Section 5 Control and monitoring and electrical power arrangements
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Naval Ships, January 2023 - Volume 2 Machinery and Engineering Systems - Part 11 Support Systems - Chapter 4 Refrigeration System Arrangements - Section 5 Control and monitoring and electrical power arrangements

Section 5 Control and monitoring and electrical power arrangements

Parent topic: Chapter 4 Refrigeration System Arrangements

5.1 General

5.1.1 Control engineering arrangements are to comply withVol 2, Pt 9, Ch 7 Control, Alerts and Safety Systems as applicable.

5.1.2 The equipment used in refrigeration systems is to be provided with local control and monitoring arrangements.

5.1.3 Where isolation of equipment or systems can be carried out, means of indicating the status of isolation is to be provided at positions where the equipment and system can be operated and monitored.

5.1.4 Instrumentation to indicate the operational status of running and any standby equipment is to be provided locally and at any control station.

5.1.5 All pumps are to be provided with an indication of discharge pressure and a low discharge pressure alarm at each control station.

5.1.6 Electrical engineering arrangements are to comply with Vol 2, Pt 9 Electrotechnical Systems as applicable.

5.1.7  Refrigeration compressors are to be provided with the following instrumentation and automatic shutdowns:

  1. Indication of suction pressure (saturated temperature), including intermediate stage when applicable.
  2. Indication of discharge pressure (saturated temperature), including intermediate stage when applicable.
  3. Indication of lubricating oil pressure.
  4. Indication of cumulative running hours.
  5. Automatic shutdown in the event of low lubricating oil pressure.
  6. Automatic shutdown in the event of high discharge pressure which is to operate at a pressure in excess of normal operating pressure but not greater than 0,9 of the maximum working pressure.
  7. Automatic shutdown in the event of a low suction pressure.

5.1.8 For refrigeration compressors greater than 25 kW, the following instrumentation, additional to that required by Vol 2, Pt 11, Ch 4, 5.1 General 5.1.7 is to be provided:

  1. Indication of lubricating oil temperature.
  2. Indication of cooling water outlet temperature.
  3. Indication of suction and discharge temperatures.

5.1.9 Alarms are to be initiated in the event of the following fault conditions with refrigeration compressors:

  1. High discharge pressure.
  2. Low suction pressure.
  3. Low oil pressure.
  4. High discharge temperature.
  5. High oil temperature.
  6. Motor shutdown.

5.1.10 Refrigeration plants are to be provided with the following alarms:

  1. Failure of condenser cooling water pumps.
  2. High condenser cooling water outlet temperature.
  3. Failure of air cooler fans.
  4. High and low chilled water delivery temperatures.

5.2 Refrigerant leak detection systems

5.2.1 A fixed refrigerant leak detection system is to be provided for any refrigeration machinery containing a mass of refrigerant that exceeds the practical limit for the volume of the compartment.

5.2.2 The leak detection and alarm system is to comply with the requirements of Vol 2, Pt 6, Ch 1 Steering Gear and Vol 2, Pt 9, Ch 11 Gas detection. As a minimum requirement, the system is to activate at a low-level concentration to give warning of refrigerant leaks, and at a high-level concentration corresponding to the practical limit for the refrigerant.

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