The scope also lays out which refrigeration systems the standard applies to and which systems it does not. For example, the standard does not apply to refrigeration systems installed on railroad cars, motor vehicles, or ships. 32 3rd Class Edition 3 • Part A2 Legislation and Codes for Power Engineers • Chapter 1 2. Reference Publications As in CSA-B51, all publications that are referred to in CSA-B52 are listed here, as well as the specific edition of the publications. 3. Definitions and Abbreviations Definitions and abbreviations used in this standard and common to the refrigeration industry are contained here. 4. System Selection and Application Requirements This clause is particularly important. It should be referred to after a refrigeration system has been selected in order to confirm that it complies with code requirements. When a refrigeration system is designed, it must meet certain requirements related to the refrigerant group being used, the system leakage probability, and the occupancy classification of the building. Each of these requirements is described in this clause. A flow chart to aid in the identification of system requirements is included. Refrigerants are placed in safety groups based on flammability and toxicity. The matrix used to classify refrigerants is included in Clause 4. This clause also describes, using words and diagrams, different refrigeration system classifications by type (direct, indirect, double direct, etc.). Note: Editions of CSA-B52 from 2013 and later do not include many older types of refrigerants in Clause 4. Refrigerants such as Rll, R12, R22, and others are not typically used in new installations any more. However, if these infrequently-used refrigerants are to be used, they must meet the same Clause 4 requirements as newer refrigerants. The information needed for these older refrigerants is found in a non- mandatory (informative) annex at the end of CSA-B52. 5. Equipment Design and Construction Clause 5 states that pressure vessels must be designed, constructed, and tested according to CSA-B51. Drawings and specifications must be submitted to the jurisdictional authorities for acceptance and registration. Clause 5 also exempts systems of 125 kW or less from registration if certain conditions are met. Other important sections of this clause include the following: • Material specifications • Design pressures • Requirements for refrigerant piping, fittings, coils, etc. • Posting of instructions 6. Installation Machinery room requirements are laid out in Clause 6 and include the following: • Doors • Explosion protection • Ventilation • Class T machinery rooms. Class T machinery rooms are designed as unoccupied spaces with restricted access and are subject to specific restrictions and requirements. An ammonia (R-717) refrigeration system would be enclosed in a Class T machinery room. 3rd Class Edition 3 • Part A2 33 ?& Chapter 1 • Legislation and Codes for Power Engineers 7. Overpressure Protection Clause 7 states that the pertinent rules of ASME Section VIII must be followed with regards to pressure-relief protection of refrigeration system pressure vessels. The clause also lays out the following: • Overpressure protection requirements based on internal volume of pressure vessels • Requirements for the setting ofpressure-limiting devices • Locations where pressure-relief devices must be fitted • Requirements for the discharge of pressure-relief devices, including a separate mention of ammonia systems 8. Maintenance of Systems Requirements for the charging and discharging of systems can be found in Clause 8. Regarding the maintenance of the system, the standard specifies that the owner or their representative is responsible for ensuring that the maintenance is done by a certified (qualified) person. In addition, the maintenance must be done in accordance with the operation and maintenance manuals. If no manual exists, the maintenance must be done as per the following: • The applicable regulation such as the Environmental Code of Practice for the Elimination of Fluorocarbon Refrigerants in the Air Conditioning and Refrigeration Industry, or • The maintenance requirements that are laid out in CSA-B52-13, Clause 8.4.2 9. Precautions This short clause lays out some requirements that are intended to keep personnel safe (e.g., personal protective equipment, cold-storage room doors, and alarms). Annexes CSA-B52 includes several informative (non-mandatory) and normative (mandatory) annexes that cover topics such as the following: • Guidelines for emergency discharge of refrigerants (informative) • Working with R-744 (COz) systems - precautions and potential hazards (normative) • Characteristics of carbon dioxide (informative) The following questions can be answered using CSA-B52-09 or CSA-B52-13. Include the complete reference for your answer. Self-Test 1 What is the definition of a pipe duct7 34 3rd Class Edition 3 • Part A2 Legislation and Codes for Power Engineers • Chapter 1 3rd Class Edition 3 • Part A2 ^